Starting April 1st, 2011 - Vestavia Hills Building Department became one of the first building departments in Alabama to start requiring duct testing in accordance with section N1103.2.2 of the 2009 IRC.
Effective July 1st, 2013 all new construction & systems substainally modified will also require testing under the new Alabama Energy & Residential Code. As a Certified HERS RESNET Rater, ENERGY STAR® Verifier, and one that has spent 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 first try.
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 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 "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 "Rough-In Test" is basically the same as the Total Duct Leakage Test above. The best thing about this test, is it allows you to make needed corrections before the finishes are installed.
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.
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 *Additional Systems...........add $100 each (in same house) *On Site Training, Consulting, Diagnostic Time......$80 hr. *Supply & Return Registers over 10' up..........Please Call *Rush, Emergency Charge (aka same day charge).......add $75 **System Retest.......................Same charges as Above
Discount's:
- Volume Discount: Starting with your third test in each calendar month, a 10% discount will be applied to all additional testing
- Prepared System Discount: If all supply and additional returns are properly covered for testing, we will discount $25 off each unit test
- Negotiated Contract Pricing is available for new sub-divisions and townhome developments, based on size and timelines
* No Discounts available for these services &/or with restrictions
** If time allows, and the issues are relatively minor; most repairs can be made during the first test & will be billed out as Diagnostic & Training Time - thereby saving you a retest fee
