True or False: Clark Hall leaks like a sieve?Answer, somewhat. Cozy Home performed building envelope air barrier testing on Clark Hall at Smith College on July 26th. The single point test required three blower doors and the building leakage rate was 14,000 CFM50 for the 7,000+ sqft administration building. What does this number mean? When calculated for the amount of air leakage per hour (ACH) the volume of air in the building changes over one full time per hour (ACHn=1) under certain environmental conditions. This non-stop leakage is responsible for significant energy waste during both winter heating and summer cooling, along with chronic comfort challenges. This may seem high; however. This air-leakage rate is not horrific on a relative scale when compared to other 1880’s circa buildings that we have tested. We have seen as high of 3 air changes per hour!Smith has set an aggressive air leakage reduction target of <5,000 CFM50 or what other building scientists name at 0.25@CFM50/ssf ( 1/4 air changes /hour at 50 Pascals pressure, per shell square feet). If achieved this would represent a reduction over 70%. This would be remarkable! Projected energy savings per the calculations provided by the Architect are above 60%! |
 Double Blower Door at Clark Hall |
 Two Seasons of an Exterior Wall... infrared speaking. Summer and Winter |
 uninsulated wall....summer hot (yellow bays with cooler framing). Heat energy in! |
 uninsulated wall.. winter cold (blue bays with warmer framing)... costly heat energy out! |
