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Category Archives: Passive House

Blower Door (Air Sealing #9 )

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When it was time to schedule our blower door test we considered using Eco Achievers, but we only knew about them because they’ve worked extensively on projects for our original builder, Evolutionary Home Builders. We decided the potential awkwardness, or even a possible conflict of interest, wasn’t worth pursuing their services. An example of guilt-by-association I suppose, one that is probably unfounded, but, nevertheless, the strong affiliation with our original builder made it difficult for us to reach out to them for help. They also hired one of Brandon’s former employees (this employee was nothing but nice and professional towards us as we were deciding to part ways with Brandon), which would’ve only added another layer of awkwardness to the situation.

Unsure how to proceed, I looked online and found Anthony from Building Energy Experts. He was able to come out and do a blower door test for us, helping me hunt down a couple of small leaks, so that we ended up at 0.34 ACH@50 for this initial test.

Here’s a Hammer and Hand video discussing the use of a blower door:

On a side note: all of the Hammer and Hand videos, along with their Best Practices Manual, were incredibly helpful as we tried to figure out all the Passive House details related to our build. It’s no exaggeration to say that without Hammer and Hand, the Green Building Advisor website, BSC, and 475 HPBS, our build would’ve been impossible to accomplish on our own. I owe an incredible debt of gratitude to all of these great resources who invest valuable time sharing such a wealth of information.

Below is a Hammer and Hand video noting the importance of properly detailing corners to avoid air leaks:

Because of this video, I sealed all of my corners for the windows and doors like this:

HF Sealant in corners b4 blower door

Adding Pro Clima HF Sealant after completing taping of the corner, just for added insurance against potential air leakage.

I also added some HF Sealant to the lower portion of the windows, since some air leakage showed up in this area with Anthony where components of the window itself come together in a seam.

sealant on wdw components junction

Seam near bottom of window where components meet — sealed with HF Sealant.

Where components come together is often an area that needs special or further attention.

close up corner and wdw components seam w: sealant

Close up of this same area — seam in components sealed, along with the bottom corner of the window and the gap between window buck and window.

Even with layers of redundancy in place, in the picture below there was a small air leak still present at the bottom plate – sub flooring connection. A coating of HF Sealant easily blocked it.

Once the stud bays were insulated (after most of the siding was up), the interior walls would eventually be covered with Intello (I’ll cover the details in a future post on interior insulation), adding yet another layer of redundancy for mitigating potential air intrusion.

area of kitchen sill plate leakage

Area of kitchen sill plate leakage.

Anthony didn’t have any previous experience with a Passive House build, so it occurred to me that it might be beneficial to reach out to Floris from 475 High Performance Building Supply (he had already done our WUFI analysis for us), and Mike Conners from Kenwood Property Development to see if there was someone locally who did. Mike is a Passive House builder in Chicago who had already helped me out with some Rockwool insulation when we came up short earlier in our project (the two GC’s we fired repeatedly struggled with basic math), and he was very nice to take the time to answer some other technical questions for me as well.

Both, as it turned out, ended up recommending that I contact Steve Marchese from the Association for Energy Affordability.

Steve would eventually make three trips to the house, doing an initial blower door test after the structure was weather-tight and all the necessary penetrations had been made through our air barrier, a second test after exterior continuous insulation was installed, and a final test after drywall was up to ensure there hadn’t been any increase in air leakage during the final stages of construction.

Steve starting blower door test

Steve setting up the blower door for his first test.

Following Passive House principles for our build, we also followed the same protocols for the blower door tests: Blower Door Protocol

With the structure under pressure from the blower door fan, Steve and I walked around the house while he used a small smoke machine in order to try and find any leaks that I could then seal up.

Steve testing window gasket

Steve starting at the windows. Here testing a window gasket for air leakage.

The gaskets around our windows and doors proved to be some of the weakest areas in the house although, comparatively speaking, it was inconsequential since the overall air tightness of the structure was fairly robust (favorite word of architects).

Steve showing impact of unlocked window

Steve showing me the impact a window in the unlocked position can have on air tightness. The gasket, ordinarily squeezed in the locked position, works to bring the sash and the frame tightly together.

 

Steve smoke at family rm wdw

Looking for areas around the windows that might need adjusting or additional air sealing.

For instance, even though no substantial air leakage showed up around this kitchen door, during our first winter this same door eventually had ice form outside at the upper corner by the hinges, on the exposed surface of the gasket where the door meets the frame.

Steve at kitchen door

After figuring out how to adjust the door hinges, there was no longer any ice showing up this winter, not even during our Polar Vortex event in late January.

Much the same thing occurred around our front door as well, with the same solution — adjusting the hinges to get a tighter fit at the gasket between the door and the frame.

Steve testing attic hatch

Steve testing the attic hatch for air leaks.

Steve was nice enough to go around and methodically check all the penetrations in the structure.

Steve testing plumbing vent in kitchen

Steve testing for air leaks around the kitchen plumbing vent and some conduit.

 

Steve testing for air leaks @ radon stack

Steve testing for air leaks around the radon stack.

 

Steve @ radon stack close up

Close up of radon stack during smoke test.

There was one area in the guest bathroom where the Intello ended up getting slightly wrinkled in a corner during installation. With Tescon Vana and some HF Sealant I was able to address it so nothing, thankfully, showed up during the smoke test.

Steve testing wrinkled area of Intello

Steve testing area of Intello that I inadvertently wrinkled during its installation.

After looking around on the main floor, Steve moved down into the basement.

Steve testing for air leaks @ main panel

Checking for leaks at the main electrical panel.

 

Steve testing for air leaks @ main panel exit point

Checking for leaks at the conduit as it exits the structure.

 

Steve testing for air leak @ sump pit cap

Looking for air leakage around the sump pit lid.

The lids for the sump pit and the ejector pit were eventually sealed with duct seal putty and some Prosoco Air Dam.

Steve testing for air leaks @ ejector pit

Testing the ejector pit for air movement.

 

Steve testing for air leaks @ Zehnder exit point

Checking for air leakage around one of the Zehnder ComfoPipes as it exits the structure.

 

Steve testing for air leaks @ pvc:refrigerant lines

Looking for air leaks around the heat pump refrigerant lines as they exit the structure.

 

Steve smoke at sump discharge

Checking around the penetration for our sump pump discharge to the outside.

Before the second blower door test, I was able to add some duct seal putty to the lids of the sump and ejector pits.

ejector pump lid w: duct seal

Ejector pit lid with some duct seal putty.

Below is a copy of Steve’s blower door test results, showing the information it provides:

Final Blower Door Test Results

For the last two tests Steve used a smaller duct blaster fan in order to try and get a more precise reading for air leakage.

Steve at front door

With Steve just after the initial blower door test was complete.

Steve would be back two more times — once before drywall, and once after drywall — just to ensure we had no loss of air tightness develop in the interim stages of the build (especially after continuous exterior insulation with furring strips were installed).

Here are the final figures noting where we ended up:

0.20 ACH@50 and 106 cfm@50

We are well below Passive House requirements (both PHI and PHIUS), so there was a great sense of relief knowing that all the time and effort put into air sealing had paid off, giving us the tight shell we were looking for. Even so, it was still pretty exciting news, especially for a first build.

And here’s an interesting article by 475 HPBS regarding the debate over how air tightness is calculated for PHI vs. PHIUS projects, and the potential ramifications: Not Airtight

 

 

 

Dressing up the Basement: Steel Beam and Concrete Walls

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With the Zehnder and the Mitsubishi systems installed, I had some time to kill waiting for the siding guys to start, and for my first blower door test to take place, so I moved on to painting my structural steel beam and the exposed concrete walls in the basement. Apart from a couple of walls for my wife’s office that would eventually be drywalled and painted, and a decorative finish for the concrete floor, these were going to be some of the limited finished surfaces in the basement.

We’re glad we decided to leave the basement ceiling unfinished. In doing so, not only did it mean a more straightforward installation process for mechanicals, it also means if any issues develop in the future we’ll have easy access to identify and solve any problems.

I debated whether or not to spray the basement ceiling — the floor joists and the underside of the sub flooring — but decided the color change (some shade of gray?) wasn’t worth the effort.

Although obviously not to everyone’s taste, we like the unfinished look of the ceiling, especially when combined with the texture of the painted concrete walls and our painted steel beam (not to mention the eventual decorative finish for our concrete floor slab — I’ll go through the details in a future blog post since it was applied much later in the build).

For the beam, I first used a wire brush and some sandpaper to remove any loose and flaking rust. Using a Sherwin Williams primer, their All-Surface Primer tinted gray, I applied a heavy, uniform coat to help prevent the return of any rust in the future (keeping humidity in the basement under control should help a lot in this regard).

beam w: primer and rusty red

After wire brushing off loose rust, priming the beam in preparation for paint.

After priming, I then applied two coats of a Safecoat product, their semi-gloss in Patriot Blue.

Safecoat semi-gloss Patriot Blue for steel beam

Patriot Blue for the steel beam.

If I could do it over, I think I’d use Safecoat primers and paints for almost all of the interior surfaces. For the sake of convenience, since they have stores near me, I mainly used Benjamin Moore’s Aura Matte and Satin for walls and trim, and ended up mostly disappointed with their performance — hiding is pretty mediocre, flashing when you try to do spot touch-ups, and over-priced for the level of quality. Benjamin Moore does a great job with their marketing materials and with the look of their labels, I just wish the same level of thought and attention to detail went into the quality of their finishes.

Safecoat is available in various stores in the US, but unless you want a stock white, tinting may happen at Safecoat headquarters before shipping to individual stores, so there can be a wait involved (check with your local supplier for details). I had good luck ordering from Green Building Supply in Iowa. After ordering online, the products are shipped directly to the job site or your home. And it gives you access to high quality no or low VOC products that, at least in my case, are otherwise unavailable in local hardware or paint stores.

Unfortunately, they can’t ship during cold spells, since the paint could freeze and be ruined. When it was cold and I needed product, I found Premier Paint and Wallpaper just outside of downtown Madison, Wisconsin (about a 2 hour drive for us). They’re a family-owned shop, and it shows. They have a nice selection of Safe Coat products. In fact, their wide range of products from various brands is impressive, and the people who work there are really helpful and just easy to work with. Unfortunately, I haven’t found a similar paint store in my area. Around me, Benjamin Moore (aka JC Licht), Sherwin Williams, and Pittsburgh Paint stores dominate the market. The smaller mom-and-pop stores, for the most part, don’t really exist anymore, which is a shame.

beam w: primer and paint

Paint going over the primer.

The Safecoat products that I’ve used typically have some odor, but what little smell they do have tends to dissipate rather quickly (this is particularly noticeable if you change back to a more conventional coating with more VOCs that may take weeks before its distinct odor finally disappears).

painted beam w: zehnder and hpump

Finished beam.

It’s a shame that so many structural beams end up covered over, normally considered too humble (i.e., ugly) to be left alone. In keeping with our Urban Rustic design aesthetic, we think that if they’re given even just a little bit of attention and care they can prove to be a real visual asset to a space, especially in a basement if a more relaxed, informal look and feel is acceptable or even ideal.

cu paintd beam in basement

Close up of the painted I-beam.

Leaving the spine of the house exposed like this with a bold color emphasizes the job it’s actually doing, and it honors the material by making it front and center visually in the space, rather than trying to hide it away behind drywall or wood. After all, beams like this are helping to keep the house upright.

basement walls primed

Another view of the beam, and the recently primed concrete walls.

Once the beam was completed, I moved on to priming the exposed concrete walls.

beast helping me prime basement

Getting some help priming the concrete walls. She lasted about 15 minutes, at which point it clearly turned into work.

Paint color can be a finicky thing. After priming the concrete walls, I used a Benjamin Moore color, Jute, as the finish coat. In the basement it looks great, exactly what we were looking for: a nice, warm neutral khaki color. Upstairs, however, when I later did a test swatch on the new drywall this same color looked horrible, taking on pinkish flesh tones, so we ended up having to use a different color for most of the first floor. Testing out colors, even in relatively small areas, can save a lot of time, money, and headaches later on.

painted basement walls

Concrete walls painted.

With a good chunk of the basement complete, it was time to move outside and get some work done before the siding began, and before we had our first blower door test.

HVAC (Part 2 of 2): Ductless Mini Split

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System Requirements

The plan for our house was to combine an HRV or an ERV (for a continuous supply of fresh air), with a ductless mini split air source heat pump system for our ventilation, heating, and air conditioning needs. Almost all of the projects I had read about utilized this same combination, especially here in the US.

The only real debate, apart from specific brand options, was whether or not to utilize only one distribution head on our main floor, as opposed to installing multiple heads for a more ‘dialed-in’ level of comfort (e.g., in the basement, or the bedrooms).

Our original builder had in our construction drawings one head in the kitchen/family room and one in the basement, which was pretty standard for a Passive House level project. It was, therefore, pretty shocking to find out that our second builder (there were two partners) and their HVAC subcontractor were suggesting a system that was grossly oversized for our needs. You can read about the details here: GBA: Oversized System 

This was just one of many ‘red flags’ that convinced us to move on and GC the project ourselves. It’s also a reminder that old habits die hard, meaning even seasoned contractors, in any trade, need to be willing to learn new ideas and techniques if they want to truly be considered professionals and craftsmen — unfortunately, they’re the exception to the rule, at least in our experience.

One of the disappointments associated with our build is, in fact, the disinterest (in some cases even outright hectoring contempt) shown by various tradespeople in our area for ‘green’ building generally. Doubtless, at least a partial explanation for why much of the Midwest seems so far behind in adopting ‘green’ building techniques, especially when it comes to air sealing, insulation, and IAQ beyond code minimum standards. Hopefully this changes significantly in the coming years.

Consequently, I took Steve Knapp’s advice (from the comments section of my question) and contacted Home Energy Partners (their new name: HVAC Design Pros). Isaac responded quickly and eventually did our Manual J, confirming we needed a much smaller system, one that is more consistent with a Passive House project, or even just a high-performance build more generally.

Here are a couple of Matt Risinger videos detailing a mini split set-up that’s fairly typical for a Passive House or a Pretty Good House (GBA article on the 2.0 version).

 

Once we were on our own, in addition to going with a Zehnder ERV and a Mitsubishi ductless mini split air-source heat pump system, we also pursued the possibility of using a Sanden heat pump water heater.

