What to know about Florida’s Blower Door testing requirement for building code
As of July 1st, 2017, all new residential homes in Florida must pass a Blower Door (also known as House Infiltration) test to meet energy code. In order to help builders in this transition, here is a list of the most frequently asked questions regarding Florida’s Blower Door test mandate.
#1) Where are the Blower Door testing requirements located?
Section 402.4.1.2 of the Florida Building Code, 5th Edition 2014 Energy Conservation. Click here to view this section of the code.
#2) What is the specific requirement?
Each home must have 7 air changes per hour (7 ACH50) or less in order to pass the Blower Door test.
The Blower Door test simulates the following: If a home has wind blowing against it at 20 miles per hour, the total volume of air within the house would exchange with outside air 7 times. The 20mph wind is equivalent to 50 Pascals (Pa) pressure difference that is simulated using the Blower Door Fan during the test. All homes are tested at 50 Pa pressure difference to allow for comparisons to be made between homes/structures, no matter the size or plan type.
#3) Does the Blower Door testing requirement apply to multi-family construction?
Yes, buildings 3 stories or less must abide by the residential energy code.
#4) Is the Blower Door test difficult to pass?
If the home meets the air sealing requirements found in table R402.4.1.1 (below), passing the test is easy.
#5) How much does the Blower Door test cost?
On average, Blower Door testing costs around $150.00 per test.
#6) How long does the test take to complete?
Testing takes approximately 30 minutes to complete after set-up.
#7) When should the test be performed?
Once the house is complete, all weather-stripping is installed, the home has power, water, and no holes in the walls.
#8) How do I receive the results/what do I do with the results/ what paperwork do I provide to the Building Official?
The provider typically leaves the results on-site for the builder, but some providers can also provide the results electronically.
#9) What does the Blower Door test tell you?
The Blower Door test measures how leaky or drafty a home will be, which can contribute to homeowner discomfort. Also,the tighter a house is, the better control we can have over pollutants that enter the house.
#10) Is Mechanical Ventilation (fresh air) required?
If a home has less than 3 ACH50 or 3 air changes per hour for the Blower Door test then mechanical ventilation is required.
#11) Why is the 3 ACH important in determining the need for mechanical ventilation?
When a home has less than 3 ACH50, there is little air exchanged through the home while under natural conditions. In these cases, it has been found that homes have increased humidity and the air can become stagnant. The 3 ACH50 is the industry standard for requiring mechanical ventilation.