Call Brian Bryant 941-321-7745

Blower Door Testing

Why Test the Building Envelope?

Air leakage is responsible for as much as 30% of all the energy lost in a building. The average building has enough air leakage to add up to a two-foot-square hole, the equivalent of leaving a medium sized window wide open 24 hours a day.

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Advantages of Blower Door Testing

Finding and addressing leakage is often the least expensive way to save that energy. A Blower Door test can also identify potential safety, air quality and moisture problems before they happen.

To be Florida Code compliant, A blower door test must be conducted and passed on new residences before the Certificate of Occupancy (CO) will be issued. The International Energy Conservation Code allows either a Blower door test to prove adequate air tightness, or a visual inspection by the code official of a list of seventeen or more air barrier and insulation components. A Blower Door test takes about 30 minutes to setup and run, plus some time to measure the conditioned volume of the house, but the inspection can take much longer. Generally building officials prefer the blower door test because either it passes or fails.

Pre-Test Requirements

  • House is complete and move-in ready, power must be on
  • If attic is not sealed with open or closed cell foam, seal all penetrations entering attic: electric wires, can light or ceiling fixtures, plumbing lines, HVAC registers
  • Weather stripping installed on all windows & doors
  • Seal all penetrations made to the exterior walls: cable or ethernet lines, HVAC lines, Gas lines, plumbing lines, electrical lines/ conduit, etc.
  • If possible, install gasket at Attic hatch cover
  • Fireplace damper installed and operational
  • Clothes drier vent backdraft damper operational
  • All windows and doors closed and latched, none broken
  • HVAC air handler fully installed

How does a Blower Door work?

A calibrated fan is mounted in an exterior doorway and blows air into or out of a home. The fan creates a test pressure of 50 Pa (similar to a 20-mph wind) which is displayed on Channel A of the gauge. Channel B displays the pressure signal from the fan which may be displayed as CFM or air changes per hour, depending on the selection made on the Mode key.

blower door set-up graphic

How tight does the envelope have to be?

The building must have 7 Air Changes per hour at 50 Pa (7 ACH50) or less to pass the2009 IECC. ACH = Air Changes per hour—a measure of how many times the air within the conditioned space (normally a house) is replaced, given the amount of flow measured and the volume of the space. Measuring Air Changes per hour requires the measurement of the test airflow in CFM required to achieve 50 Pa and the building volume. CFM = Cubic feet per minute—measurement of volumetric flow rate related to envelope leakage.

Solve Blower Door Test Failure Problems

The Energy Calc Services team will quickly find and seal all problem areas. Using fully approved and/or specified materials, our Techs have the experience to trouble shoot and seal any facet of your building.
To schedule sealing, give us a call!

Schedule A Blower Door Test


Blower Door Test and report average $200
Average price is subject to change. Exact estimate will be provided based on location, design of building, number of HVAC units, and choice of services.
Included With Blower Door Test:

  • Envelope Leakage Test Report
  • House Configuration Documentation Sheet
  • Air Leakage Report - Should blower door test fail to meet code requirements, report is provided free of charge.

Blower Door Time Frame & Procedure

This process will take a minimum of 1 hour and at this time we can perform the test within 2 to 3 days of contact.

  • Visual inspection of the exterior, interior, and attic of the house to make sure that all exterior doors and windows are closed and locked, and all interior doors are open except closets unless they have air or attic access.
  • All combustion appliances will be set to pilot or a setting that will not allow them to come on
  • Set all thermostats to off and verify all other exhaust fans, dryers, rangehood, ceiling fans, or air moving devices are off
  • Document weather conditions, equipment, setup locations, readings, and the setup of the house, during testing to confirm compliance with the standard
  • Installation of frame and blower in an exterior doorway
  • Perform the blower door test by capturing a base line, input required settings, turn the system on, record and calculate the results

Requirements For Blower Door Test

If we performed the initial Energy Load Calculation, we will have all documents on file to perform your Blower Door Test. Simply notify us when you are ready to schedule your test.

If Energy Calc Services did not perform the initial Energy Load Calculation, we require the following documents to perform the Blower Door Test. Instructions and links can be found on our Energy Calculation page.

  • Copy of Energy Calculations Results
  • Architectural Drawings


Blower Door Testing Request


Email the completed Building Information Form, and scaled drawing to

By Phone

Call Brian Bryant at 941-321-7745. We will provide you with an estimate, and set up your testing appointment.