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sla calculator

What is SLA?

SLA stands for specific leakage area and describes how much air enters or escapes from a building (building infiltration). The lower the number, the tighter (less leaky) a building is. Air Leakage is important as the air escaping from the building represents energy loss. The specific leakage area is calculated using inputs from a blower door test.

The average residential building leakage in California is estimated to be SLA 4.9. Buildings with high SLAs are drafty, uncomfortable, and hard to heat and cool. Conversely, a building with an SLA that is too low can experience moisture and mold problems and have poor indoor air quality if not ventilated properly.