After seeing it used on a Hammer and Hand project, we thought it was a really interesting piece of cutting edge technology:

Unfortunately, after getting a quote from Greg of Sutor Heating and Cooling, and a poor response from Sanden regarding questions we had about the system (they were unresponsive to emails), we decided to stick with our Zehnder, the Mitsubishi heat pump, and then go with a Rheem heat pump water heater (going with the Rheem saved us just over $6,000 in initial cost). Hopefully, as it becomes more popular in the US, the Sanden can come down significantly in price, or maybe less expensive copycat products will someday show up on the market.

Greg was initially willing to work with us, even though we were technically out of his service area, when the Sanden was involved, but once it was only a ductless mini split he suggested we find a Mitsubishi Diamond installer closer to us, which we understood. He was nothing but professional, taking the time to answer any number of technical questions and offering what proved to be sage advice regarding various details for our system.

In fact, taking Greg’s advice, we contacted a Diamond installer close to us, but unfortunately the first installer we contacted disappeared when we were trying to get him to communicate with our electrician on installation details (an infuriating and painfully common experience when trying to build a new house — especially one with unconventional Passive House details).

 

 

Finding our Installer

At this point, we were lucky to find Mike from Compass Heating and Air. He came out to the job site and we walked through the details together. He proved to be knowledgeable, helpful, detail-oriented, and extremely professional. Installing our Mitsubishi ductless mini split system with Mike proved to be one of the easiest portions of our build. We never felt like we had to look over his shoulder, making sure he got details right, or that we had to constantly confirm that he did what he said he was going to do — in fact, it was the opposite: ‘Mike’s on site, so that’s one less thing I have to worry about’.

Compass truck on site

Mike and his crew at the job site to install our Mitsubishi ductless mini split system for heating and air conditioning.

Mike also confirmed what Greg and Isaac also pointed out: comfort issues may develop if we tried to get by with just one distribution head on the main floor.

In fact, looking back through old emails, Greg was nice enough to walk me through some of the options employed by those trying to get by with a single head for an entire floor (sometimes even two floors), including leaving bedroom doors open throughout the day (ideally, even at night), and even the use of Tjernlund room-to-room ventilators.

Again, to his credit, Greg tried to stress how important it was that homeowners have realistic expectations regarding the overall effectiveness of these techniques and options.

He also was at pains to make clear how the work of any competent HVAC installer can be easily undermined by a structure that underperforms. In other words, they can design an appropriately sized HVAC system for a Passive House, but if shortcuts occur during the build and the final blower door number comes in higher than expected, or the budget for insulation gets cut, reducing R-values in the structure, then the system they designed has little chance of working as intended. Based on what he wrote, I’m guessing he has dealt with exactly this outcome in the real world — not fun for him, or the homeowners to be sure.

Consequently, by the time Mike from Compass Heating and Air got involved, we had pretty much already settled on using multiple heads. Although it was nice to hear the same consistent message from Greg, Isaac, and Mike in this regard.

In the end, we decided to delete the head in the basement, instead going with three separate heads on the main floor — the largest in the kitchen/family room, and then the other two would go in our bedrooms.

Here are the specs for our system:

Hyper-Heat Compressor (30,000 Btu)

MSZ-FH15NA  (kitchen/family room)

MSZ-FH06NA  (master bedroom)

MSZ-FH06NA  (2nd BR)

head in mbr w: section of drywall

Master bedroom Mitsubishi head and Zehnder supply, both covered to protect against construction debris.

Having the Zehnder supply diffusers on the same wall and near the head of the Mitsubishi has been working well for us. As far as we can tell, there are no discernible issues with this arrangement. By way of comparison, the Mitsubishi head and Zehnder supply diffuser are on separate walls in my daughter’s bedroom — in effect, they’re pushing air towards the center of the room from walls that are perpendicular to one another — but we can’t tell any difference in terms of performance, either when heating or cooling.

mbr and family rm erv:heads construction

Facing camera: Family room Zehnder supply diffuser with Mitsubishi head. To the left, and facing MBR — Zehnder supply and lines for another Mitsubishi head.

Mike was also really good about communicating the system’s requirements to our electrician and our plumber. It was nice to watch all of them walk through the details together, thereby ensuring there were no problems once it came time to start up the individual heads.

condensate and refrigerant

Components for setting up a ductless mini split: refrigerant lines, electric supply, and a drain for condensate.

 

 

Living with a Ductless Mini Split

Having lived with the HVAC system, both the heat pump and ERV, for about a year now, our only real complaint is summer humidity, which I discussed in a previous post here: HVAC (1 of 2): Zehnder ERV

This summer we’re going to try using a dedicated, whole-house dehumidifier, which we think should resolve the issue.

Otherwise, our system has been trouble-free.

In winter, the heads do make some noise, tending to ‘crack’ or ‘pop’, especially when first turning on, or when they come out of defrost mode. Although I’ve read complaints about this online, it’s never really bothered us. I remember how loud our conventional gas-fired furnace was in our last house, especially when it first turned on, so I think it’s important to remember the level of certain sounds in their appropriate context.

Also, this ‘crack’ or ‘pop’ sound is, I suspect, louder than it otherwise would be say in a conventionally built home, since Passive Houses are known to be significantly quieter because of all the air sealing and, in particular, all of the insulation surrounding the structure.

There’s also a noticeable humming sound when the compressor is going through a defrost cycle (especially noticeable at night when the house is otherwise quiet). The heads also temporarily send out cooler air during this defrost cycle, but the cycle is short enough that it hasn’t posed any real comfort issue for us.

heat pump being installed on pad

Setting up the compressor outside.

Regarding interior noise generally, the same holds true even for our refrigerator in the kitchen. We virtually never noticed the fridge in our last house when it was cycling, but in our Passive House it’s arguably the loudest, most consistent noise in the house, especially at night, or if quietly sitting and reading. Again, it took some getting used to, but not really that big of a deal.

In other words, having blocked out, or at least muffled, most of the noise from outdoors (due to extensive air sealing and extensive insulation), any noise indoors becomes much more noticeable and pronounced. The Rockwool we installed between bedrooms-bathrooms, and the kitchen-utility room for sound attenuation definitely helps in this regard (more on this in a later post).

ext line set fully sealed

Line set for the heat pump system exiting the structure after being air sealed.

Just how quiet is a Passive House? Well, one example would be the train tracks that are just a couple of blocks away: When the windows are closed the noise from a passing train is mostly cancelled out — as opposed to when the windows are open, and the train, in contrast, sounds like it’s thundering through our next door neighbor’s yard.

pvc tied down w: duct seal

Interior view of the line set exiting the house.

As far as extreme cold outdoor temperatures are concerned, the system experienced a real test with our recent Polar Vortex weather. Mike was nice enough to check in with us the day before it started just to remind me that the system could shut down if temperatures fell below -18° F, which is what our local weather forecast was predicting.

In fact, this proved entirely accurate. As temperatures eventually fell to -24° F overnight, the system was, in fact, off for a few hours (the Mitsubishi shuts off to protect itself).

With the Zehnder ERV already set to LOW, and using just a couple of small space heaters (one in each bedroom — roughly equivalent to running 2 hair dryers simultaneously), it was easy to get the interior temperatures back up to 68-70° F in less than an hour (from a measured low of 61° F when we first woke up), at which point we turned off the space heaters.

And it was just under 2 hours before the temperatures rose enough outdoors for the heat pump to turn back on. On the second day, the system again turned off, but the interruption was even shorter this time, so we didn’t even bother to turn on the space heaters.

On both days the sun was shining, which definitely helped as light poured in through our south-facing windows, mainly in the kitchen and family room. Even with no additional heat, either from the heat pump or the two small space heaters, the kitchen remained a comfortable 70° F throughout that first day, regardless of the temperature outside.

In the summer, when we have the AC running, we just set the desired temperature on the remotes and largely forget about the system. The three heads together, even in each individual space, have no problem keeping the house and individual rooms cool enough. In this case, it no doubt helps that we have a substantial overhang on the southern portion of our roof, mostly denying the sun an entry point into the home during the hottest days of the year (and the Suntuitive glass on our west-facing windows takes care of afternoon summer sun).

conduit for heat pump thru zip

Conduit for the heat pump exiting the house and air sealed with Roflex/Tescon Vana tape and gasket.

You can see more detailed info regarding air sealing penetrations through the Zip sheathing here: WRB: Zip Sheathing

refrigerant condensate next to beam

Clean, neat lines for the heat pump.

 

 

Single or Multiple Heads?

As far as using a single head to try and heat and cool the entire first floor, in our case about 1500 sq. ft., I can only say that I’m glad we chose to use multiple heads. This really hit home as I was completing interior finishes. For instance, there were times when only the head in the family room/kitchen area was running. When you walked into the bedrooms you could definitely feel the temperature difference since those heads had been turned off (roughly a 5-10° difference). As Greg, Isaac, and Mike — to their credit — were all quick to point out, for some homeowners this temperature swing would be acceptable, even something that could be calmly ignored, while for other homeowners it might well be a heartbreaking and deeply frustrating realization.

Depending on how sensitive someone is to these temperature differences, it could  prove a devastating disappointment if the homeowner is expecting uniform consistency throughout their home. Also, since much of the selling point of Passive House techniques is, in the end, occupant comfort, and not just reduced energy consumption, moving from a comfortable kitchen, for example, to a bedroom that some would find outright chilly, might induce some homeowners to ponder: ‘What was the point of all that air sealing and insulation if I’m still cold in the wintertime and hot in the summer?’ If they hadn’t been warned beforehand, like we were, it would be difficult to argue with their reasoning.

Obviously it’s only our opinion, but if it’s at all possible to fit it into the budget, by all means utilize more than one distribution head. Even if you yourself never feel compelled to turn on any of the other heads in a multi-zone system, a spouse, one of your kids, or a guest probably will want to have the option at some point.

cu beam w: zehnder and hp

Zehnder ComfoTubes and various lines for the heat pump as they enter the basement from the MBR and the family room.

In addition, I would also guess that when going to sell the house multiple heads would be significantly easier to sell to a potential buyer (who wouldn’t appreciate customized HVAC in specific rooms?) rather than trying to prove that a single head is sufficient for an entire home, no matter how small or well-designed. Thoughts worth considering before committing to a specific HVAC system.

north facade w: siding

Compressor with finished charred siding and decorative gravel-cobblestone border.

Also worth noting, utilizing the Q&A section of the Green Building Advisor website is an excellent resource for exploring options before committing to a final HVAC set-up. It’s an excellent way to hear from designers and builders who have experience with multiple ‘green’ projects, not to mention actual homeowners who live in high-performance homes and experience these HVAC systems in the real world, as opposed to just data points put into a proposed energy model (incorrect inputs, along with actual occupant behavior are just two ways a potential system could end up being profoundly inappropriate). This kind of feedback — before construction begins — is undeniably priceless. In fact, I regret not asking more questions on GBA as they came up during the design and construction phases of our build since it is such a valuable resource of useful information.

compressor in snow

View of the same area after our recent Polar Vortex (snowfall, then below zero temps).

The one real risk we took with our HVAC set-up was foregoing any direct conditioning in the basement, either heat or AC. In the summer, no matter how high the temperatures outdoors, the basement stays within 5 degrees of the upstairs temperatures and humidity, so no comfort issues in this regard have presented themselves. In the winter, however, the temperature remains in the 59-61° range, with almost identical humidity readings as the main floor.

ice under unit

Some ice build-up, but almost all of it on the concrete pad below, not on the compressor itself.

Most of the time this isn’t a problem for us, since we’re either working out (the slight chill gets you moving and keeps you moving), or else we’re doing arts and crafts projects, or reading on a couch under a blanket. The only time the chill gets annoying is when sitting at the computer for an extended period of time, so we may try using a plug-in space heater in the office next winter (although the challenge will be to find one that’s reasonably energy-efficient while also remaining effective).

little ice build-up

Close up, showing very little ice present on the compressor itself.

 

 

Mitsubishi Wall-mounted Heads: Beauty or Beast

I’ve read that some interior designers, and even some homeowners, have expressed aesthetic concerns about the distribution heads. If you go on design-oriented websites like Houzz you can come across some really strong negative opinions on the topic.

family rm:kitchen hp head and zehnderFor us, they’ve never been a problem. Much like the Suntuitive glass on our west-facing windows, or even a dark or bright color on an interior accent wall, after a few days, like anything else, you just get used to it. I never found them to be ugly in the first place though.

MBR w: hp head and zehnder

I also grew up with hydronic metal baseboards for heat, while in apartments and our first home we had the typical floor supply and wall return grilles for a gas furnace — point being, the details of any HVAC system are never completely absent from any living space. There’s always something that shows up visually and, typically, that needs to be cleaned at some point.

In addition, the Zehnder ERV and the Mitsubishi heat pumps meant we didn’t have to utilize any framed soffits or duct chases (at least in the case of our specific floor plan) in order to hide bulky runs of traditional metal ductwork, typical in most homes when using a normal furnace. Unless designed with great care, these tend to be obtrusive, taking up premium ceiling, wall, or floor space. And if randomly placed simply for the convenience of the HVAC contractor, they can be downright ugly.

In other words, it doesn’t really matter if you’re building conventionally or if you’re building a Passive House, all the details of an HVAC system — whether it’s individual components, or even how these components will be placed inside a structure — should be carefully thought through (again, ideally before construction begins) to address any performance or aesthetic concerns.

 

 

Controlling and Adjusting the System

As far as the remote controls for the individual heads, we haven’t had any issues.

heat pump remote closed

For the most part, we set them to either heat or AC (roughly 70° and 74° respectively), and then forget about them.

heat pump remote open

To the extent I’ve looked through the manual, these seem straightforward, but again we haven’t really needed to do much in this regard. And when the weather is pleasant outdoors, we take every opportunity to turn off the system completely and then open windows.

Mike also explained the system could be combined with a Kumo cloud set-up, but we’ve been happy with just the hand-held remotes so far.

 

 

Routine Maintenance

And much like with the Zehnder ERV, I try to check the filters for the individual heads at least once a month (more like once a week when I was still doing interior finishes). Just as it takes much longer for the Zehnder filters to get dirty now that construction is over, the same has proven true for the blue filters in the Mitsubishi heads. It seems like about once a month is sufficient to keep up with the dust in the house.

Overall, we’ve been very happy with our HVAC set-up, including the Zehnder ERV and our Mitsubishi ductless mini split. As long as the units don’t have any durability issues, we should be happy with these systems for many years to come.

