What Is a Duct Leakage Test?
A duct leakage test measures how much air leaks from your HVAC duct system. A certified HERS Rater uses a calibrated “duct blaster” fan to pressurize the duct system and measures the amount of air that escapes through leaks in joints, connections, and fittings. The result is reported as CFM25 (cubic feet per minute at 25 Pascals of pressure).
Is Duct Leakage Testing Required in Massachusetts?
Yes — for new construction with ducted HVAC systems. Under the MA Stretch Code 2021, all new residential construction in Massachusetts with forced-air heating or cooling systems must pass a duct leakage test before receiving a certificate of occupancy. The test must be performed by a RESNET-certified HERS Rater.
What Is a Passing Duct Leakage Test Result in Massachusetts?
The MA Stretch Code 2021 requires that total duct leakage not exceed 4 CFM25 per 100 square feet of conditioned floor area. For example, a 2,000 sq ft home must have total duct leakage of 80 CFM25 or less. Leakage to outside (duct leakage to outside, or “Qto”) must be 4 CFM25 per 100 sq ft or less.
How Much Does Duct Leakage Testing Cost in Massachusetts?
Duct leakage testing in Massachusetts typically costs $350–$600 as a standalone test. It is usually included as part of a comprehensive HERS Rating package ($1,850–$2,500) along with blower door testing, plan review, and energy modeling. Bundling the tests together is more cost-effective than scheduling them separately.
What Causes Duct Leakage Test Failures in Massachusetts?
Common causes of duct leakage failures include: poorly sealed duct connections at the air handler, registers, and trunk lines; missing mastic sealant or metal tape at joints; supply and return boots not properly sealed to drywall; ductwork installed in unconditioned spaces (attics, crawlspaces) without proper sealing; and flexible duct connections that have come loose.
Book a Duct Leakage Test in Massachusetts
HERS Rating Company provides certified duct leakage testing throughout Massachusetts. We coordinate the test to fit your construction schedule and provide a written report for your building inspector. Contact us for a free quote.
Related Services in Massachusetts
HERS Rating Company is a RESNET-certified, Mass Save-approved HERS Rater serving all 351 Massachusetts cities and towns.
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Duct Leakage Testing in Massachusetts: Complete Process Guide
Duct leakage testing (duct blaster test) measures how much air escapes from HVAC duct systems. In Massachusetts, new construction must achieve less than 4% total duct leakage to comply with the MA Stretch Code 2021. HERS Rating Company performs duct leakage testing across all 351 Massachusetts cities.
What Happens During a Duct Leakage Test?
A calibrated fan pressurizes the duct system while all registers are sealed. The airflow required to maintain pressure is measured and compared to the total system airflow. Results are reported as a percentage of total airflow. If ducts fail, the installer makes corrections and HERS Rating Company retests. Call 617-584-1809 to schedule your duct leakage test.