April 4, 2022
Commercial Blower Door Test

Harsh winters are a common challenge for larger commercial, industrial, and multi-family buildings in Wisconsin, especially when they’re not sealed as tightly as they ought to be. These conditions can often cause comfort problems for those who live and work inside, as well as seriously high energy bills.

Accurate-Airtight Exteriors can help you resolve the symptoms of building inefficiency with data-driven solutions for your residential, multifamily, industrial, and commercial buildings!

Whether you want to improve your building's efficiency, comfort, or other inefficiency-related issues like moisture or poor indoor air quality (IAQ), bringing in a professional to perform a blower door test can give you all the answers you need to improve your building’s thermal and air barriers.

What Is a Commercial Blower Door Test?

A blower door test is a process of pressurizing and depressurizing a building to measure total air leakage rates to assess a building's thermal and air barriers. As part of the blower door testing process, Accurate-Airtight Exteriors also analyzes trouble spots with infrared imaging.

Since commercial buildings tend to be quite large, a series of large fans are often used to move enough air to achieve the correct amount of pressure. A series of data points are then collected throughout the duration of the test to show how tight and or leaky the building is, based on building envelope square footage.

Blower door testing is typically performed when the building is unoccupied so Accurate-Airtight Exteriors offers testing times very early or late in the day for occupant convenience.

What To Expect During Your Commercial Blower Door Test

Some building owners perform blower door tests to meet or pass certain efficiency standards, while others simply want to gain general improvement information. Whatever the reason is for your interest in commercial blower door testing, Accurate-Airtight Exteriors is here to walk you through what to expect during your test.

Building Preparation

First, all exterior windows and doors are closed. Then, the building’s HVAC grills must be either taped off or dampers mechanically closed. All interior doors must be propped open, and dropped ceiling tiles must be strategically moved to allow for air movement. 

Depending on the standard of testing the building requires, it can take a few hours to prepare the building. 

Fan Set Up

While the building is prepared, a series of fans in varying sizes are installed on exterior doors and bay doors. A rough measurement of the square footage of the building envelope is then calculated to determine how much fan strength will be required to depressurize the building. 

During fan setup, our technicians will also determine the impact of external factors such as wind, sunlight, and temperature, on the results of a blower door test and infrared imaging to ensure an accurate result.

Visual Analysis of the Building Envelope

While data points are taken with the blower door equipment, technicians begin to analyze the building envelope for air infiltration and exfiltration. 

Blower Door Test Results

After the blower door testing is complete, we generate a comprehensive report describing the conditions of the building and offering solutions to help you improve the thermal and air barrier of your building. Along with the report, A-AE can perform both contractual and consulting services to achieve the improvements that were reported.

Commonly inefficient areas include:

  • Penetrations around areas such as windows and doors
  • Roof/wall junctures
  • Roof penetrations
  • Wall penetrations
  • Structural beam penetrations
  • Thermal bridging of wood and metal beams

Commercial Blower Door Testing Requires Special Training

It’s not easy to make the switch from conducting blower door tests on single-family residential properties. Performing blower door tests correctly on larger commercial or multi-family buildings requires specialized training and equipment, including small electric fans, larger gas engine fans, and more to provide enough pressure to acquire accurate data and take quality infrared images.

No matter what your efficiency goals are for your large commercial or residential property, Accurate-Airtight Exteriors can help you make them a reality. 

Call the pros to improve the efficiency of your large building with commercial blower door testing. Call 866-582-4320 or contact Accurate-Airtight Exteriors online today!

Energy bills out of control?

Commercial blower door testing can help!


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  • I'm pleased to share a word of appreciation for the work A-A Exteriors did for our condo association. They conducted a blower-door test for our six-building, sixty units. This was a complex project. It required coordinating a large number of people and adapting to a variety of problems in each... Read More

    Alan Heggen, Hatchery Hill II Condonminiums, Fitchburg, WI