Hi everyone, hope you got a chance to read part 1 of the virtual NESEA Passive House tour. (Remember, if you’re going to NESEA and you want to join the actual tour of Passive House products that I’ll be leading on the BE12 trade show floor, be sure to sign up for my workshop.)
We left off with the excellent options from Zehnder and Ultimate Air. To finish that discussion, The UltimateAir RecoupAerator is the only American-made high-performance ventilator on the market that meets Passive House efficiency requirements. It is very affordable, but does have some more maintenance needs. This unit also has the best humidity recovery in ERVs, which is especially interesting for the humid North American climates (of course, it works just as well in the dry climates). One unique feature: the designer has a limited ability to dial in the humidity recovery level according to climate. Very cool!
Now, on with the tour. We touched on airtightness when talking about the excellent 475 product suite.
What about the rest of the envelope? Aren’t we talking super insulation? What about walls? NESEA has a range of Passive House walls on the floor. Here are the highlights: GreenFiber, National Fiber and International Cellulose Corp. are classics when it comes to super-insulated wall systems. Not only was cellulose used in the very first projects in Canada when Passive House principles were invented in the 70s (yes, we do have long-term experience with these wall systems, this is nothing new!) it also rates high in the context of the embodied energy discussion. Given the amount of material required, it’s a valid discussion.
I lean to using materials with very low embodied energy as sound good practice for Passive Houses. Cellulose has one of the lowest embodied energies and is only beaten by — you guessed it — straw bale. Cellulose is also a safer choice when it comes to the hygrothermal wall performance of a super insulated wall. Super insulation means very little heat loss from inside into the wall, therefore less drying potential for the wall and colder exterior sheathing surfaces, which is potentially a higher risk for condensation. Cellulose can mitigate some moisture that might occur, is more forgiving than other materials and if the wall was designed in a diffusion-open fashion (as it should be for a Passive Home) then potential moisture in the wall will dry out during the in-between seasons.
Another popular insulation choice is foam insulation systems. Icynene Spray Foam and Vantem Panels offer two environmentally sound solutions for those who like to use foam products. Foam is liked in this country for very good reasons: in North America we have many humid climates. If we super insulate, we increase potential for condensation in the wall. Add bad construction and failed air tightness measures and the building will have serious problems. To address these risks, many have come to rely on foam’s benefits of added air tightness, moisture retardation and relatively high R-value.
The 2 lb closed cell spray foam from Icynene has none of the high Global Warming Potential (GWP) blowing agent controversy attached to it. It is water blown, and eliminating the concern. Vantem Panels are another excellent alternative. They use Expanded Polystyrene for their Structural Insulated Panels. The blowing agent of this foam product is pentane, which has a GWP of only 7 (compared to approx. 1000 for the most commonly used high GWP blowing agents). In addition, Structural Insulated Panels (SIP) make it really easy to meet Passive House air tightness expectations. The monolithic panels themselves are airtight, if penetrations are avoided or detailed in a very conscientious manner, then the only connections left to air seal are the panel junctures and corners. An even better foam alternative is graphite-enhanced high density EPS used by some SIP manufacturers. This type of foam yield R-values in the range of 5 per inch.
Now, if you’re building a Passive House, you have all the materials in the shopping cart. Now, what else is missing?
You might want to find an architect who ideally also is a Certified Passive House Consultant, CPHC. To find a professional you have three options: Visit the Passive House North East (PHNE) table at NESEA BE12. It represents the forum of professionals in the Northeast. Also, if you are interested in getting hooked into local Passive House events, meetings and local conferences, get involved in the PHNE local meet up groups. It’s a great place to start for local expertise and advocacy work. These folks can tell you everything about available incentives for your Passive Dream Home, which will make it look even more attractive. (Massachusetts and the Northeast are ahead of all other regions in that regard — NESEA might be able to take credit for some of that too!).
If you want to go mod (modular) you’ll find the modular homebuilder who built the very first modular Passive House in the US! Check it out, stop at the Preferred Building Systems booth. The modular project is the Charlotte Habitat for Humanity Home in Vermont. Preferred Building Systems was the first one to put a fully certified Passive House together in the factory. That deserves great recognition for the vision and ability to make it happen!
If you want to build your Dream Home in some other part of the country, go to the PHIUS site to find a Certified Passive House Consultant (CPHC℠). You can sort by location to find CPHCs close to you. PHIUS is the leading technical research organization in terms of all things Passive in the United States and has trained more than 600 consultants over the past five years and certified more than 300 are nationwide. PHIUS also offers PHIUS+ project certification, a conscientious Passive House quality assurance protocol that assures that you get what you pay for. You can also take a look at the certified projects (more than 100 are in the review process).
Also visit the Passive House Alliance-US site. PHA-US is a PHIUS partner, a national membership organization providing education, networking and advocacy for the community. It has 11 chapters and affiliates active across the nation with more applications pending. Its members are architects, builders, manufacturers, other associates, advocates and Passive House enthusiasts. PHA-US has kicked the gear into overdrive in 2012. Member benefits are growing fast. National webinars on Passive House topics are being shared between the regional groups, and conferences are planned. To become involved in this exciting national effort to help make Passive House mainstream with US builders, homeowners and government policy makers, join the PH Alliance today.
Finally, some special recognition: Having been a long-time forward thinker and leader in education about the built environment, Yestermorrow Design/Build School is the first educational institution to license the PHIUS Certified Passive House Consultant training to integrate it into its training offerings. Kudos to this pioneer in so many realms of construction and environment.
This past January, Yestermorrow hosted the first inaugural Passive House Consultant class. It was a great success with great feedback; more classes are being planned for next year. Twenty-four students, instructed by myself and Marc Rosenbaum, huddled in for 9 days straight in what was easily the most intense studying setting ever. Fifteen of them took the final exam on day 9 and 13 passed! Watch out for the graduates from this class, they excelled in that learning environment like no others! And, Yestermorrow’s library is unprecedented in regards to items about Passive House history in the United States and Canada from the 70s until now. This organization is a leader in Passive House education.
Thanks to NESEA and all the friends out East that have given me the opportunity to do this review and I hope to see a few of you on the NESEA BE12 trade show floor! Be sure to sign up for my workshop — you need to sign up for the workshop to take the tour.