2/21/14 Preliminary Blower Door Test Exceeds Expectations
Friday, we conducted a preliminary blower door test at the house to learn where we are standing with tightness of the building envelope.
Using a powerful fan and a pressure sensitive instrument called a manometer, we are able to determine at what rate air from the outside is exchanged with inside air through leaks in the house. The fan can be used to pressurize or depressurize the house and then measurements are taken. For this test, we attempted both ways to cross-check the measurements.
In order to meet Passive House certification standards, buildings must score a .6 ACH (Air Changes per Hour) on the test, meaning that 60% of the total volume of air in the house is exchanged per hour.at 50 Pascal. 50 Pascal is the industry standard for this kind of measurement. Most homes in the area score around 7 ACH (code), whereas more efficient Energy Star homes will range from 2.5 to 4 ACH. Our goal for this preliminary test was to score a .25, which would indicate excellent tightness of the envelope and be well within the measurements for Passive House.
Using a burning stick of incense, Kunal Alaigh from the Levy Partnership, checks by windows and other possible thermal bridges for leaks in the envelope (while making the house smell delightful). He finds a few areas that could be better insulated, good information as the building continues, in anticipation of the final test.
Our preliminary blower door test calculates out as .178 ACH, exceeding our expectations for the day’s goals! .