Recap: 6th North American Passive House Conference

The 6th North American Passive House Conference was held in Silver Spring, MD (about 20 mins from downtown DC).  This was my first and I thought it was worthwhile just hearing some of the cool experiments people are doing all over the U.S. and Canada.  I am sure PHIUS will upload conference materials shortly on their site but here’re some of things I found interesting from the sessions I attended.

Sam Rashkin talked about how to move PH from early adopters to mainstream consumers.  Having grown the Energy Star for Homes program from nothing to nearly 30% market penetration in 15 years, I wanted to hear how he proposes to move PH to the mainstream.  In short, he offers a gradual process of improving building standards in the mainstream building market until they reach the “aspiration goal” of passive house.  I am not sure how I feel about that.  This seems to be the Microsoft method of putting out an acceptable product then putting out an incrementally improved version every few years.  I think there are enough people who know how to put out a product that is drastically better (i.e. a Passive House) that it doesn’t seem to make sense to do this gradually.  However, perhaps the problem is that the vast majority of consumers do not know about Passive House and do not demand to live in one.  Production builders will not make improvements on their homes unless they perceive a strong demand.

Jason Morosko explained how the ERV does/doesn’t dehumidify.  I am still a little confused… What I took away was that ERVs slow down the humidification of a home on a humid day but it cannot take humidity out of a house unless the humidity level is lower outside.  Also that minisplits will do enough dehumidification in most climates except in some very humid areas, where additional dehumidification strategies will be necessary.  I think the D.C. area is safe…  But I should probably research on this more.

Prudence Ferreria spoke about the reasoning behind Passive House’s 0.6 ACH standard.  Something that has always puzzled me every time I try to explain that standard to people.  I understand it as a qualitative measure of construction and that is the number that ensures safe moisture migration, but why 0.6 and not 0.65?  She said that tests are being done to determine the significance of 0.6 ACH and whether that number should be more climate specific.  The results of which will be presented during next year’s conference.  I am a believer of building a nearly air-tight house but I am glad someone is looking into the significance of this number.  Perhaps this is an opportunity that has opened up since the big split, that PHIUS can now freely question those assumptions.

My favorite lecture was one given by Thorsten Chlupp of Fairbanks, Alaska.  Over the years, he built many homes in an extremely cold climate.  He wanted to stop using foam due to the high embodied energy of foam production.  He presented the SunRise house which is his home and personal lab (Man, I would love to have one).  One of the  most intriguing parts about this home is the wall assembly, which was built with CDX plywood with 22 inches of cellulose outsulation (remote wall).  The cool thing is that the cellulose is wrapped in a vapor permeable membrane with no OSB or plywood holding it back on the outside.  This design ensures that the wall has no vapor barrier and moisture can escape from both sides.  The difficulty of implementation is off the hook!

The SunRise house uses no fossil-fuel heat sources.  Instead, it uses a combination of solar thermal, thermal mass (with a massive 8 million btu storage), and a stone masonry heater.  Thorsten said the last time he lit a fire was back in February.  I was floored!  To read more about this house check out these two articles:

Finally, Sunday was the local Passive House tour, which consisted of the Bethesda Passive House and our own Arlington Passive House.  I hope people enjoyed visiting my project.  I was seriously intimidated to talk about our project in front of an entire busload of experts!

A whole busload of Passive House consultants!

Home tour 1

Home tour 2

Home tour 3

Me and Jay Fisette


2 responses to this post.

  1. Great stuff. Not sure if you saw “Weird Hat Guy” but our own Jason Morosko was on hand and wrote a little review on the conference that was.


  2. Thanks! I talked to Wierd Hat Guy quite a bit at the conference. We are using your recouperator, should get installed next week. Stay tuned.

    and Yes, I read Jason’s review and retweeted it.


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