Blower-Door Airtightness

Turn a blower-door result into ACH50, CFM50 and NLR50 — and see which NBC level and programs it meets. Free, no sign-up.

A blower-door test depressurizes the house to 50 Pa and measures how much air the fan has to pull to hold it there. The same leakage can be quoted three ways: air changes per hour (ACH50), total flow (CFM50 or L/s), or flow per square metre of envelope (NLR50).

The NBC's airtightness levels (Table 9.36.6.4.-A) accept either ACH50 or NLR50 — whichever gives the better level. Tested levels earn Tier 2 energy points (Table 9.36.8.8.). Official results must come from a CAN/CGSB-149.10 test.

Taulien Construction · Fredericton, New Brunswick · info@taulien.com · 506-230-5131