The Simple Task of Mitigating Air Infiltration Should Be the First Step in Improving Existing Commercial Buildings’ Performance
WRITTEN BY | FRANK R. PIPAL 48 RETROFIT // March-April 2013
BUILDING ENVELOPES
I
ssues associated with air leaking through a building’s thermal shell have been steadily gaining attention in the construction industry. It’s
for good reason: A leaky building will cost appreciably more to oper- ate in energy costs and reduced equipment life; it will be less du- rable; it will be uncomfortable and potentially unhealthy; it also will contribute more air pollution than a tightly constructed building. Not long ago, it generally was
believed that a tightly constructed building would lead to problems
with mold growth—the mere mention of which could ruin an entire decade of a contractor’s life. We now know mold growth in a tightly constructed building is likely only to occur if proper mechanical ventilation is not installed. These days, the saying is: “Build it tight, and ventilate right!”. However, properly ventilated or
not, air leakage through the build- ing shell will cause condensation in wall cavities and increase the probability of mold growth in most U.S. climate conditions. Whenever