HVAC (Part 1 of 2): Zehnder ERV

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Building with Passive House principles in mind, we knew that, in addition to maintaining a tight building envelope, and incorporating substantial amounts of insulation around the structure, we also needed to install continuous mechanical ventilation in order to have adequate levels of fresh air, not to mention the ability to expel stale air.

We also needed our system, either an HRV or an ERV, to be highly efficient, meaning it could hold onto some of the heat in the conditioned air even as it introduced fresh and, oftentimes, cold air by means of heat exchange as the two streams of air (fresh and stale) passed by one another inside the main unit (without actually mixing together).

After researching the many options, we ended up going with Zehnder’s ERV, in our case, the ComfoAir 350 (the various Zehnder units are based on overall cfm demand of the structure).

We only considered two other brands for our mechanical ventilation (HRV vs. ERV):

UltimateAire

and

Renewaire

In all the research I did prior to construction, it was these three brands that showed up the most in the projects I read about.

Here’s a good debate on the Green Building Advisor website discussing brand options: ERV Choices

Another interesting option would be the CERV system. Because they’re a smaller, newer company, we didn’t feel comfortable pursuing it, but it does look like a viable option worth considering if building a Passive House or Pretty Good House.

I was also familiar with Panasonic units, but I had always read that they weren’t efficient enough in terms of the heat exchange function (or heat recovery) to seriously consider using it in a Passive House or a Pretty Good House in a predominantly cold climate region like ours here in the Chicago area.

Our Zehnder ComfoAir 350 is said to be 84% efficient in terms of heat recovery (the same principle applies in summer, only working in reverse, when you’re trying to hold onto cooled, conditioned air). Based on what I read during the design phase, the consensus seemed to be that, although more expensive, the Zehnder has a strong track record of performance and durability.

The Zehnder also came with its own ductwork, which we knew would simplify installation, allowing us to do it ourselves, rather than hire someone else to come in and run more conventional ductwork through the house (conventional ductwork would’ve taken up a lot more space as well). Even though the unit itself was more expensive, we thought we could offset some of the total cost for a ventilation system by installing the Zehnder ourselves, thereby saving some money on labor costs.

As far as the ERV/HRV debate for Northern US states, we decided to opt for the ERV because it was supposed to help us hold onto some humidity in winter months, especially important when most structures in the Chicago area are exceedingly dry for most of the winter (and our winters are long). Although I read repeatedly during the design stage that ERV’s can also help control summer outdoor humidity entering the house, this has not been our experience at all. In fact, the ERV seems pretty useless in this regard (more on this below).

The system quote we received was easy to understand, and Zehnder was nice enough to essentially design the system, both in terms of layout (i.e., where we should put all the supply and exhaust points), along with the quantity, or cfm’s, of air for each point. In the end, after commissioning the unit, the system should be balanced, meaning the unit should be bringing in as much fresh outdoor air as it is expelling stale indoor air.

As far as Zehnder units being DIY friendly in terms of installation, in our opinion, this is highly debatable since the installation manual is far from comprehensive. Our installation manual ended at physically installing the main unit on the wall. Not very helpful.

Without a detailed installation manual showing step-by-step how all the individual pieces fit together, you end up with a pile of what initially seems like random parts.

zehnder pile of parts

Everything we need to install our Zehnder ERV. Most of the smaller components are still in the many cardboard boxes off to the right.

This was incredibly frustrating, especially since Zehnder units are purchased at a premium when compared to other competitive brands, and with the expectation of durability and design precision. It never occurred to me to ask before purchasing the unit for an installation manual, since it seemed a fair assumption that no one would sell a premium product without detailed instructions on how to put it together.

We were only able to proceed because of numerous online videos, googling Zehnder unit photos, and by staring at and experimenting with the various parts to try and figure out how it all was supposed to come together. It was an unnecessary and torturous puzzle that shouldn’t have needed solving, and it wasted hours of my life that I’ll never get back. If you do an internet search and type in: “google review Zehnder America” the experience Sean Hoppes had with his installation wasn’t all that different from ours.

Looking on the current Zehnder website (February, 2019), I can’t find a more detailed set of instructions, either written or in a video format, which is disappointing. This seems like a pretty glaring oversight on Zehnder’s part, and one that should be remedied immediately.

Having lived with the unit for almost a year now, overall we’re happy with its performance, and we feel like we could install one fairly easily now that we’ve gone through the entire process, so it’s a shame we can’t say only nice things about the product simply because the installation manual was so limited or, more to the point, non-existent.

With each video and each photo, it was possible to glean one more crucial nugget of information, which took hours, whereas a detailed written manual or a step-by-step video would’ve made the process straightforward, and by comparison, frustration-free.

The videos below were especially helpful, but, nevertheless, they still leave out quite a bit of pertinent information necessary for any first-time installer (especially regarding all the parts that need to be installed on top of the main unit):

 

Unless there are no DIYers in Europe installing these units, and this is the expectation Zehnder has for its units both for overseas and here in the US, not having a comprehensive installation manual makes no sense. I’m not sure how even a licensed and competent HVAC installer would fare much better without direct experience installing the units. My guess is they would be searching online for missing info much like we did.

Once we got the main unit installed on the wall, and we figured out how all the parts fit together on top of the unit, by the time we got to installing the small, white 3″ ComfoTubes and the large, gray ComfoPipe, the process became much easier.

main unit attached to basement wall

Mounting the main unit to the basement foundation wall with Tapcon concrete screws.

In regards to the gray ComfoPipe for the main fresh air supply and the main exhaust, both of which pass through the wall assembly, we found it more effective to put individual sections together on the floor, and, once fully connected, we marked the points at which the pipes met with a permanent marker.

marking comfopipe w: sharpie

Marking sections of connected ComfoPipe with a Sharpie while they’re on the floor ensures a tight fit once a connection has been made off the floor.

If you try to piece the tubes together one piece at a time in mid-air it’s much harder to gauge when the pieces are actually tightly put together. With each connection point of pipe clearly marked with a Sharpie, it gives you an obvious goal to shoot for once you have the pipe almost in its final position. More to the point, it’s obvious when sections of pipe get out of alignment, or the connection isn’t nearly tight enough — it’s much more difficult to accurately gauge if only going by “feel” once the sections of ComfoPipe are off the floor.

drilling hole for Zehnder exhaust

Making initial cut in the Zip sheathing.

Using a piece of ComfoPipe, we outlined on the interior side of our Zip sheathing exactly where we wanted the pipe to end up (trying to get as close to center as possible — makes air sealing around any penetration much easier). After a hole was cut with a 3″ hole saw, we cut out the rest of the hole using a jigsaw.

hole in Zip for heat pump pvc

Hole cut and ready for the ComfoPipe.

 

hole set-up for comfopipe

Hole made in our Zip sheathing, ready for the ComfoPipe from outside to make a connection with the section inside.

 

ext - comfo pipe going thru zip into basement

Ready to push the ComfoPipe into the house from outside to make the connection inside.

 

Zehnder chipmunk's back

Chipmunks are back.

Once we started using the Sharpie, it was relatively easy to get all the ComfoPipe installed and air sealed around the Zip sheathing.

comfo pipe thru zip

Making the connection between inside and outside.

 

setting up comfo pipe

Adding a Roflex gasket to make air sealing much easier.

 

comfo pipe sealed int.

ComfoPipe air sealed on the interior side with Roflex gasket and Tescon Vana.

 

close up comfopipe sealed

Close up of the ComfoPipe air sealed at the Zip sheathing.

 

installing comfo pipe next to main unit

Finishing up the last sections of ComfoPipe as they leave the main unit.

Following the directions, we kept the ComfoPipe exit points for supply and exhaust more than 10′ apart outside, where they enter and exit the structure, in order to avoid any possibility of the two air streams mixing, which would undermine the effectiveness of the system.

comfopipe ext sealed and covered

Repeating the same air sealing process on the exterior for the ComfoPipe, adding black garbage bags over the opening with rubber bands to keep out dust, dirt, birds, and any critters that might otherwise try to enter the structure during construction.

On the outside, we made sure to extend the ComfoPipe out farther than we needed, giving us some leeway once insulation and siding were installed over the Zip sheathing. This allowed us to cut the ComfoPipe back to the proper depth before installing the permanent covers supplied by Zehnder.

comfo pipe ext close up sealed

Close up of ComfoPipe as it exits the structure (before insulation, furring strips, siding, and its final cover).

As far as the white tubing is concerned, we really enjoyed how easy it was to put the 3″ ComfoTubes together.

During the design phase, and even after we brought the Zehnder unit to the job site, we always intended to place the diffusers for supply and exhaust points on ceilings. But after really looking at all the cuts in our ceiling service chase that would be required to make this happen, we decided to opt for placing all of them on walls instead.

It proved to be one of the better decisions we made during construction. Not only did we avoid having to make many cuts in our ceiling structure, which would’ve meant a struggle to appropriately map them out around conduit, ceiling lights, and plumbing vents, it had the added benefit of making it much easier to do ongoing maintenance at the diffusers, mainly checking on and cleaning filters, once we moved in.

cone diffuser filter

Cone shaped filter for exhaust diffusers (bathrooms, kitchen, laundry room, and basement in our case).

In fact, during commissioning, our Zehnder rep told me they have issues with homeowners not keeping their exhaust diffuser filters properly cleaned, effectively undermining the efficiency and overall performance of the units. This is understandable if the diffusers are on ceilings, whether at 8′ or 9′. It would be easy to forget about them, or even if you did remember, one can understand the reluctance to drag out a 6′ step ladder every time they needed to be cleaned. We were also told that placement of the diffusers is extremely flexible — almost anywhere can work (check with Zehnder directly just to make sure your proposed placement will work).

inside diffuser filter

Diffuser filter in bathroom after about a month. Once all the construction dust settled down from completing interior finishes, these filters don’t get dirty nearly as quickly as they once did — in other words, this isn’t bad at all.

By keeping them around 7′ off the finished floor, it’s easy for me to check and clean the exhaust diffuser filters on a regular basis (1-2) times a month. I always have 2 sets of filters, so it’s easy to remove the dirty ones, put in clean ones, and then rinse and dry out the dirty ones.

Once we decided to go through walls (both 2×6 and 2×4 framed walls), it was just a matter of deciding where in each wall we wanted the diffusers to be placed, and then cutting the corresponding hole through the wall’s bottom plate and the subfloor — being careful to check, and re-check, in the basement for any floor joists, plumbing, or electric conduit that might be in the way.

For bathrooms we placed the diffusers between showers and toilets, slightly cheating towards the showers to ensure maximum moisture removal.

changa drilling for tubes

Apparently cutting the holes through the floor looked like fun, since my wife was happy to take over this chore for me. The DeWalt we were using worked great until it crapped out on us a couple of holes short of finishing. We definitely noticed a difference going back to a normal drill and hole saw set-up.

At the unit itself, Zehnder supplied us with blue (fresh air) and red (stale air) tags, to mark each ComfoTube as it leaves or returns to the main unit. This should make any potential maintenance or repair issues in the future easier to resolve, as well as helping to avoid confusion as you set in place each pipe at a diffuser.

first few return tubes are in

Attaching the white ComfoTubes to the main unit, carefully labeling each pipe for future reference.

 

main unit w: exhaust tubing installed

ComfoTubes being installed at the main unit.

 

top of silencers #2

Close up of the top of the main unit, as ComfoTubes are being installed.

 

Sydney helping us

Sydney, one of our former Excel students, was nice enough to stop by and help us pull the ComfoTubes from the basement up to the first floor.

 

OB helping us pull and set-up the tubes

OB was also nice enough to come back to help us push and pull the ComfoTubes into place for the diffusers.

 

spaghetti

Pulling more tubing than we need up to the first floor. Later it’s cut back to properly fit to the various diffuser boxes.

 

setting up a port

Putting together a diffuser box.

Since we’re leaving the basement ceiling unfinished, it’s an ideal place to see how all the components come together: ComfoTubes meet at the diffuser box, along with the final cover for the diffuser, in this case for supply air. As you can see in the photo, there’s plenty of room in the metal tube of the diffuser box for deciding exactly where to cut it off in order to establish the finished height for the diffuser cover. In the basement we left them at their full height since there didn’t seem to be much incentive to cut them back.

basement supply diffuser

Basement diffuser box with attached ComfoTubes and final diffuser head (supply in this case).

 

laundry rm zehnder

Exhaust point in utility room with only one ComfoTube.

All of the diffuser boxes required at least 2 ComfoTubes, except for the laundry/utility room, which only required one. Using one of the supplied black plastic caps made it easy to block off one of the outlets in the diffuser box. These black caps are also handy when pulling the ComfoTubes around into position since they help to keep out any construction debris.

laundry rm exhaust

One outlet in the diffuser box is blocked off for the laundry room since we only required 12cfm for this area (12cfm per opening/ComfoTube).

Our kitchen required the most cfm’s, at 36, so it required a special diffuser box and 3 ComfoTubes.

kitchen octopus

3-hole diffuser box (36 cfm) for kitchen exhaust.

Again, since we didn’t place it in the ceiling, we put it across the kitchen, basically on a diagonal from the stove. So far we haven’t had any issues with cooking grease or odors, and our range hood (recirculating) seems to be doing its job just as well.

sunlight coming down comfo tubes

Sunlight coming down the ComfoTubes into the basement from the main floor.

Using scrap lumber, we were able to give each diffuser its proper stability in the wall cavities. Although the mounting hardware for each diffuser box seems rather fragile, we managed to avoid any issues.

Applying a bit of hand soap around each opening in a diffuser box made getting a solid fit between the ComfoTube, the black O-ring, and the diffuser box fairly straightforward.

connecting tube in kitchen

Attaching ComfoTubes with black O-rings and sliding clips on the diffuser box.

 

tubes for octopus in kitchen

ComfoTubes for kitchen exhaust going through the subflooring and into the basement.

 

black 0 ring

Putting the black O-ring on the ComfoTube.

It was also fairly easy to get each ComfoTube exactly where we wanted it. Since they’re so small (at least compared to traditional sheet metal ductwork), the tubes are easy to manipulate and move around, whether over a basement beam, around plumbing, electric, or any other structural component that’s not easily relocated. As long as you don’t need to make a short 90° turn, the tubes are easy to work with, so I imagine they would be ideal for renovation work in older homes.

long shot before tightening comfo tubes

It was fairly easy to put the ComfoTubes exactly where we needed them to go.

