Blower Door Tests and Destructive Testing

Because this is an enclosure driven design, measuring the building’s baseline infiltration and conductance rates were crucial.  In laymen’s terms, we needed to figure out how leaky the building was and how best to seal those leaks.

To better understand sources of leaks and leakage paths, invasive/destructive testing and exploration were undertaken.  The team opened walls and window sills.  They cored into the roof.  They ran scopes through the ductwork.

Building Science Corporation also used a tool called a blower door test.  This special calibrated fan sucks air out of the building (or apartments) and simultaneously measures how fast air leaks back into the building.  During this process, leaks can actually be felt and overall air leakage in the apartment can be measured.

Using a blower door testing procedure called guarded blower door testing, the BSC team was able to isolate the leakage to the outside and measure that separately from leakage to other units or other parts of the building.  This procedure was conducted for a sample of apartments in order to produce an estimate of the outside air leakage for the overall mid-rise wall system.

Measurements of total leakage for individual apartments (leakage to outside plus leakage between apartments and other parts of the building) were used to develop air sealing measures to be performed inside the apartments.  The team developed air sealing performance targets (included in the project specifications) by using measurements of total apartment leakage before and after trial air sealing work was performed.

This is a blower door test. Implementing blower door testing in a multifamily midrise building is especially challenging. A team of building scientists installed the equipment at multiple locations at the same time to effectively measure air leakage.