Alabama Duct Testing & Verification

April 1st, 2011 – Vestavia Hill’s Building Department became the first building departments in Alabama to start requiring duct testing in accordance with section N1103.2.2 of the 2009 IRC. For remodeling projects or replacements, the only time testing is required is if you modify or replace the majority of the duct work.

October 1st, 2012 – Pell City & Decatur have also started requiring duct testing. Pell City has taken an interesting twist on this & that is if you are replacing the Air Handler you are looking at a mandatory duct test as they consider that a “substantial” modification.

Effective July 1st, 2013 all new construction & systems substantially modified will require testing under the new Alabama Energy & Residential Code.  As a Certified HERS RESNET Rater, ENERGY STAR® Verifier, and one that has spent over 20 years in the trades, not only can we perform & certify the test results, but we can also help you get up to speed with the requirements, and train your employees how to pass on the 1st try.

To schedule a duct &/or envelope leakage test please fill out this form or contact us at (256) 352-7235 — for more on the test, the codes & pricing please scroll down

The Duct Leakage Test:

Duct leakage measurements are used to diagnose and demonstrate leakage & efficiency problems with the system, and certify the quality of the installation. There are three types of test listed in the code below.

  • The “Total Duct Leakage” or “post-construction” test involves sealing up all the registers in the house, hooking up a calibrated fan and pressurizing the duct system to 25 pascals (Pa). By measuring the amount of air flow required (CFM) to keep the ducts pressurized, we know now how leaky said duct system is. (i.e. The tighter the duct system, the less air is needed for the fan to reach the required duct system pressure.)
  • The “Rough-In Test” is basically the same as the Total Duct Leakage Test above except this is done before the drywall goes up. The best thing about this test, is it allows you to make needed corrections before the finishes are installed and is the most popular option. (Please note all the duct runs must be completed & the air handler is installed)
  • The “Leakage to Outdoors Test” involves pressurizing the house (Using a blower door) & duct system (see above) to 25 Pa & measuring how much CFM of air is required to bring the system up to 25 Pa.

The Code:

N1103.2.2 Sealing. Ducts, air handlers, filter boxes and building cavities used as ducts shall be sealed. Joints and seams shall comply with Section M1601.4. Duct tightness shall be verified by either of the following:

1. Post-construction test: Leakage to outdoors shall be less than or equal to 8 cfm (3.78 L/s) per 100 ft2 (9.29 m2) of conditioned floor area or a total leakage less than or equal to 12 cfm (5.66 L/s) per 100 ft2 (9.29 m2) of conditioned floor area when tested at a pressure differential of 0.1 inch w.g. (25 Pa) across the entire system, including the manufacturer’s air handler end closure. All register boots shall be taped or otherwise sealed during the test.

2. Rough-in test: Total leakage shall be less than or equal to 6 cfm (2.83 L/s) per 100 ft2 (9.29 m2) of conditioned floor area when tested at a pressure differential of 0.1 inch w.g. (25 Pa) across the roughed in system, including the manufacturer’s air handler enclosure. All register boots shall be taped or otherwise sealed during the test. *If the air handler is not installed at the time of the test, total leakage shall be less than or equal to 4 cfm (1.89 L/s) per 100 ft2 (9.29 m2) of conditioned floor area. (*Most jurisdictions are not accepting the last test & we do not offer it)

Exception: Duct tightness test is not required if the air handler and all ducts are located within conditioned space.

Additional Info: Dust Testing FAQ’s for Homeowner’s — Common Duct Leakage Area’s & Methods (Note: specific area’s and methods start 1/2 way down)

Cost’s:

Single Package System..................................$210
Leakage to Outside Test (need notification).........add $90
Additional Systems............add $100 each (in same house)
Supply & Return Registers over 10' up...........Please Call 
Rush / Emergency Charge (aka same day charge).......add $75
**On Site Training, Consulting, Diagnostic Time.....$95 hr.
**System Retest.......................Same charges as Above

Discount’s:

  • Negotiated Contract Pricing is available for new sub-divisions and town-home developments, based on size and time frame.

** For each system test we include up to 30 minutes for diagnostic time and to allow additional sealing work to be completed. If additional time is required to pass & our schedule allows, that time will be billed out as Diagnostic & Training Time, saving you a retest fee.

To schedule a duct &/or envelope leakage test please fill out this form or contact us at (256) 352-7235