With most of the ComfoTubes in place, we just needed to add a couple of walls in the basement before finishing up the last few ComfoTubes.

raising basement wall w: Jesus and Eduardo

Jesus and Eduardo were nice enough to come back to help me put up a couple of basement walls.

Once all the ComfoTubes were installed at all the diffusers and at the main unit in the basement, we were able to pull all the lines tighter for a less messy final installation.

spaghetti comfotubes

Before pulling the tubing tight.

Using 2×4’s, we created a little window for the ComfoTubes to pass through under the floor joists. This structure helped to get the ComfoTubes moving away from the main unit in an orderly way that made it much easier to organize all the tubing once it was all installed.

zehnder installed w: tubes

All the ComfoTubes pulled tight, up by the floor joists, kept in place with some plumbing hangers.

Using plumbing hangers also kept the ComfoTubes under control and organized.

hanger straps for comfo tubes

Straps used to corral the sometimes unwieldy ComfoTubes, which can resemble spaghetti if left unorganized. They also worked well at stabilizing the gray ComfoPipe.

The commissioning of the unit, after drywall was complete, was fairly easy and straightforward, apart from a couple of wiring and electrical issues that had to be dealt with by phone with a Zehnder rep beforehand. And ordering filters from the Zehnder website has also been a straightforward and painless process so far (they’re not cheap, but they do seem to be highly effective).

The only issue we’ve really noticed with the unit is during summer when outdoor humidity levels are high. Since the ERV is constantly running, there’s no way to avoid bringing in some humid air in the summer.

And, unfortunately, it’s enough so that our Mitsubishi heat pump set-up (a future Part 2 of 2 for HVAC details) can’t properly get rid of the excess humidity either, even as it keeps the interior more than adequately cooled. We tried setting the heads to dehumidify, but they just dropped the temperature (almost to 60° F) without budging the humidity in the house very much — the rooms were freezing and clammy. As noted earlier, an ERV just can’t handle elevated levels of humidity in the summer on its own.

By having meters in various areas of the house it’s easy to see when humidity levels become a problem (we’ve been happy with our AcuRite gauges). Last summer our solution was to buy a couple of small dehumidifies, one for the first floor and one for the basement. They worked, but they also ate up a lot of energy. Setting the Zehnder fan speed to LOW seemed to help somewhat, but not enough to avoid using the dehumidifiers. This summer we’re going to try a stand-alone Ultra-Aire whole-house dehumidifier, which should use less electricity, and it should perform at least as well, if not better, at removing excess humidity.

 

Having read that anything above 60% indoor humidity can be problematic, especially in tighter, high-performance homes, it was disheartening to see the numbers move towards 70% in early summer. This is what prompted the purchase of the dehumidifiers.

From everything I had read during the design phase regarding Passive House, I knew indoor humidity in the summer could be a slight issue, but having experienced it firsthand, it now seems obvious that incorporating a dedicated dehumidifier in any structure that will see elevated levels of summer humidity, even if it’s only expected to last for just a few weeks, is simply a necessity. Based on what I’ve read recently, it sounds like Passive House designers, who were already doing this for Southern US states, are moving towards doing it in states much farther north. Presumably this would also hold true for anyone designing a Pretty Good House as well.

Granted, 60-70% indoor humidity (or even higher) for a couple of weeks probably won’t ruin any structure, but for us, at least, keeping it in the 50-60% range during the hottest days of summer not only gives us some added peace of mind, regardless of the hit we’ll take in terms of overall energy use, but it’s also an issue of comfort (I grew up in a house without air conditioning and still have vivid memories —all of them bad — of enduring hot and humid summer days and, even worse, long summer nights).

Much like the initial complaints of overheating, due to excessive or improper placement of glazing, especially on southern facades, this issue with excessive humidity seems to be part of the evolution in understanding how Passive Houses, or high-performance homes generally, actually work in real-world conditions. Although the concept has been around since the 1990’s, anyone building to or even just towards the Passive House standard should know they are guinea pigs to some extent, no matter how well established the idea may be in building science terms.

In the winter, we’ve had no issues. When temperatures fall below 20° F, we set the Zehnder to LOW, in the hopes that it will reduce demand on the heat pumps slightly, and it seems to hold onto humidity somewhat when the cold air being introduced would otherwise be excessively dry. Indoor humidity levels have been pretty consistent: above freezing they typically stay around 40%, and when temperatures plummet towards zero or below they’ve still stayed in the 30-35% range. We’ve rarely seen indoor humidity drop below 30%, even on the coldest days, which definitely makes a difference on overall comfort levels. I’ve also noticed that wood flooring and wood trim doesn’t shrink nearly as much as it did in our last, conventionally built home.

Also, even when we experienced record low temperatures last month (January, 2019), hitting -24° F without windchill, the Zehnder kept on running without any issues. As far as we know, it never shut off to try and protect itself from the cold (our mini-split system did, but more on that later). The product literature is somewhat vague, only noting that low temperatures could cause a unit to shut off, but it’s unclear at exactly what temperatures or what combination of other environmental conditions might cause this to happen.

Most people either tape or use sealant on the gray ComfoPipe seams to block air leakage. During our blower door test no air leakage showed up, even with a smoke pen test. Nevertheless, during our recent cold snap some frost was evident on the ComfoPipe seams, so I’ll eventually caulk these seams with Pro Clima’s HF Sealant, since there must be some air leakage, be it ever so minor.

In terms of the boost function, when turned on it pulls from all the exhaust diffusers, not just a particular bathroom or the kitchen. Again, for the kitchen, even if we’ve been roasting garlic or cooking something else that’s equally pungent, by the next morning any cooking smell is usually completely gone. There’s never been any lingering smells emanating from the kitchen.

For the kitchen, when you want to utilize the boost function you just set the ComfoSense wall unit to HIGH (the Zehnder equivalent to a standard wall thermostat). Unlike the bathroom boost switches, which run on a timer (set at the main unit in the basement), when you’re done cooking you have to remember to go back and lower the fan speed, otherwise it just stays on HIGH.

The ComfoSense unit also can display error functions or tell you when filters at the unit need to be cleaned. It also has an AWAY function, meaning you can have minimal fan speed to exchange air while you’re on vacation instead of just unplugging the unit altogether.

 

boost rocker switch

Boost rocker switch in the bathroom.

The boost switch in a bathroom is set to run for 30 minutes on the highest fan speed. So far, this seems to be plenty of time for it to work properly. Unlike a normal bath fan, which tends to be quite loud, even when the Zehnder is in boost mode it’s still incredibly quiet, so guests need to know they only need to press the switch once — it is indeed working.

For the bathrooms, the boost function has been working really well at removing moisture after showers. Nevertheless, in the winter, when temperatures are below 20° F and we decline to use the boost function after showers (again, hoping to hold onto some of the added humidity), the bathroom humidity levels still quickly drop from the 60’s and 70’s back to the mid-30’s in less than an hour (and this is even when the Zehnder fan speed is set to LOW).

We’ve also been happy with the diffusers, in terms of installing/removing them when necessary, but also in terms of their overall look. Whether on more neutral colored walls, or something bolder, they just look nice in our opinion.

supply diffuser

Zehnder supply diffuser on a neutral background on the wall.

They’re subtle enough to blend in to the background, but attractive enough so when they are noticed they don’t stand out in a negative way.

Zehnder exhaust diffuser

Utility room with a Zehnder exhaust diffuser on a neutral background — around the corner from the clothes dryer.

 

diffuser w: bold colors in bg

Zehnder supply diffuser on a much bolder background.

As far as changing filters at the unit, or even cleaning the core itself, so far it’s been a trouble-free experience.

Here’s a photo of a supply-side filter after one month of exposure in winter:

zehnder supply filter

A Zehnder supply-side filter (MERV 13) after 1 month in winter.

During the summer, of course, they look much worse after a month with so much more “stuff” floating around (pollen, debris from landscaping, insects, etc.). Also unsurprisingly, the exhaust-side filter always takes much longer to get dirty as stale air makes its way out of the structure (it probably helps that we don’t have any cats or dogs).

And since we didn’t need the framed-out HVAC chase in the corner of our Master Bath for all the ComfoTubes that we initially planned to send up into our ceilings, we ended up using this area for some much needed niche shelving for various toiletries and even some towels.

Overall, then, we’ve been extremely happy with our Zehnder ERV unit.

 

Windows and Doors (Air Sealing #8)

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Window Options For a Passive House, or a Pretty Good House

Even in 2017, when the majority of our build was completed, the number of Passive House quality window and door options was increasing. Today, in 2018, they’ve only continued to grow.

For example, here is an article from the Green Building Advisor website from June, 2018 discussing high-performance window options: What Windows Should I Buy?

In addition, 475 High Performance Building Supply is selling an Austrian high-performance window, Bewiso:

A New Jersey Passive House builder, Darren Macri, has created his own product line: Wythe Windows

And GO Logic is an importer of a German brand: Kneer Sud Fenstern und Turen

They have an old blog post on their site discussing their history with the brand: GO Logic

There are also some custom, small-scale, American-made options as well:

Hammer and Hand

HH Windows

They share similar characteristics, including insulated triple pane glass, thermally broken sashes and frames, multi-point locking systems for airtight seals against gaskets on the frames, the European-style tilt-turn function, and the seemingly ubiquitous but beautiful Roto hardware.

It’s nice to see that more options are becoming available to those looking for high-performance windows in the US — hopefully this means a long-term movement towards better overall building standards in terms of quality, durability, and performance.

And here’s a quick overview on high-performance builds and the need for quality windows and doors: Hammer and Hand

Although not everyone is entirely convinced, and there’s still debate regarding exactly what’s “necessary” in terms of performance (the exception would be building to the Passive House standard, either PHIUS or PHI, where the requirements are more black and white). There’s a lot more latitude if building a Pretty Good House, or the homeowner is only looking to meet the benchmark of Net Zero.

 

 

Suntuitive Dynamic Glass for Our West-Facing Windows

When my wife’s cousin found out we were trying to build a high-performance new home (a mix of Passive House and Pretty Good House), he suggested we incorporate his company’s self-tinting glass. Used largely in commercial applications since its introduction, the product is beginning to make inroads into the residential market as the cost comes down: Suntuitive

For anyone near the northwest suburbs of Chicago, you can see the glass in person at the Ziegler Maserati dealership in Schaumburg, Illinois: Exterior View

As the product has continued to evolve, they’ve been able to remove much of the “green” look to the glass. This is evident in the Ziegler dealership glass, but even in that application I didn’t think that it was all that prominent. The overall look of the glass was still impressive.

As to function, the Suntuitive coating between the layers of glass adjusts its level of tint based on the temperature of an inner layer. In the summer, this has obvious benefits when high temperatures combine with glaring sun to enter a structure, particularly in the east in the morning or the west in the afternoon (even to the south without some protection with overhangs). But the really nice thing about the product is that it doesn’t tint on the coldest days in winter, allowing for some solar heat gain and natural daylight exactly when you want it most on sunny, wintry days.

For energy reasons, and also personal aesthetic choices, we decided to forego any windows on the east side of our house. Instead, we just have our front door facing the street (it has a limited amount of privacy glass to let in some morning light). On the other hand, because we wanted to use a significant amount of glass on the west side, which faces our backyard, and we knew overhangs couldn’t offer much relief from the summer afternoon sun, Suntuitive was a great solution for us — especially since we wanted to avoid using blinds or curtains as much as possible.

Following Passive House principles for glazing, we wanted to optimize our views and connection to the outside through our limited and strategically placed number of windows.

Here’s a useful video showing the effects the sun can have on a structure in various seasons:

And here’s an interesting video discussing the challenges associated with managing both solar orientation and scenic views when they’re in conflict:

For our house, we only have a single window to the north (for my daughter’s bedroom), while the majority of our windows are on the south side, where we spend most of our time in the living spaces (open kitchen and family room). In effect, we’ve limited our windows in private areas of the house, mainly two bathrooms. Besides energy concerns, we didn’t think it made sense to add additional glass to our north, mainly because our neighbor’s house blocks any meaningful views while also reducing privacy.

Additionally, we have a significant overhang on the south side, which allows us to block out most of the summer sun while allowing in plenty of winter sun for passive solar heating during our coldest months, so the windows on the southern facade easily take care of most of our daylighting needs.

By utilizing the Suntuitive glass on only the west-facing windows (family room and master bedroom) it allows us to maintain our open view of the backyard while avoiding migraine-inducing summer afternoon sun.

Here are the specs for the particular glass we chose to use (they have a wide variety of options, including color variations): Vertical CrystalGray Triple Glaze Performance Sheet – Lee-Whetzel

Although we lose some potential solar heat gain through these windows in winter (compared to the glass in a typical Passive House certified window), we feel it’s more than compensated for by the blocking of hot, bright summer afternoon sun.

Here’s a company video describing the Suntuitive product in real world applications:

 

 

Unilux Windows and Doors

My wife’s cousin suggested a couple of options for the Suntuitive glass: Kolbe Windows or Unilux Windows.

We went to see the Kolbe windows in a local showroom, but they didn’t seem impressive. It also didn’t help that the salesperson was dismissive of the product, suggesting that if we were considering Kolbe we should just use Marvin instead (another brand they sold). The salesperson literally had to wander around looking for a sample unit, eventually finding one buried in a corner. We’re not even sure if what we saw represented the full breadth of the Kolbe product line.

At any rate, since Unilux was willing to work with the Suntuitive glazing, it made it easy to go with them rather than trying to convince another Passive House certified window maker that Suntuitive could be compatible with their product line.

[Note: Suntuitive is constantly adding new manufacturers willing to work with their product, so contact them directly if you have a specific brand you’d like to use on your own project.]

After deciding to go with the Unilux windows and doors, we ended up with the following specs:

[Please note: The numbers below were mostly supplied to me by my Unilux window rep. Following up with a Unilux rep on the East Cost, Scott Gibson, from Green Building Advisor, received different information. If you’re contemplating using Unilux, contact your local rep or the company directly in Germany for written confirmation regarding performance numbers — especially if you’re running data through a program like PHPP.]

Main Floor Windows (excludes west-facing windows with Suntuitive):

  • Interior wood with aluminum-clad exteriors
  • Glass: Unilux Super-Thermo 3
    • Triple pane with a reported R-ll center of glass
      • R-8 for whole window once frames are included
  • U-factor of 0.18
  • SHGC of 0.53

2-Basement Windows:

  • Isostar: interior uPVC with exterior aluminum-clad
  • The same glass as the main floor windows.

