We thought it would be a great idea to see just how "leaky" the home is before we began the process of remodeling the home. A Blower Door Test pressurizes, and depressurizes, a home to see how much air infiltration there is ("leakiness" of a home to air.) In our temperate, coastal San Diego climate zone we find that adding a higher level of thermal efficiency to a home is not going to make nearly as much difference to the thermal comfort and energy efficiency as making the home more airtight. By improving thermal efficiency, think more insulation, thicker walls, and higher performance doors and windows. Think expensive, also.
Well, the existing structure is so leaky that we couldn't even pressurize the home to the required standard of 50 Pascals in order to do the test (a Pascal is a unit of pressure.) We could only get it up to 43 Pascals at the highest airflow rate that the Blower Door could provide, 3,175 cfm. That means that we were blowing 3,175 cubic feet of air into the home and that same air was leaking out of the "envelope" (floors, walls, and ceiling/roof.) Not up the chimney, not through the bathroom ventilation, etc., we sealed those areas off. This home was like swiss cheese.
All that air infiltration would have made for a far less comfortable home than we will be rebuilding it into. And to make up for that lack of comfort in the heating season, a lot of heating was probably required. And all that heat would have kept going out the holes of the swiss cheese structure. Wasted energy, wasted money.
We will be performing additional Blower Door Testing during certain phases of construction to see how much we improve the efficiency of the envelope. Stay tuned!
|Positive pressurization attempt results|