John Semmelhack of Think Little ran his final blower door and duct blast tests at Riverbluff today as part of our Earthcraft certification. When he was setting up the blower door fan to stabilize the house pressure for leakage testing, he found the house so tight that he had to add a “C-Ring” to the fan to get enough resistance. The result: 0.06 ACH = 357 CFM50/5898 SFBE (Air Changes per Hour = Cubic Feet per Minute of air leakage / Square Feet of Building Envelope at 50 Pascals of air pressure). Let’s just say that the house is very tight. Tighter than the almost 100 Earthcraft houses that John has tested to date. Good thing we have an Energy Recovery Ventilator to bring in fresh air to the home.
The duct blast test then showed 0 leakage, which was to be expected, as we have all the HVAC duct work in the enclosed conditioned space of the house. We were also a little proud that John had no comments to make about the HVAC equipment, as we had already made a few key adjustments back before the drywall was installed. Now we will wait for John to finish his modeling and submit his paperwork to Earthcraft to get our HERS (Home Energy Rating Score) and Earthcraft rating.