Two doors:

  • One for our front entry, and one for our kitchen. They both have the R-11 center of glass glazing, with the kitchen door having a significant amount of privacy glass (it faces south), which is really enjoyable on cold days with the sun shining.

We chose PVC for the basement windows to save some money, but also because we thought the natural wood finish on a basement window might look out of place — we’re painting the concrete foundation walls, and partially drywalling an office area, but otherwise we’re  leaving the basement unfinished (it will look finished for our tastes at any rate).

The total cost for the windows and doors was just over $26,000 (including the Suntuitive for the windows facing west), with the two doors representing almost $10,000 of this total.

In regards to the Suntuitive glass, it is currently selling for roughly $31/sq. ft., depending on specific application requirements. You can contact my wife’s cousin, Dan, at his email address if you have technical questions, or if you’d like to get a quote for your own project: leed@pleotint.com

I don’t believe the Unilux windows and doors are technically certified by PHIUS or PHI, but their performance metrics are close to the necessary requirements, so we were comfortable using them, especially since we had no intention of pursuing official Passive House certification anyway.

 

 

Window Bucks

After firing our two GC’s in February, 2017, we lost a few weeks as we scrambled to cut ties with them while simultaneously lining up new subcontractors to keep the project moving forward.

Once things were back on track, I was able to begin installing the window and door bucks in preparation for the delivery of the eventual windows and doors.

Using 3/4″ CDX exterior plywood, I installed the bucks so they would extend out far enough to meet up with our eventual two layers of 2″ Rockwool Comfortboard 80 and two layers of furring strips for our ventilated rainscreen (vertical and horizontal since most of our charred cedar siding would be oriented vertically).

Here’s how a similar set-up looked on Hammer and Hand’s Madrona House project:

We decided to go with “innie” windows, so our windows would be placed near the center of our wall assembly to optimize their energy performance. Placing windows near the center of the wall assembly also creates nice shadow lines on the structure throughout the day. Overall, we just really like the way recessed windows look on a house.

Prior to construction, I created a mock wall assembly with a window buck, which proved to be good practice for building the real thing.

mock-wall-assembly-w-sealant-in-sun

Mock-up of the wall assembly put together before construction began.

Mock wall assembly after practicing with the tapes:

mock-wall-assembly-w-tapes

This mock wall assembly gave me the chance to practice applying these tapes before doing it for real on the house.

It’s also worth mentioning that it’s important with these tapes to make sure that once applied you go over them, applying pressure, to ensure the adhesive is properly activated. 475 HPBS always included at least one of their blue Pressfix tools in each box of tape that I ordered. The tool is roughly similar to a bondo spreader.

pro-clima-pressfix.jpg

Pressfix after heavy use.

We were following many of the details in Hammer and Hand’s Madrona House project:

I watched their videos dozens of times, especially this one, trying to make sure I got all of the details right. Their Best Practices Manual was also invaluable as I kept referring to it throughout the duration of the build (an incredible gift to contractors and self-builders alike who are tackling a high-performance build for the first time).

Once each buck was installed, I went around and used HF Sealant to seal all the gaps, seams, and screw holes in the window and door bucks.

BR #2 window buck with HF sealant

First window buck installed.

Here’s a close-up of the same window as the HF sealant is being applied:

close up of BR #2 with HF sealant

HF Sealant at the transition between the Zip sheathing and the window buck.

And here’s a different buck being sealed on the interior surfaces.

lwr rgt int wdw buck w: hf sealant

Using HF sealant to seal seams, imperfections, and screw holes in the plywood window bucks.

Another view of the buck being sealed up with the HF sealant:

int wdw buck w: hf sealant

With the bucks installed, I could then begin applying the various air sealing tapes to all the surfaces of the bucks. I decided to use the Pro Clima line of products, available from 475 HPBS, after ordering them and using them to create my mock wall assembly.

The other option would’ve been to use the Siga brand of air sealing tapes, available from Small Planet Supply, or the black Huber Zip sheathing tape.

Although clearly based on my own personal prejudice rather than scientific evidence, I was reluctant to use the Zip tape, 3M tape, or something similar, mainly because I knew the European brands have a much longer track record of success.

Yet another option would’ve been to use liquid applied membranes (e.g., Prosoco, again Zip, or others), which I’ll address later, when noting the details for sealing up my front door buck area.

Knowing that corners and other areas where elements meet up could be problematic for proper air sealing, as pointed out by Sam Hagerman in this Hammer and Hand video,

I started by addressing some of these areas first.

For example, here’s the lower right of a window buck where it meets the Zip sheathing:lowr rgt buck 1st profil at zip

By building up the corners in this way I was hoping to guarantee complete coverage against air and water infiltration at these tricky points.

lower rgt buck w: profil at zip

Same area with overlapping top layer.

Here’s the top of the buck where it meets up with the Zip sheathing:

profil on buck meeting zip

Corner where the buck meets the Zip protected again with 2 separate overlapping pieces of tape.

The Profil tape, which splits into thirds on the back, makes corners much easier to tackle.

After using the Tescon Vana in the upper inside corner of the buck, I used the Profil tape to address the upper outside corners of the bucks.

int buck w: tvana and 1st profil

Tescon Vana, then Profil for this upper outside corner.

Here’s two views of the second top piece for this area:

outside upper rgt w: profil

Putting it in place before making a small cut to fold over the outside edge.

Here’s another view of the same area, this time looking at the buck head-on:

upper rgt of wdw buck w: profil

Same area after cutting the piece and ready to fold it down into position.

By making small cuts in the Profil tape with a razor blade, corners are easy to shape to the form you need. Although making a cut while the tape is already in position is relatively easy to do, avoiding any damage to underlying layers is obviously very important. For this reason, it’s probably safer to make cuts before getting the tape into position.

For instance, an initial cut in the Profil tape:

cutting profil for corner

And then making a fold to establish the basic shape for an outside corner:

cut folded profil for outside corner

Once you initially set the tape in its position, gently remove the white backing paper, trying to avoid moving the tape too much, which would change its position or cause wrinkles.

I didn’t use the Profil tape for the two lower outside corners since these areas would eventually get throughly covered by the Extoseal Encors sill pan tape.

Once the corners were taped up, I moved on to the bottom of the buck, using the black Contega Solido Exo tape.

First piece of Contega being applied to the bottom of a buck where it meets the Zip sheathing:

contega lower lft corner

The same area once the piece of Contega is cut to allow it to partially wrap up the side of the buck.

contega under and up side

First piece of Contega being installed.

Note the white paper backing that helps to position the Contega exactly where you need it, while also reducing the chances for wrinkles to form (an area for potential air leaks).

The Contega, like the light blue Profil, comes with a 3-part split backing. Although this 3-part backing helps a lot, I still struggled at times to avoid wrinkles with the Contega. The Contega is noticeably thinner than the blue Tescon Vana, which is probably why I found the Tescon Vana much easier to use. In fact, if I had it to do over, I would just use a wider version of the Tescon Vana to replace the Contega.

The nice thing about the wider versions of the Tescon Vana is it also comes with a split back for ease of placement.

tescon vana 6 w: split backing

6″ Tescon Vana with split backing.

Once an initial piece of Tescon Vana (3″) covered the exposed front outside edge of the plywood, I applied the wider Tescon Vana (6″), before applying the Contega to the Zip – buck – bottom piece of Contega connection, effectively bringing these adjoining areas together.

starting contega up lft sde buck

Second piece of Contega going up the side of the window buck.

Getting the first third of the Contega attached to the Zip before removing the remaining 2 strips of white paper backing seemed to help get it to sit flat without too many wrinkles.

contega up lft sde of buck pulling strip

Removing the smallest of the 3 strips of white paper backing.

The Contega was then cut so that it lapped the first piece of Contega on the bottom of the window buck.

And here is the Contega as it ends up on the top of the window buck.

close up contega up over top of buck

Corners being covered multiple times: HF sealant, Profil tape, and then Contega tape.

Making progress across the top of the window buck, building up the layers in shingle fashion, first with the Tescon Vana on the exposed front edge of the plywood, then moving up with the Contega, before finishing with a final strip of Tescon Vana on the Zip sheathing.

progressing across top of buck

Moving across the top of the window buck.

Top of the window buck almost complete:

upper lft buck w: top pce of contega

Same area finished off with a strip of Tescon Vana:

head of wdw buck finished w: t vana

Here’s a side view of a completed window buck. Note the sloped top, achieved with a piece of beveled cedar siding. Hopefully water won’t make its way to this area above each window or door (it’ll have to get past 4″ of Rockwool), but the slope that’s present will hopefully encourage any water that does so to harmlessly drip off rather than hang around to cause potential damage.

prepped wdw buck w: sloped top

Once the exterior of the window bucks were complete, I went inside to cover the interior head and legs of each buck.

contega interior of buck

Contega on the top and sides of the interior of each buck.

Here’s a Siga video I only recently came across, showing another way to deal with corners:

The last area to be addressed was the window sills. For this area I used the Extoseal Encors product. It’s vapor-closed, highly pliable, but also thick to prevent any water that ends up on the sill from entering the structure.

I really enjoyed using the Extoseal Encors, although you do need to avoid thinning it out as you wrap it around outside corners.

The only time I had a problem with it was on my last window buck. Temperatures were rising and I was working in direct sunlight. It was only in the high 60’s, but that was enough to cause some bubbling in the material.

extoseal bubble in sun

Some bubbles caused by working in the sun.

In my experience, the Extoseal Encors performed at its best the colder it was outside.

window buck almost complete

After a second row of overlapping Extoseal Encors on the sill to the interior, this window buck would be complete.

 

 

Door Bucks

Once the window bucks were installed, I could move on to the two door bucks (front entry and side kitchen entry).

legs of kitch buck installed

Installing the door buck for the side, kitchen door.

Plywood portion of the door buck complete with bottom piece installed:

kitch dr buck looking down at plywood

Looking down on completed plywood door buck.

Note the small voids in the plywood pictured below. Because of gaps like these, I chose to cover the edge grain of all the plywood window and door bucks with the HF sealant before applying tapes, just to ensure no air could migrate through the layers of plywood.

lwr rgt door buck w: plywood

Outside corner of door buck.

After completing the plywood door buck, it was time to give it support from underneath. Although about 2/3 of the door would rest on the subfloor/floor joists, leaving that remaining 1/3 unsupported made me nervous.

While there’s plenty of information available regarding the use of window bucks, I found surprisingly little regarding the installation and weather-proofing of door bucks. I couldn’t find any information for this detail in my Passive House books, or any description of it online, so I consulted with a local GC to come up with a solution.

As an aside, Rick, from Cypress Builders in Palatine, Illinois, proved to be an invaluable resource for a whole host of design problems and issues during our build. After firing our two GC’s, he was kind enough to take on the role of building consultant: Every couple of weeks I would come up with a list of questions, and he would stop by the job site to run through answers and possible solutions.

To his credit, the level of detail involved in a Passive House build didn’t scare him off — it did for many of the other GC’s, carpenters, and siding companies I had out to the job site for estimates — none more blunt than one particular carpenter who could only shake his head over and over as I went through the components of our wall assembly before finally blurting out in frustration: “Why the fuck would anybody build this way”. It’s funny now, but it wasn’t at the time when I was struggling to line up subcontractors to try and finish the project.

Rick was incredibly generous with his time, knowledge, and experience — it’s no overstatement to say it’s doubtful we would’ve completed our build without him. His decades in the building industry allowed him to offer sage advice, and I always ended up calmer and more confident about completing the next stage of the build after each of his site visits. I would definitely recommend him to anyone in the Chicago suburbs looking to build or remodel (the mix of experience, honesty, and excellent communication skills is hard to find).

And for any other DIY self-builds, I can’t recommend strongly enough how important it is to seek out a similar mentor for your own project. Even if things are going well, whether in the design stage or even the actual build, it can’t hurt to have a construction veteran stop by and try to spot problems, or potential problems. A second set of eyes, eyes that have seen decades of construction acumen along with plenty of stupidity, can only improve the quality of your own build. As invaluable as online resources like GBA, BSC, and Hammer and Hand have been to our build, none of those resources could visit our job site directly, so someone like Rick helped to complete the circle of advice and knowledge that can make the difference between a successful build and total disaster.

To try and give the door buck structural support, I first installed a layer of Rockwool against the green Zip sheathing directly underneath the door buck, attaching it initially with some construction adhesive. I was hoping this would act like the foam in an insulated header.

rockwool for under door buck

Prepping the Rockwool for the door buck.

After the Rockwool (2″ Comfortboard 80), I attached two 2×8’s with eight Headlok screws through the Zip, rim joist, and some of the floor joists as well.

We would eventually use these screws extensively to attach our first layer of furring strips through two layers of 2″ Rockwool Comfortboard 80 and our Zip sheathing (again, more on this later). I also used their 4 1/2″ screw to correct a couple of window headers that were out of square. With the spider drive, they work incredibly well.

Unfortunately, when installing the two 2×8’s I accidentally compressed the Rockwool slightly, requiring a final layer of 1/4″ plywood. Thankfully I was able to avoid compressing the Rockwool for my front door buck, so the 1/4″ plywood wasn’t necessary.

kitch buck w: 1:4 plywood

Layers of support underneath the door buck. The Rockwool is intended to act as a thermal break, much like foam in an insulated header.

Another view of the door buck with basic components installed:

kitch buck w: plywood installed

Note the visible gap between the bottom of the buck and the Rockwool on the foundation below. This gap was closed with additional pieces of Rockwool cut to fit.

Because of the Rockwool, sealing the end grain of the 2×8’s would’ve been difficult with only the tapes, so I first applied the HF Sealant to try and create a monolithic surface:

Side Door - built out w: sealant

HF Sealant covering the Rockwool and the end grain of the 2×8’s. Additional Roxul installed between the buck and the Roxul on the exterior of our foundation to close this gap.

If I had it to do over, I’d use Prosoco’s Fast Flash since, unlike the HF Sealant, it’s vapor open, so probably a better long-term solution should moisture of any kind find its way to this area. Once the HF Sealant was dry, it was straightforward to apply the Extoseal Encors.

But before applying the Extoseal Encors, I applied the tapes in the same pattern and manner as I did for all the window bucks.

I also added additional layers of Rockwool and a final layer of pink rigid foam to bring everything out to the same plane before installing the Extoseal Encors.

taping side of door buck - south side

Applying the tapes to the kitchen door buck.

