Passive House Design: Sealing Leaks for Air Tightness

| 1/7/2011 1:24:09 PM

Mark A. Miller is a practicing architect/builder/developer living in Chicago who designs projects around the country. His studio, Mark A. Miller Architects + Builders, designs and builds high-performing, energy-efficient homes that speak to the soul. Mark recently co-founded the Passive House Alliance Chicago and is lecturing about the Passive House standard throughout the Midwest. You can learn more about his unique approach to designing thoughtful homes at his websites: Zen + Architecture and Passive House Midwest. 

I wanted to start to go through some of the techniques that help one achieve the Passive House standard. We spoke last time about the difference between “passive solar design” and “Passive House design” as there seems to be much confusion. These are two different approaches to achieving better levels of energy efficiency. Today I would like to focus our dialogue on one of the key techniques in Passive House design—air tightness.

Have you heard the expression “It’s like having screen windows in a submarine”? In most American homes to date, the concept of air tightness has been marginal at best. The key concept here is to keep the unconditioned air (the outside air) from coming in to our conditioned air (you know, the expensive stuff our furnaces and air conditioners have produced for us) and killing its effectiveness. The more my expensive interior conditioned air stays “in”, the less my expensive air handling equipment will run to make more of it.  You lose it, you have to replace it.  So let’s keep it around as long as possible, is the Passive House mantra.

air leakage diagram 
Air can leak into and out of your home through various places. Illustration Courtesy Mark Miller.

So, let’s look at our standard American home’s building components and get enlightened to all of these “built-in” opportunities for outside air to come in to our conditioned spaces. Here’s a list:

Wall caps at dryer vents: these are usually made of thin sheet metal, sometimes with a damper, which you hear flapping in a winter breeze, just to remind you of all the cold creeping into your house

7/8/2014 5:06:50 AM

Every home has a accouterments aperture assemblage assimilation in its roof. These are usually beyond pipes of four to six inches in diameter. It’s important that all aqueduct penetrations are appropriately closed for air tightness, not alone at the roof, but area it passes through any material. Passive House practices accepting no aperture brim in the alfresco walls.