Blower Door Test Notice

Mandatory Residential Air Infiltration (Blower Door) Testing

In Pinellas County, Florida Building Code R402.4.1.2 requires all new residential buildings or dwellings need to have a blower door test before they can be issued a Certificate of Occupancy. Buildings with improper air flow can waste a substantial amount of energy on heating and cooling; in Florida, it’s estimated that 30% of the energy used for cooling a building is wasted by air leaking between the inside and outside.

By conducting a blower door test, we can ensure that a new building is airtight enough to meet energy design requirements.

For more information, review the 2016 code supplement or contact us at (727) 464-3888.

Test Process

For a blower door test, a house is closed up from the outside, including windows, doors and fireplace dampers. A frame with a blower fan is mounted in one exterior door, and it sucks air out of the house at a negative pressure difference of 50 Pascals (ach50). The frame is equipped with airflow manometers — devices that measure the volume of air being removed from the house.

If the volume of air being removed per hour is between 3 and 7 times the volume of air inside the house, the test passes. Less than 3 implies not enough outside air can enter into the house, so indoor air quality will be poor; more than 7 means that too much air is leaking out of the house and wasting an unacceptable amount of energy.

Approved Testers

Blower door testing can be performed only by:

  1. Anyone defined under FS 553.993 (5) or (7) who is:
    1. An energy auditor or energy rater.
    2. Currently certified through the Residential Energy Services Network (RESNET) or the Building Performance Institute.
  2. Anyone licensed under FS 489.105(3)(f), (g) or (i) who is a:
    1. Class A air conditioning contractor.
    2. Class B air conditioning contractor.
    3. Mechanical contractor.
  3. Anyone otherwise approved by the Building Department.

To become registered with the Building Department, you must submit proof of Pinellas County Construction Licensing Board (PCCLB) registration or submit the following:

  1. Proof of professional license and/or certification.
  2. Proof of liability insurance ($100,000 bodily injury/$25,000 property).
  3. Proof of workman’s compensation insurance or an exemption.
  4. Proof of business tax receipt for your company (if applicable).

In order to get a Certificate of Occupancy, you must submit a blower door test report to the Building Department. It must verify 7 air changes per hour or fewer and be signed by the approved, registered tester.

Additional Resources

For more information, visit:

Building Energy Codes Program
Building Science Corporation
Building Codes Assistance Project