BLOWER DOOR TESTING
Air flow through a building can have a powerful impact on our level of comfort in our home, the quality of air we breath and the resulting energy bills. In fact, study after study demonstrates that air leakage can increase heating and cooling costs by over 30% while contributing to health and safety problems. Blower door testing provides a way to quantify air flow and the resulting cool/heat loss along with a way to pinpoint where specific leaks are.
A Blower Door may be used to test the performance of an existing home that is expected to undergo energy efficiency improvements and new construction to ensure a tight energy efficient envelope. Testing a home’s or building’s air-tightness (or leakiness) is one of the most effective ways of determining the energy performance and trouble-shooting areas of concern.
If you’re building a new home, the best time to conduct a blower-door test is after the home is insulated but before the drywall is hung. If the test reveals major problems, the leaks will be easier to fix at that point than later on.
Energy Code requires that the Natural Air Changes per Hour for new construction must be at .35 or lower. Using a calibrated blower door will be able to quantify the results of your home before it is too late – and costly – to repair the problems.
Also, it has been our experience that contractors (especially insulation contractors) tend to be more detailed in their installation practices if they know the quality of their work will be tested at a time when improvements may easily be demanded based on its performance, or lack of.
Please view our Just Because section to view common assumptions and mistakes made when building an energy efficient home.
Why test the tightness of a new home:
It may be used as documentation of airtightness levels needed to qualify for certain home labeling programs, including Energy Star or the Louisiana HERO Program.
It is the most effective testing method used to determine if the house is sealed properly before it is too late or too costly to correct commonly made mistakes.
Proper sizing of the HVAC unit is based on assumptions about the NACH (natural air changes per hour) of the structure. Energy Code dictates that a Manual J Eight Edition be performed to determine the proper tonnage of the air-conditioning required to be installed. The air-leakage results of the blower door test will give the truly concerned HVAC contractor valuable information concerning the tightness of the home and therefore the btu’s of heating and cooling required from the installed system.
The tightness or leakiness of the home along with proper type and installation of the HVAC system will have a large impact on the moisture levels and energy bills of the home.
Existing Homes - Renovation & Retrofit Work
There are at least two reasons to conduct a blower-door test on an existing house: to determine how leaky it is, and to help locate and fix the leaks. When a blower door is used to help a homeowner or contractor locate and fix leaks in an existing house, the procedure is called “blower-door-directed air sealing.” The leakier a home, the more economic sense it makes to invest in sealing it or hiring an air-sealing contractor.
Many existing homes that have been built very recently within the last few years may also have major concerns associated with them. Quite often homeowners of fairly new homes experience problems with being unable to cool or heat their homes appropriately, may experience “hot” or “cold” spots, along with high energy bills. The first step in diagnosing these concerns is to run a blower door test.
For a more detailed and thorough energy audit a homeowner may also incorporate duct blaster testing along with an infrared inspection.