ASHRAE Journal - May 2011 - 64

building sciences
become a “boutique program” that would garner all kinds of press but not do much in terms of number of houses actually constructed. I was proven right. Sorry, fellow Canadians. It was the wrong number at the wrong time. It still is. Anyway, nothing much happened over the next decade, and R-2000 fizzled out. I came to the U.S. to seek my fortune and got involved with a few big builders. Folks who built 20,000 to 30,000 houses a year each. It turns out that a bunch of the big U.S. builders had comfort complaints because they were building houses with big holes. I figured I knew about holes and I was off to the races. The good news was there was no standard so I could make one up. I had already had experience about how to make things up. I picked one of the big builders’ worst divisions in terms of comfort complaints—it turned out to be Chicago—and focused on making the comfort complaints go away. Notice, energy had nothing to do with any of this. I figured that if they got rid of the big holes the comfort problems would go away. The list of big holes was pretty easy to compile. Bathtubs on exterior walls, fireplaces and chimneys on exterior walls, garages attached to houses with bedrooms over them, cantilevered second floors, interior soffits dead ending into exterior walls and dropped ceilings under attic insulation. Done. Make these go away with draftstopping and, presto, the comfort problems would go away. In one year we did a thousand houses and, sure enough, the comfort problems went away. I measured a lot of stuff with blower doors, and the houses were coming in at around 3 ach@50 Pa—consistently. Apparently, the Swedes had been on to something. I wasn’t completely dumb by then and made sure that every house had a controlled ventilation system and made sure that all the gas furnaces and gas water heaters had combustion air and it became pretty easy to predict them, especially when you could get your hands on a thousand of them in houses built in a similar way that you more or less had control over. You know where this led—a utility bill guarantee program and marketing heaven. And in a real sweet twist, a comfort guarantee was added as well. Bottom line, if you get below 3 ach@50 Pa the comfort problems go away, things become predictable, and you save energy. Add the controlled ventilation piece and the combustion safety piece and nobody dies and nobody gets sick and life is good.7 It got even better. The Building America Program came along and focused on production housing, not boutique housing. Guess what the airtightness number for Building America more or less became? Yup, 3 ach@50. Then Sam Rashkin8 came along with EPA’s ENERGY STAR and got his hands on the “big holes list,” which became the “thermal bypass list” and things began to really happen. You could actually do this on large numbers of houses. You could actually do a “code change thing” and get folks on board if you had a track record and lots of houses under your belt. Well, it is happening—and without a major food fight. The codes are going to go to 3 ach@50 Pa and 5 ach@50 Pa, depending on where you are. This is good. But, the true believers are never happy because 3 ach@50 Pa is too high for them; 1.5 ach@50 Pa is the number for them. After all, the argument goes, the Canadians did it. Well, actually no. We did it on a ridiculously low number of houses because it is really hard to do, and quite frankly, not worth it, especially if you then overventilate the houses—not even an HRV can save you. New Canadian houses are now pretty tight—less than 3 ach@50 Pa—getting close to 2 ach @50 Pa, but not 1.5 ach@50 Pa; and the houses are overventilated, so we don’t actually save that much energy.9

Photo 8: Draftstopped Fireplace. Pretty easy to get right if you know this is a really big hole. The draftstop makes the fireplace work even better because the fireplace is also warmer. Warm fireplaces draft better. Warm chimneys draft even better.

Photo 9: Draftstopped Soffit. ’Nuff said. and that we had tight return systems so we didn’t back draft anything. It became even easier when we started specifying sealed combustion 90 plus gas furnaces and power vented water heaters. Then it got even better. The utility bills dropped big time. I started tracking them,

7. Houses without controlled ventilation systems are subject to increased levels of contaminants as airtightness goes up. Houses with standard atmospherically coupled combustion appliances without provision for dedicated combustion air are subject to back drafting and spillage as airtightness goes up. Controlled ventilation and combustion safety are not only good, but necessary. 8. You all have no idea of the grief Sam took initially with all of this. Lucky for us, he stuck with it. Good job, Sam. Here is the link to the checklist and have at it: http://tinyurl.com/thermalbypasslist. 9. But hey, we have lots of energy up in Canada. So much so, we want to sell it to you if you would only let us build that pipeline to you from the oil sands, so we can afford to overventilate. If you won’t let us build the pipeline to you, we will just sell the stuff to the Chinese. They at least can afford to buy it. Either way we get the money to subsidize our heath-care plan. You know the one. The one that is very expensive with the long lines. Ah, I hear you are getting one of those, too. Actually, the U.S. spends more per capita on health care than Canada does and has a lower life expectancy. Maybe those lines aren’t so bad, eh?

ASHRAE Journal

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May 2011

ASHRAE Journal - May 2011

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