A drafty home is an uncomfortable home. Undesirable cold air enters your home in the dead of the winter and cool air from a high-efficiency air conditioner can escape during the hot summer. Not only is this uncomfortable, but it can also lead to energy waste and cause higher energy bills. Conducting a blower door test as part of an energy audit can gauge how much air is entering and exiting your home. It is a crucial step in determining where your home will benefit from air sealing to improve its energy efficiency. Learn more about the blower door test and how it can serve your home.

What is a blower door test?

A blower door test is a powerful fan that is placed at the bottom of an exterior door. The remainder of the door is closed off with a temporary panel. The blower door fan effectively pulls a vacuum on your home to draw the outside air in through your leaks and drafty spots.

Oftentimes, a blower door test is paired with thermal infrared cameras to show where the outside air is being drawn into your home by the blower door. These cameras can also be used to determine where insulation is lacking in the home. Thermal infrared cameras are commonly used to evaluate doors, windows, floors at the basement rim joists, and ceilings where pot lights and exhaust fans are located.

What does a blower door test measure?

The blower door test measures the flow of air it's drawing through your leaky areas. That flow is reported in units of CFM50 or cubic feet per minute at 50 pascals (PA). Ecotelligent Homes uses that flow number to compare your home’s air leakage rate to what health and safety standards say your individual home should have. The blower door test can calculate Air Changes per Hour (ACH). The ACH should not exceed 3 level changes per hour when the home is depressurized to 50 PAs during the testing period in Michigan. The air change is calculated based on the volume of the home.

What are the two types of blower door tests?

There are calibrated and uncalibrated door tests. An uncalibrated blower door test can only determine where the home has leaks. A calibrated door test allows contractors to measure the amount of air leakages so the data can be compared before and after air sealing improvements have been made. Ecotelligent Homes provides calibrated blower door testing.

What equipment is needed for a blower door test?

Equipment needed for a blower door test includes the fan, a temporary panel to close off the door fully and a digital pressure gauge. The digital pressure gauge is called a manometer, and it measures the pressure difference between the inside and outside of your home. Additionally, some contractors will utilize smoke pens or thermal infrared cameras during a blower door test.

Is a blower door test worth it?

A blower door test will help determine if your house meets energy-efficiency standards. If your home does not pass a blower door test, you are likely wasting energy and your home will not have even temperatures throughout, possibly making it an uncomfortable environment.

When is a blower door test required?

Some states, such as Michigan, require a blower door test for all new residential builds as part of the building code. This was made mandatory by the International Energy Conservation Code (IECC) in 2015. The Building Performance Institute requires a blower door test on existing homes after improving the building envelope. Building envelope improvements could include upgrading insulation, caulking or foaming gaps, and replacing windows.

How do you prepare for a blower door test?

As a homeowner, you do not have to do much before a blower door test. A few things you can do to help a home performance contractor:

  • Close all exterior doors and windows and open all interior doors.
  • Move any large furniture that may be blocking access to the attic, crawlspace, furnace and water heater.
  • Clean out ashes from wood-burning fireplaces.

Ready for an energy audit?

Contact Ecotelligent Homes today to conduct an energy audit which includes a calibrated blower door test with thermal infrared images to determine where your home is drafty. Based on the findings of the audit, Ecotelligent can make recommendations for air sealing and insulation which often work together to improve the comfort of your home.