 

lwr rigt kitch buck w: foam and extoseal

Extoseal Encors across the  bottom face of the door buck.

Also, in addition to the Extoseal Encors across the face of the pink foam, the concrete sub later applied a layer of EPDM rubber to try and prevent moisture intrusion/damage in this area.

lwr lft kitch dr buck w: first row extoseal

Second row of Extoseal Encors, wrapping down over the first.

Although the Extoseal Encors looks great when it first goes on, once temperatures rise it becomes gooey in the sun, so it was a challenge to maintain its integrity before the door went in. If I could do it over, I would hold off on installing the Extoseal Encors until the day before, or the morning of, the door’s installation.

lower lft kitch dr buck w: extoseal

From outside, looking down on the bottom left corner of the door buck: last piece of Extoseal Encors installed.

From outside, a close-up of the right outside corner of the door buck:

lower rgt kitch dr buck w: extoseal

Extoseal Encors wrapped around the outside corner of our kitchen door buck.

And a view of the completed door buck:

kitch door buck w: extoseal installed

Ready for the kitchen door.

For the front entry door buck I repeated the same assembly of components (minus the 1/4″ plywood and pink rigid foam), the only major change a switch to Prosoco’s R-Guard series of products; namely their Joint and Seam and Fast Flash, replacing the Pro Clima tapes and HF Sealant.

Before the start of construction, I intended to use the Prosoco products for all the air and water sealing details, but when it looked like construction would happen in the winter of 2016-17 I knew I had to change to tapes since most of them can be applied below 20° F (this includes the HF sealant), while the R-Guard series of products can only be applied in above-freezing temperatures (you’ll want to contact the manufacturers for exact installation directions and requirements).

Since it was August by the time I did the front door buck, I decided to try the Prosoco products just so I could compare them to the European-style tapes I had been using. I was able to find the R-Guard series of products online at World Class Supply.

frt dr buck looking down j and seam

Lower left corner of front door buck. Pink Joint and Seam on the bottom, red Fast Flash running up the leg of the door buck.

Exterior head and legs of the door buck covered in Joint and Seam and Fast Flash:

lft ext side of frt dr buck w: fast flash

Upper right corner of the front door buck after applying Joint and Seam and Fast Flash:

upper rgt frt dr buck w: fast flash

Lower left outside view of the front door buck after Rockwool, 2-2×8’s, Joint and Seam, and Fast Flash have been installed and applied:

front door lower left w: fast flash

There were a few gaps between the Rockwool and other components around the house where the Joint and Seam seemed to work surprisingly well as a sealant. Even though the Rockwool is fibrous, the Joint and Seam was still able to stick tenaciously — hopefully it continues to work in the long-term.

And here’s a couple more pics of the completed door buck, ready for the front door:

front door entry low shot of fast flash

Completed bottom section of front entry door buck.

Standing indoors, looking down at the right corner of the front entry door buck:

front door entry w: fast flash

Fast Flash around the perimeter of the front door buck.

As things turned out, this front door buck would end up exposed to construction foot traffic and the elements for about 4 months. Having a cheap, temporary front door helped to keep most of the rain out, but even so, the Fast Flash held up surprisingly well. Apart from a couple of tiny touch-ups with additional Fast Flash just prior to the front door being installed, there was little damage to the membrane.

And once the house was done, most people when entering or exiting skip the metal flashing and the door’s threshold (the area I was trying to give added support), preferring to step directly from the concrete stoop into the house and onto the tile since it feels more natural, but it’s nice to know that if these areas ever do see serious weight (e.g., moving heavy appliances or furniture) that it’s fully supported.

Just recently I had time to look through William Maclay’s book The New Net Zero, a fantastic resource I would’ve loved to have before and during our build, and I noticed in a diagram on page 343 the use of a (4″ x 4″) piece of fiberglass angle: “… fasten to rim joist to support extension of floor at door opening”.

If I could do it over, I would use the fiberglass angle instead of the 2-2×8’s. Last winter we had a cold spell for about two weeks where temperatures stayed in single digits, and although I checked behind my Rockwool in the basement just below my two door openings at the rim joists for any signs of moisture issues and found nothing (luckily), the fiberglass angle seems like a much simpler solution since it’s thermally broken and much smaller than my 2-2×8’s, which would’ve meant I could’ve almost completely insulated below the door bucks while also giving this area plenty of long-term structural support.

Of course, consulting a structural engineer or architect wouldn’t hurt either, just to establish exactly what’s required for tackling this area.

For anyone who’s interested, I found the following suppliers for fiberglass angle online:

Grainger

Strongwell

 

 

Air Sealing Products: Tapes or Liquid Membranes?

In regards to air sealing, I was really impressed with the Pro Clima series of tapes and their HF Sealant. I was equally impressed with the Prosoco R-Guard series of products (Joint and Seam, Fast Flash, and Air Dam).

Because I found the Prosoco series of products slightly easier to use since they’re less fussy to apply, I would choose tapes or liquid membranes based on the weather conditions of the job site: If it’s going to be too cold to use the Prosoco, then I would use the tapes (and the HF Sealant). Otherwise, I’d probably stick to the liquid membranes. I’m guessing the choice typically comes down to personal preference of the installers (apart from weather restrictions), or what the architect specifies on the drawings.

Here are some videos showing various liquid membranes in action:

And there are now other copy cat products available:

And 475 HPBS and Pro Clima now offer their own version of a liquid applied membrane:

VISCONN

 

 

Completing Air and Water Sealing of the Windows and Doors (Interior)

Our Unilux sales rep was nice enough to arrange for Bob Riggs and his crew to come down from Wisconsin to install all of our windows and doors. After firing our two GC’s, we really didn’t know who to use for the install. Not many contractors in the Chicago area have experience with these type of windows and doors, so it was hardly straightforward to find someone.

We had ordered our windows in September, 2016, we had fired our GC’s in February, 2017, and we were finally able to install our windows June, 2017. It had been a long wait, so we were excited and nervous to watch them go in. Familiar with Germany’s reputation for engineering excellence, it was one of the more exciting aspects of the build.

guys putting in kitchen window

Kellum, Tony, Bob Riggs, and his son Brian placing our kitchen window frame.

Bob and his crew did a great job for us. We’re lucky and extremely thankful that they were willing to come down to help us out of a jam. And the guys they used from JPK Builders to help them with the install were also extremely professional (more on this in a moment) and easy to work with.

As far as installation details, for the most part the guys followed the steps outlined in this Hammer and Hand video, only changing the Tremco illbruck tape for Hannoband 3E tape:

I chose to go with the Hannoband 3E tape, but there are any number of options for air and water sealing around windows and doors:

Here’s a video detailing the use of the Hannoband 3E black expanding foam tape, which I purchased from Small Planet Supply:

The Hannoband tape has some nice characteristics, such as adding some R-value to the gap, it’s water and air tight, but it’s also vapor-open. It’s also easy to work with and install, it performs really well, and using it means not having to fill the gap between window and framing with canned spray foam (prone to failure according to some Passive House designers and builders). Overall, it just seems like an elegant solution for air and water sealing what can otherwise be a difficult gap to deal with.

Here’s a short video from Tremco showing how these expanding black foam tapes work:

And here’s a photo of the Hannoband 3E, dramatically showing just how much expansion it is capable of if left unimpeded:

Hannoband 3E showing expansion

On the left, Hannoband just cut from the roll of foam tape. On the right, Hannoband after 48 hours of unimpeded expansion.

It also comes in different sizes to better match the gap that needs filling.

The photo below was taken shortly after installation, before the foam had a chance to fully expand.

upper rgt wdw fr blk foam b4 expanding

Upper right corner of a window with the Hannoband 3E tape.

Here’s a similar corner after the foam has had time to completely expand. The HF Sealant in the corner is just added insurance against air leaks.

upper left int wdw frame w: blk foam

Hannoband 3E tape fully expanded.

It was pretty impressive to see gaps like this on the day of installation:

hannoband-tape-before-full-expansion.jpg

Daylight coming in right after the installation.

Only to come back the next day to find the gap completely closed by the expanding foam tape:

lft side wdw frame gap filled w: blk foam

The gap is completely closed the next day.

I put the Hannoband on ice the morning of the installation since the cold is said to slow down the rate of expansion, giving installers plenty of time to set windows and doors.

A closer view of the Hannoband 3E tape fully expanded between the window buck on the left, and the window frame on the right:

lft side of frame close up blk foam

A closer view of the upper left corner of one of the windows after the Hannoband has had a chance to fully expand:

upper left corner of window w: Hanno tape and HF but before Profil

The tapes aren’t cheap, but I thought they were worth every penny.

For the bottom of the window, it wasn’t really clear if the Hannoband tape was appropriate for this area, so I followed Hammer and Hand’s lead, using backer rod to fill the bottom gap before applying HF Sealant (instead of Air Dam like in their video).

bottom of int wdw frame w: backer rod

Backer rod being installed into the bottom gap under the window from inside.

Lower left corner of the window after the Hannoband tape, backer rod, and HF sealant have been installed.

lower lft int wdw frame w: dab of HF

Interior lower left corner of a window after the Hannoband tape, but before the Profil tape has been applied. 

Later, for the basement windows, when I had the Prosoco R-Guard series of products on hand, I completely sealed the interior side of the two windows with the Air Dam product, which worked really well. I also used the Air Dam to seal the connection between my basement slab – rigid foam – and foundation walls. It worked really well in that application as well.

lower ft int base wdw installed

Basement window before the white Air Dam has been applied between the buck and the window frame.

Once the Hannoband tape had a chance to completely expand (roughly 48 hours), I proceeded to tape the perimeter of the windows and kitchen door, both from the interior and the exterior. This included the exterior sills (a common air sealing technique for European windows; considered a big no-no for American-style windows).

Unfortunately, when I was outside, before applying the Profil tape across the bottom of each window, I forgot to stuff in some Roxul Comfortboard 80 (as suggested in the Hammer and Hand video above). I only realized this misstep after reviewing photos for this blog post. Worried about potential negative consequences, I asked a question on the Q&A section of GBA, and I also contacted Floris at 475 HPBS. Although this roughly 1/8″ tall gap is an unnecessary thermal bridge (thanks to my mistake), it shouldn’t impact the long-term durability of the windows or the bucks.

I rented a FLIR thermal imaging camera to check this area, and to just see how the overall structure of the house has turned out in terms of air sealing and insulation (we moved in this past Spring, 2018). Unsurprisingly, the space between the window frames and the bucks/drywall is one of the weakest areas on the entire house. Fortunately, the sills don’t show up any colder than the rest of the frame (I’ll delve more into this in a later post, including some FLIR images from around the house, after detailing the installation of our exterior insulation and siding).

For the front door, we held off on installing it until later in the build in order to protect it from the construction process as much as possible.

close up lower lft wdw finished w: HF sealant

Interior view of the gap between buck and window frame taped with Pro Clima Profil tape.

Using the Profil tape for this made the process a lot easier. With its 3-part split backing, I could use the narrowest section on the window frame. It was important not to get too much tape on the frame in order to avoid interfering with final trim details (in our case, drywall returns).

On the exterior I tried using the Tescon Vana initially, thinking the gap was wide enough between frame and buck, but the Profil tape was simply much easier to use in tight spaces.

rgt side ext wdw frame finished w: tvana

Left to right: exterior gray window frame, Tescon Vana, and tape-covered window buck.

I added a little HF Sealant to all the corners just for added protection against air leaks and water intrusion.

taping ext of family rm window frame

Applying the Profil tape to an exterior frame.

From the outside in we had Profil tape, the Hannoband tape, and then another layer of Profil tape on the interior. Doing it this way involved some time and money, but I thought it was worth it to protect against air and water infiltration for the long-term. I would also only have one chance to get these details right, so some added redundancy also meant added peace of mind.

upper lft int buck corner finished w: hf sealant

Another view of a window completely taped and sealed in an upper left corner.

I also addressed the brackets on the top of the windows with a mix of HF sealant and tape after the Hannoband had fully expanded:

clip above window before Profil #2

First HF sealant applied around the bracket.

 

clip above window w: Profil

After the HF sealant, the Profil tape is applied.

 

 

Over-insulating High-Performance Window Frames

When the window bucks were made air and water tight, I took the advice of Hammer and Hand and over-insulated the exterior frames with rigid foam:

I wanted to use Roxul for this application, but it would’ve taken too much time to order and deliver to site (roughly 2 weeks), and the foam was frankly cheaper and readily available at Home Depot. We tried to go “foam-free” as much as possible, but this was an area where we made a compromise — insulated headers and the gap between our basement slab and foundation walls were the two other areas where rigid foam was used to any great extent.

The exterior aluminum cladding had been held back 1″ from the edge of the wood window frame, allowing me to install 1.5″ of foam between the edge of the aluminum cladding and the window buck (the 1/2″ gap around the perimeter of the window buck opening allowing for proper placement of each window).

over insulated frames

Over-insulating the window frame.

For the most part this went well, but there were some areas where the interior 1/2″ thick piece of foam did overlap the aluminum frame slightly. As Speier points out in the video, this probably short circuits the intended thermal break somewhat, but by how much I don’t really know (hopefully not entirely).

Also, even if over-insulating the window frames is executed perfectly, it still leaves the window bucks themselves as thermal bridges. I’m sure these show up in the PHPP (the Passive House Planning Package) used for energy modeling, but I’m guessing the energy penalty is slight.

Instead of using 3/4″ plywood or 2x framing lumber to create window bucks, some builders, trying to avoid this area of thermal bridging, have used Thermalbucks as an alternative, but depending on the thickness of the wall assembly there may be limits to their use.

Another view of the over-insulated frame:

lower lft wdw buck w: foam on frame

I’ll add additional photos of the windows and doors to a later blog post discussing exterior insulation, the ventilated rainscreen, flashing details, and our siding.

kitch dr from int w: sun

Kitchen door installed.

 

 

Issues Arise with our Unilux Sales Representative

The biggest disappointment regarding our new windows and doors was the behavior of our Unilux sales rep.

For instance, when Riggs and his crew were ready to set the first window in place we realized the integrated window sills were going to be way too short (the Unilux sills ship separately and need to be screwed to the front of each window unit). Our Unilux rep immediately suggested moving the windows farther out, near the outside edge of the bucks, in order to make these shorter sills work.

