Air Leakage – Impact on Buildings

Have you ever made the mistake of wearing a loose-knit sweater on a windy day? If you have, you have a powerful reminder of how insulation (the sweater) can be overwhelmed by air leakage (wind).

The same principle applies to buildings but its rarely as obvious as the painful biting cold of a winter wind whipping through your sweater. The average home has lost thousands of dollars in wasted energy bills and the occupants often deal with uncomfortable rooms.

What do homeowners typically do with these comfort problems? They add insulation, increase the HVAC system, replace windows, or add space heaters.

While there’s nothing wrong with adding insulation, there are often air sealing opportunities that go unfixed that could have a far greater impact. Going back to our sweater example, we know that putting a wind-breaker jacket (air sealing) over the loose-knit sweater will have a much larger impact than adding another loose-knit sweater.

I’m not advocating that we bring back the windbreaker suits of the 1990’s. But I do think we could stand to focus on air leakage a little more.

When it comes to buildings, the places that air leaks occur are often hidden. Common areas include holes surrounding plumbing and wiring, gaps around HVAC ducts, and gaps around ceiling fixtures like fans and recessed can lights.

Measuring and finding these holes can be difficult. Fortunately for us, we can use our understanding of pressure diagnostics to find and seal these holes.