• Test-in, test-out, test-often

    Air leakage through the building envelope is a major source of heat loss and moisture infiltration into the home. A major objective of any retrofit program is to reduce uncontrolled air infiltration to a minimum.

    Blower door testing has provided the ability to accurately test and quantify the effectiveness of a building’s air barrier system. The blower door equipment depressurizes the house to a fixed amount (50 Pascals.) An instrument (manometer) is used to measure the amount of air passing through the building envelope – this can pinpoint the number of air changes per hour (ACH) in your house. “Natural” ACH is the number of times per hour the complete air volume in your house is exchanged for outside air under normal (not test) conditions. For example, a house with .2-to-.4 natural ACH is considered tight, most houses have .5-to-1.25 natural ACH, where the upper end of this range is considered very leaky.

    In the hands of a well trained building analyst, the Blower Door test and it’s complement the Duct Blaster can accurately identify the major sources of air infiltration and HVAC duct leakages in your house. Once identified, it can provide a roadmap for sealing your home – typically reducing natural ACH from the average of .8 ACHn to .5 ACHn. Testing the effectiveness of the building’s air barrier system at the end of a retrofit permits the owner to have a concrete evaluation of the efficacy of the retrofit work. It also allows the contractor to establish concrete program goals.

    Green Energy Systems uses the blower door and duct blaster through out our work to direct and confirm the effectiveness of our work effort.