There are a couple of reasons why this was infuriating. First, and most importantly, it would’ve undermined the integrity of the windows since they would’ve been resting solely on the 3/4″ plywood window bucks, rather than the 2×6 framing (the units were heavy, especially our family room and master bedroom windows, which were each 9′ wide and 4′ tall). Secondly, his suggestion immediately told me he had not bothered to look at the construction drawings and Hammer and Hand videos I had emailed to him so he could order the proper sized sills and better understand the wall assembly the windows were going into. The drawings clearly note the proper placement for the windows, and I had explicitly noted this desired mid-wall position in an email.

Luckily, before I could say anything, Tony, one of the carpenters, spoke up and pointed out that the windows needed to be screwed into the 2×6 framing members. I can’t tell you how grateful I was that he had the courage to speak up (in my experience, most people wouldn’t).

The guys also pointed out that I could have custom sills made and then installed during the siding process. Not the end of the world. Sounds good.

suntuitive in crate

Suntuitive glass delivered in a crate. For our application it needed to be installed into two empty Unilux frames on site.

Later, our Unilux rep was leading Riggs and the guys through the process of installing the Suntuitive glass in the empty west-facing window frames. The guys seemed visibly nervous, and understandably so, as our Unilux rep led them through the process for the first time.

Once the Suntuitive glass was installed, the guys broke for lunch. The Unilux rep then pointed out to me when we were alone that of the 6 pieces of glass 4 of them had the Suntuitive glass logo installed upside down. He shrugged and smirked, perhaps suggesting that it was the carpenters’ fault, or that it was no big deal.

Fair enough, I guess, since it doesn’t impact performance, but boy does it look dumb.

Suntuitive upside down

Instead of taking a few extra seconds with each piece of glass to make sure that it had the proper orientation, our Unilux rep either forgot to do this, or he just didn’t care. It was hardly the carpenters’ fault since they had never installed Suntuitive glass before.

Still later in the day, when it came time to start installing handles, rather than having what I had ordered on site, our Unilux rep had a cardboard box filled with random handles of various styles: “Is this yours?” “No.” “Is this one yours?” “No.” He only had 2 of the correct handles out of 9. At the very least, this gave the impression that our Unilux rep was disorganized. It turned out he was missing all of the drip caps as well.

Near the end of the first day of installation the guys started installing the kitchen door. Once in place, our Unilux rep went to install the lockset. Something went wrong. He struggled for what seemed like an hour (it may have only been 20 minutes) to get it installed properly. Once he had it installed, he turned and began telling me I would need to remove it to file some parts down to improve the action. For a second time, Tony immediately spoke up, telling me explicitly not to do this, to just use it for a couple of months and it would be fine — which is exactly what happened.

With just my daughter’s bedroom window and the two basement windows left to install, the guys came back the following morning for a couple of hours to finish up. The Unilux rep showed up the second day, dropping some drip caps and the basement handles on a table for me to install. This annoyed me since I had never installed either, and it would’ve taken the Unilux rep a few minutes to do it himself while the guys were working.

And then later, as everyone was leaving, our Unilux rep suggested now that I had seen the guys install the kitchen door surely I’d be fine installing the front door on my own (these Passive House doors are heavy, and ideally require 2-3 guys to install them safely — and preferably by someone who has done it before). They’re also expensive, as I noted earlier, so why would I even contemplate installing it on my own. For a third time Tony probably saw a look of terror on my face, immediately spoke up, and offered to come back to install the front door once we were ready for it.

By chance, Tony somehow managed to be standing next to me each time our Unilux rep made an asinine suggestion. I can’t put into words how grateful I am that Tony spoke up for me and, really, the integrity of our build — he certainly didn’t have to, which probably tells you all you need to know about the quality of his character.

Happy to just have all my windows and kitchen door in, and knowing that Riggs and the  guys were willing to come back to install the front door, I said nothing to our Unilux rep about his behavior.

Later that week, however, we received the Unilux rep’s final invoice. It showed that he was double billing us for job site delivery. It was for just over $300. Not the end of the world, and an easy fix, but, nevertheless, annoying since it seemed to suggest he sent us a final invoice without consulting the original contract.

The invoice also had a storage fee for $1500. He had mentioned months before in an earlier email, after we had just fired our two GC’s, that storage fees were a possibility. At that time we had a lot going on, so I didn’t consult the contract we had signed with him. I just assumed storage fees were in the details of the contract, so when I got the final invoice I planned to pay for it.

But then my wife’s cousin found out about the storage fees, and he expressed surprise, telling us that, in his opinion, no one in the industry does this.

So I went back and looked at the contract. Not a word about potential storage fees. Nothing about when storage fees would begin to accrue, and no fee schedule noting how much per day, week, or month. In an industry plagued by delays, if storage fees were a legitimate billable cost shouldn’t our Unilux rep have the details outlined in his contract?

So then I separately asked a couple of people who work in the construction industry about our situation, one with over 30 years in residential work, the other with over 20 years in commercial construction. They, unsurprisingly, had similar responses:

“What’s in the contract?”

“Nothing.”

“Well, then…”

The one who works in commercial construction was more blunt:

“So it’s bullshit. He made it up.”

My wife wrote an email to our Unilux rep asking about the double billing for job site delivery and the storage fees, and expressing frustration with how he behaved on the job site during the installation. He responded with a series of emails that can best be described as unhinged or histrionic.

We contacted people above our Unilux rep to see if someone else could come back to finish things up — in addition to installing the front door, a piece of glass broke during installation (we think it was a manufacturing error in the glass), and a different subcontractor broke a part on a basement window that needed to be replaced. They told us our rep was the only one available in the Chicago area, probably, in part I’m guessing, because they wanted our Unilux rep to resolve the situation. Unfortunately, that didn’t happen.

He came back to the site to see the broken part on the basement window, removing the working stay arm (I assumed to make it easier for him to order the correct part, which was a cylinder on the frame that attached to the stay arm). He also dropped off the rest of the missing drip caps and the rest of our correct handles.

broken:missing cylinder on base wdw

Missing cylinder on the frame had been snapped off by a subcontractor.

A few months after this, in November, after drywall had started, the Unilux rep came back to install the replacement glass for the broken window, and the part for the basement window. He was visibly angry and petulant, clearly still annoyed that we had complained about him.

normal basement window

Here’s our other working basement window for comparison. 

When we were in the basement he just handed me the working stay arm that he had removed months earlier, apparently for me to install myself. When I pointed out that he hadn’t given me the part for the frame — the actual part that had been broken and needed replacing — he just stared at the open basement window for a few long seconds before we both realized he had failed to order the correct part.

It had been almost six months since I originally requested the part. Making matters worse, he told me from the outset that the window was unsafe to use until the part had been replaced, so we had never had use of this window since its installation.

He also asked if I had the Unilux owner’s manual. No, I didn’t. He never gave me one. I didn’t know one existed. Why he didn’t give me one the first day of installation back in June, or frankly prior to installation, via email, I’ll never know. Instead, I received the owner’s manual nearly 6 months after the windows had been installed.

The owner’s manual emphasizes how important it is that the windows be opened for at least 30 minutes 3 times a day for “forced ventilation” while drywallers are mudding to ensure no moisture damage occurs to the wood on the windows. If he hadn’t happened to be on site while the drywall guys were present, odds are I never would have received this information, thereby putting the long-term integrity of our windows at risk.

And if there had been damage, then what? Replace the sashes? Replace sashes and frames (the entire window units)? Who would’ve paid for it?

Bob Riggs, his son Brian, and Jason from JPK Builders, came back a few weeks after this to install the front door without our Unilux rep present (I didn’t want him near my house again, I think for obvious reasons). The lockset for the front door was installed without incident. In fact, it happened so quickly I didn’t even see them do it. Clearly there’s nothing inherently difficult about installing Unilux locksets.

We couldn’t be happier with Bob and all the guys he brought to the job site. They work hard, they’re detail-oriented, they’re willing to learn new ideas and techniques, and they have excellent communication skills — not to mention a high level of integrity. We wouldn’t hesitate to recommend Bob or JPK to family or friends. They were a pleasure to have on site, and they were very easy to work with. All of which begs the question: Why doesn’t Unilux recruit someone like Bob to sell and install their windows and doors? He’s used to selling his services anyway, and he has all the necessary construction knowledge to properly install high performance windows and doors. It seems like it would benefit both parties.

A few more months go by, it’s the end of June, 2018, and I still hear nothing about the missing part for my basement window, even though our Unilux rep had assured me in an email back in November, 2017 that he would make sure to order it and send it to me. We couldn’t use the basement window for almost a year at this point.

Reluctant to contact our Unilux rep again, I looked around on GBA and found Hawkeye Windows and Doors out of Iowa who installs Unilux windows. I spoke with Larry Martin, the owner, but it turns out he doesn’t sell Unilux windows anymore. Nevertheless, after I explain my predicament, he’s nice enough to offer to hunt down the same, or similar, Roto hardware part for me.

Within a week or two I have the part in my hand. Think about that for a second. I wasn’t even really his customer. It would’ve been so easy for him to just say no, he can’t help me. Instead, he invested time hunting down this random, miscellaneous part for me. I got better customer service from Larry for a $50 part than I did from our own Unilux rep after ordering a whole house worth of windows and doors. It’s astounding in a way, and what a world of difference from a client’s perspective.

During construction it feels like a miracle when you run across people like Bob Riggs, Tony, or Larry Martin — especially after having to deal with someone like our Unilux rep who needlessly made life difficult for us.

Unfortunately, when I go to install the part, although it could work, I realize it would require drilling new holes in the sash and frame. At that point, I get angry again: Why should I have to drill new holes in a brand new window simply because my Unilux rep is too lazy or incompetent to get me the right part?

I contact a couple of people above our Unilux rep, but I don’t hear back from them right away (one was out of town at the time), so I think I have no choice but to contact our Unilux rep again.

Here’s how our Unilux rep chose to respond to my email, carbon copying me and Eric Murray, the East Coast Regional Manager for Unilux:

“They broke this part after the installation; I had ordered one but then lost it [emphasis added].  According to what you mentioned to me a month ago.  I’ve thought Eric Whetzel was so upset with me after all ( despite all my goodwill , hard work and honesty trying to stay with them in good terms….it has been such an unfortunate experience with these clients; it never happened to me during my entire 30 year career…) I don’t understand why is he still speaking with me if he didn’t want to deal with me again? Anyway, if you did not order this yet, I will have Helmut ship directly to them and done with it”

It’s true, we wanted nothing to do with him, and I think for legitimate reasons. But what’s also true is that after more than a year he still hadn’t gotten me the part for my basement window — either out of malice, incompetence, or some mixture thereof. In addition, he claims to have ordered the part, lost it… and then what? He chose to do nothing? Unbelievable.

After this last email from our Unilux rep, he did, in fact, order the part for me, but when it arrived it turned out to be the wrong part, so it was totally incompatible with my window — wasting everyone’s time yet again.

Eventually, Eric Murray and George Wright from Unilux were nice enough to get me the part that I needed, although I’m sure they have better things to do with their time.

Just as a quick summary regarding our Unilux rep:

  • He ordered window sills with the wrong dimensions (wrong by almost 3″), even though I supplied him with construction drawings so he could get this measurement right. And his proposed solution to this problem ignored our construction drawings and what we were trying to accomplish with an “innie” window placement.
  • He didn’t bring most of the handles we had ordered to site. He never found the missing ones, so he had to re-order them.
  • He didn’t bring the drip caps.
  • He almost broke the lockset to our kitchen door, and then told me to remove it and file parts of it down to improve its action. Tony had to interject and explain why this was inappropriate.
  • He installed most of our Suntuitive glass upside down (4 out of 6 units).
  • He suggested I should install my $5,000 front door on my own.
  • He failed to give me the Unilux window and door owner’s manual, putting the integrity of our windows and doors at risk as drywall was being installed.
  • He tried to double bill us for job site delivery of the windows and doors.
  • He was going to charge us $1,500 for storage fees even though the contract says nothing about potential storage fees.

Obviously some of these items on their own would be no big deal, but when considered together what other conclusion is there but that this person is disorganized and can’t be bothered to get details right (this is the nicest way to interpret his behavior). This seems like an awful lot to get wrong for someone who was on the job site for only a day and a half.

The whole situation is unfortunate, as I explained to George Wright in an email, since we really like our windows and doors. Apart from an adjustment required on our front door and a kitchen window, they’ve been wonderful to live with. They’re beautiful to look at, and they function really well. All of this is undermined by the actions of our Unilux sales rep.

Of all the trades and services we knew we’d have to hire for our build, our Passive House window and door supplier was the last one we expected to have issues develop with customer service.

 

 

Suntuitive Glass Performance

Bob Riggs and the guys installed the windows with the Suntuitive glass at an ideal time of the year (June, 2017), just heading into the hottest and sunniest weeks of the year for us here in the Chicago area. It immediately gave us an opportunity to see what the glass can do, and how it behaves on a daily basis.

exterior view of Suntuitive in the evening

Suntuitive installed for our west facade.

It took a couple of days to get used to the colored tint, but we don’t even notice it anymore. It’s a subtle, beautiful gray that goes well with our charred cedar siding (more on that later).

We quickly realized how well the glass works in direct summer sunlight. The picture above doesn’t really tell you much, but in the picture below you can see just how deep the tinting gets when someone who’s standing in the middle of the window puts their arm out of an open side window. The Suntuitive glass really is like sunglasses for a structure.

suntuitive hand in open window

The Suntutive glass almost looks black from the outside when the sunlight is hitting it directly.

And even when it’s at its darkest, it doesn’t take long for it to go clear once the sun begins to set:

Suntuitive at sunset as tint fades

Evening, and the Suntuitive glass is going clear before nightfall.

And you get a real sense of just how effective the tinting is when you stand inside and look out between a picture window and an open window:

side by side suntuitive and sun

Side by side comparison: Suntuitive vs. direct sunlight.

Here are some more photos of the Suntuitive looking out from the interior:

Suntuitive at full tint in afternoon looking out Family Rm window

Even in the hottest sunlight, the interior side of the glass only warms slightly. It’s a really impressive product.

Suntuitive MBR-Family Rm at full tint in afternoon

Another view of the Suntuitive going clear in the evening:

Suntuitive at sunset looking into backyard

Suntuitive later in the evening, as it turns clear.

In the picture below, you can see the glass beginning to tint even though the sun hasn’t quite made it into the backyard to hit the Suntuitive directly from the west. Because the tinting isn’t automatic, its effect is subtle and feels natural as it changes.

me taping family rm wdw from int

Suntuitive glass starting to tint.

