Discussion on:

Q&A: Sam Hagerman, president, Passive House Alliance U.S.

Doesn't the house start to stink? Do the inhabitants suffer from oxygen deprivation?

Many passivhaus buildings have central ventilation systems, similar to ducted heating. The rate of air flow will probably be a lot slower, but it seems to be enough. The bigger problem is when a proper passivhaus has windows which don't open, but you require ventilation (e.g. using domestos to clean a room) or to clear smoke from the kitchen if somebody leaves the bacon on the stove for too long...

When I read this: "(38.1 kilowatts per square foot per year)"

I wondered, was this meant to be kWH per square foot per year? Or did you actually intend 38.1 thousand joules per second per square foot per year?

Where I live (the Gulf coast), a larger concern than heating a home is cooling it during the hottest months of the year when the heat & humidity are unrelenting. How does a Passive House address those problems?

Much has been written over the years about sick houses and buildings. Buildings that don't breathe (enough) can develop very toxic air . This is especially true with new buildings, when all of the glues and paints 'gassing-off' (curing). A good air heat exchanger would be severely tasked. There are products that don't gas-off, or that supposedly are safe, but most of them are poor performers, or are expensive. It would be interesting and informative for someone to explore the actual costs to build one of these passive houses in Oregon in US Dollars.

Really? They didn't cook anything on a stove or oven? They used no artificial lighting? (even LEDs have a wattage rating lost as heat). They had no electronics or computers that were used in the house? No hot water for laundry or bathing? I find this claim to be highly suspect.

But they spent 12,000 $ for 24/7 incandescent lighting.

The whole argument hinges on whether 0.6
air changes per hour is suitable for an
occupied dwelling.

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Great article - well done to Sam.

A lot of comments above concerned with issues around indoor air quality. As someone who has lived in a Certified Passive House for over 8 years, let me reassure you that the air quality is really superb. It is well known that air quality in an airtight house with a ventilation system is way better than a normal leaky house. A typical example would be carbon dioxide concentration in bedrooms which in a normal house will climb towards 2,000 PPM at night, but only reach 800 PPM in a Passive House. By the way, international norms suggest that indoor air quality is lessened where carbon dioxide exceeds 1,200 PPM. Hence the subject line of this comment, built tight, but ventilate right!

One other comment, the Passive House Academy is accredited by the Global Passivhaus Institut as a Passive House Building Certifier and is working on several projects all over the US.

Be smart - build Passive.

Tomas O'Leary, MD, Passive House Academy

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