With most of the windows and doors installed, I could start thinking about installing my ERV and ductless mini-split system, planning for my first blower door test, and scheduling the install of our siding.

It felt like a really big step in the build — and it meant no more blue tarps covering the window openings to keep the rain out.

Although the days were long, it helped having my wife and daughter on the job site all the time. It also gave my daughter a once in a lifetime chance to play on an active construction site, and she had a blast.

John Ford - beast running away

 A John Ford “Searchers” shot of the Beast running off to play.

It’s been fun to mark progress in the build through photos. In fact, looking through photos sometimes produces real surprises:

beast-looking-at-view-from-br-for-1st-time-close-up

In late January, 2017, looking out the rough opening for her bedroom window…

 

looking out beast's br window for 1st time

Same opening in June, 2017. A really big moment in the build: getting their first look out of my daughter’s bedroom window.

Six months had gone by, and we had already survived a lot, with much more to come.

 

Attic Insulation

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For high-performance structures, relatively high R-values for insulation (at least when compared to current building code requirements) are required from the foundation all the way up to the attic (e.g., Passive House or The Pretty Good House).

After some initial research and product pricing, we knew we were going to predominantly use Roxul (with its recent name change, it’s now known as Rockwool) for our insulation needs. But after realizing blown-in rock wool wasn’t available (at least at the time anyway — presumably this will change in the future), and that batts didn’t make much sense for this application (too costly, and they’re considered more difficult to install properly), we knew we wanted some kind of blown-in insulation. The main options, currently, are fiberglass and cellulose.

Fiberglass vs. Cellulose
Best Attic Insulation

We wanted to avoid foam as much as possible throughout the build, both because of its  environmental impact and the fire risk associated with its use, so we didn’t consider spray foam as a real potential option.

After evaluating blown-in fiberglass and cellulose, we decided that cellulose made the most sense for us.

The next decision was to figure out how much, meaning how many inches did we want to blow into the attic. Our first builder was going to do R-49, which is the current code minimum standard here in Illinois. At the time, even before things went horribly wrong with this builder, this felt like too little. I had read stories about other Passive House projects using significantly more, but many of these were in even colder climates than ours (we’re Zone 5 here in the suburbs of Chicago).

How much do I need?
How much insulation is enough?

We decided that rather than settle on a hard R-value as our goal, we would just do a solid two feet of cellulose since we would be doing the installation of the material ourselves (less out near the 12″ raised heel trusses on the north and south sides of the house). There wasn’t a significantly greater cost in materials to go from an R-49 (just under 15″) to the approximately 24″ we blew into the attic.

After doing a little research, and speaking with a Passive House consultant and a local general contractor who consulted with us on various issues as they arose, the consensus seemed to be that attic insulation was an easy, relatively inexpensive place to sneak in more R-value, which is particularly beneficial in our predominantly cold weather climate (the ceiling/attic is where a significant amount of conditioned air wants to escape in the winter anyway). The blown-in cellulose, like the Rockwool, also has some nice sound deadening qualities as an additional benefit.

How much insulation do you need for Passive House?

The cellulose brand in our local Home Depot is GreenFiber, so that was the product we ended up using. Their product is DIY friendly, even allowing homeowners to rent machines for the actual installation:

 

We started out with 200 bags delivered to the job site. We assumed we were going to need more (the GreenFiber insulation calculator suggested we would need 250 bags to reach 2′ throughout the attic), but thought it might be easier to estimate a final total once the first 200 bags were installed.

The boys, who helped us with various grunt work chores throughout the project, were nice enough to return and help us bring the bags of insulation indoors the night before we started the installation in the attic. We set up a bucket brigade between the driveway and the kitchen, so it went pretty quickly.

guys w: cellulose

The boys after helping us bring in the first 200 bags of cellulose insulation: Luke, Smitty, Eduardo, my wife Anita, and Ricky.

On the day of installation, getting everything set up and started was fairly straightforward. Apart from a loose hose connection at the machine, which a small strip of Tescon Vana tape rectified, we had no issues with the blower. While my wife fed the bags of cellulose into the blower, I was up in the attic directing it into place.

The first couple of hours were actually kind of fun, but getting a consistent two feet of insulation throughout the attic was time consuming and eventually mind-numbingly boring. The first 12″-18″ weren’t so bad, it was having to wait in each section of the attic for that last foot or so to be blown in place that began to feel like real drudgery.

cellulose installed looking east

From the attic opening, looking east towards the front of the house.

It also didn’t help that I had a fever and a cold on the day of installation, so being up in the attic surrounded and covered in dust didn’t improve my mood. The process, although very DIY friendly, does require patience and a willingness to cover up — eyes, mouth, and nose — for adequate protection against all the dust floating around.

The day before blowing in the cellulose I went through the attic and marked my goal of 24″ of insulation on various roof trusses so I would have a good visual goal to shoot for. In fact, had I known just how dusty and challenging visibility was going to be during the blowing process, I would have marked every single roof truss at the 24″ level to make the job a little easier.

We didn’t have much in the way in terms of obstacles from various services, other than a few pipe vents for plumbing and radon, along with a small amount of electrical conduit for solar on the roof and a single light in the attic (we kept the majority of all services in our ceiling service core and our walls). This made for a fairly straightforward install of the cellulose.

cellulose installed looking west

From the attic opening, looking west towards the back of the house.

 

south east corner w: cellulose

Another view, this time a little further to the right, showing the far northwest corner of the attic.

 

vents by bench w: cellulose

Cellulose at its full depth around the plumbing vents and radon stack.

 

cellulose at the attic hatch

Finishing up. The attic access hatch is visible at the bottom of the photo.

 

bench behind attic hatch opening

The bench next to the attic access opening as we finish up blowing in the cellulose.

 

building up cellulose around attic chutes

Cellulose hitting the underside of the insulation chutes as it gets blown into place at the edge of the roof by the raised heel trusses.

Thankfully I was able to keep the cellulose out of the insulation chutes, instead slowly piling it up just below each chute. The siding guys already had most of the soffits installed (this was the end of October, 2017 last year), including a channel for air flow for our “vented roof” assembly, so any cellulose that found its way into the chutes and down into the soffits would’ve been a real pain to remove (I’ll have a separate post about the siding installation, including the many details of our rain screen and 4″ of Rockwool on the exterior side of the Zip sheathing).

The bench next to the attic access hatch ended up working out really well, and I was very thankful it was in place.

lid on bench w: cellulose

Lid of the attic access hatch sitting on its bench next to the attic opening after the installation of the cellulose is nearly complete.

By the end of the first day it was clear we didn’t have enough cellulose to finish the whole attic. We started with 200 bags, but we finished up the second day at just under 300 bags total (288 was the final number of bags installed, so a little more than the 250 recommended by the GreenFiber calculator). What we didn’t use we were able to return to Home Depot for a refund.

how much more cellulose

My wife wondering how many more bags until we’re done — unfortunately the answer was simply ‘more’ as she popped her head up into the attic several times towards the end of the installation.

Apart from the north and south sides of the attic around the raised heel trusses, we had a solid 24″ throughout the attic, in fact, a little more in the center of the attic where it was easiest to pile it up and let it accumulate (closer to 28-30″ in some areas). This probably explains, too, the additional 38 bags we used that exceeded the initial estimate by the GreenFiber calculator.

covered in cellulose

This is where a degree from Michigan gets you. #GoBlue. It was a long day.

On a side note, there was also some concern about the weight of the cellulose on the Intello (our ceiling air barrier), but in the end, even where the cellulose was at its deepest, there was thankfully very little sagging evident in the Intello. Even if it had been worse, the 1×4’s were in place to help support the Intello and the cellulose for the long term (the 1×4’s were spaced roughly 16″ apart between the 2×6’s of the service core).

sag1

Slight sag in the Intello evident after installing the cellulose in the attic.

 

sag2 closer view

Close up of the slight sag in the Intello near the west gable end of the house.

 

sag3 Intello touching 1x4's

Another view of the slight sag in the Intello as it touches the 1×4’s directly below it.

It’s worth keeping in mind that the cellulose will settle a bit, especially during the first few months. This is obviously very important when it comes to establishing what depth you’re initially going to blow in and your expectations about long-term R-value after settling has occurred (something to consider before signing a contract if you’re going to be hiring someone to do the work — both parties should agree and understand what the final R-value will be before the work commences).

I was back up in the attic recently as I finished up painting the master bedroom and closet. Since I already had drop cloths down, I thought I should take what will hopefully be one last look at the attic.

ladder in wic

Ladder under the attic access hatch in the master bedroom closet.

On average, the cellulose looks like it has settled about 2-4 inches below its original depth, depending on where I looked.

settling1

Some of the red horizontal lines at 24″ now clearly visible in some parts of the attic.

Even with this settling, the attic probably still comes in close to R-70 on average —significantly less out at the north and south ends of the roof with the raised heel trusses, but a little more in spots towards the middle of the attic where some red lines are still hidden below the cellulose.

settling2

You can see my red arrow and horizontal line at the 24″ level off to the right.

Just under or over R-70 in the attic is in tune with both the Pretty Good House and Passive House metrics for attic insulation for my climate region (Zone 5 here in the suburbs of Chicago).

While I was up in the attic I also noted that there was no evidence of any water or moisture damage on the OSB roof sheathing, or any indication of wind washing of the cellulose, so the attic seems to be performing as designed, which is a great relief.

 

 

 

Attic Access Hatch (Air Sealing #7 )

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Our attic is designed mainly to hold our blown-in insulation (a future post will go over the details), as opposed to a place for running HVAC equipment, conduit for electric, or as a potential area for carving out additional storage space.

Nevertheless, in order to have access to our attic for future maintenance or repairs, I installed a well-insulated attic hatch in our master bedroom closet ceiling.

Following Passive House and Pretty Good House principles required trying to protect the thermal envelope, even in this relatively small area, in order to avoid what can be a notorious point of air leakage and heat loss (i.e., the stack effect).

There were two main products I considered using for this:

Battic Door (R-50 / without ladder)

They also have a product that allows for a built-in ladder for easier access to the attic (you won’t need to drag your ladder in from the garage) while also maintaining a high R-value:

Battic Stair Cover

The other product I considered using was from ESS Energy Products:

Energy Guardian Push Up Hatch Cover

We ended up going with the Battic product, which I purchased through the Home Depot website (this saved me a trip to the store since it was delivered to site).

 

 

Some other products that I’m aware of include:

475 High Performance Building Supply used to sell a Passive House certified version with a fold-down ladder included, but I don’t currently see it listed on their website:

WIPPRO Klimatec 160

Or this product that also incorporates a ladder is available from Conservation Technology:

Attic Ladder

Because the Energy Guardian hatch is made out of rigid foam, I thought the Battic door was the better choice since it seemed like it would be a little sturdier and more durable. To be honest, once the product arrived and I unpacked it, I realized it was something I, or anyone with basic carpentry skills, could put together themselves (assuming you have the time).

Following the directions, I cut an X in the Intello on the ceiling between two roof trusses (and our 2×6 service core below each truss) in order to establish the opening for the Battic frame.

I folded the cut edges of Intello up into the attic for the two long sides of the Battic frame. For the two shorter sides of the Battic frame it was easier for air sealing to push the Intello down into the living area.

At this point I was able to screw the Battic frame into place.

looking up into battic attic hatch

Battic frame initially installed between roof trusses and 2×6 service core.

Once in place, I used a mix of Contega HF Sealant and Tescon Vana tape to air seal the Intello to the Battic frame.

battic - taped sealed to intello

Air sealing the Intello to the Battic frame (short side between trusses).

 

tescon vana air sealed battic w: HF behind Intello

Another view of the Intello sealed to the Battic frame.

 

looking down at air sealed battic from attic

View of the installed Battic frame from the attic.

 

attic access air sealed - attic side

Air sealing the connections between the Intello, the Battic frame, and the roof trusses in the attic.

 

air sealed corner of battic

Using HF Sealant to make the connections as air tight as possible.

Once the outside perimeter of the Battic frame had been air sealed to the Intello, the only place left for air infiltration was where the lid would meet the frame of the Battic hatch once it was installed (more on this later when I discuss my first blower door test).

There was some additional framing required, but it was just a couple of “headers” between the roof trusses to add structural integrity to the two shorter sides of the Battic frame.

attic access from below

Battic frame with additional 2×6’s on one of the short sides.

Since we were using a significant amount of blown-in insulation in the attic, it made it necessary to build up the sides of the Battic frame in the attic with some plywood to get the top of the opening above where the insulation would eventually stop.

 

 

 

 

Here’s another view of the 3 sides of plywood installed:

attic access looking down - directly

The fourth and final side of plywood was installed just prior to blowing in the insulation — in the interim this made getting in and out of the attic much easier.

After a couple of practice attempts, it quickly became apparent that raising and removing the lid once in place, and fighting to get it back down into the master bedroom closet, wasn’t worth the trouble. Instead, I built a small bench in the attic next to the Battic frame so I could push the lid up above the level of blown-in insulation, this way it could have somewhere to safely sit while dealing with any issue in the attic.

bench for attic access lid

Battic lid resting on the bench.

It’s very easy to grab the lid off the bench and bring it back down into position while slowly walking down the ladder in the master bedroom closet to make the final connection/seal.

Although the installation process was fairly straightforward and headache free for the Battic product, if I had it to do over, I think I would have the attic access point on the exterior of the structure, for example, on the gable end of the house in the backyard.

GBA – gable access to attic

Custom Gable Vents

AZdiy

Putting the access point above the air barrier would make meticulously air sealing the entry point for the attic less important, so keeping water out of the attic would be the main goal. An additional plywood buck would’ve been necessary, replicating what I did for our windows and doors (more on this later), but I think it still would’ve been the better option overall.

Putting the attic access on the exterior of the house would also mean avoiding an ugly hole somewhere in our drywalled ceiling. No matter how nicely trimmed out, these attic access points on the interior of a home never look right to me. We’ve tried to hide ours as much as possible by sticking it in our master bedroom closet, which has worked out well, but not having one at all on the interior of the house would make for a cleaner, better solution in my opinion.

If granted a do-over, I would also add a cat walk in the attic, through the roof trusses, in order to make getting to any point in the attic much easier to navigate, when necessary in the future, while also avoiding disturbing the blown-in insulation too much.

And here’s a photo of the bench in the attic, next to the opening for the Battic attic hatch, after the blown-in insulation was installed:

bench surrounded by cellulose

Bench for the Battic hatch lid.