Duct Leakage Test in Hillsborough, NJ

How a Duct Leakage Test Is Conducted

To set up a duct leakage test in Hillsborough, NJ, the technician begins by sealing all supply and return registers, leaving only the air handler or main return open. A specially calibrated fan known as a duct blaster is then put in place at the opening. It depressurizes the ductwork so escaping air can be accurately identified.

The duct blaster collaborates with a precision pressure sensor to evaluate airflow and locate leaks throughout the ductwork without disturbing your household. A duct leakage test — frequently called a duct blaster test — reveals air escape points in your ducts, guiding you toward the best sealing options.

duct leakage test is quick, clean, and non-intrusive for residents. Most tests in Hillsborough, NJ take between 30 and 60 minutes, and the improvements they deliver can elevate comfort and efficiency for years ahead.

How to Measure Duct Leakage

Duct leakage is quantified in cubic feet per minute (CFM) for each 100 square feet of conditioned living space. Your technician uses a nanometer to read small pressure variations, helping determine the volume of air escaping through the ducts. Understanding this number helps you identify problem areas, evaluate potential improvements, and determine whether your home meets local energy code requirements in Hillsborough, NJ.

Cost of Excessive Duct Leakage

If your home suffers from costly utility bills, uneven comfort levels, or persistent HVAC repairs, duct leakage may be contributing. According to ENERGY STAR, many homes lose as much as 20% to 30% of conditioned air through duct leaks. If hot or cold air from outdoors enters your system, your HVAC works harder than necessary, causing energy costs to rise and comfort to fall.

Overworked equipment also produces more frequent issues that require costly repairs. Proper duct sealing helps support the long-term durability of your HVAC system, lengthening its lifespan and minimizing ongoing maintenance demands.

Duct leaks can also allow the entry of dust, mold spores, moisture, and a range of contaminants into the duct system. This can amplify allergy problems, impact air quality indoors, and slowly create costly structural damage behind walls or ceilings.

How to Properly Seal Ductwork in an Old Home

The 2015 IRC/IECC requires all newly constructed homes to have fully sealed ductwork with modern, energy-saving materials such as mastic, foil tape, and insulation. But what if the leaks you’re dealing with are deep inside the walls or ceilings?

Aerosol sealing technology (AeroSeal) enables effective sealing of leaks hidden inside ducts. To use this method, technicians seal all vents except one access point. The HVAC system is isolated, and a machine is hooked up to the duct system. It pressurizes the ducts and applies a fine aerosol sealant that fills tiny openings where standard sealing cannot reach.

This method is ideal for small to medium leaks. However, any large openings will still need manual sealing with mastic and tape. Technicians test the ducts for leakage before and after aerosol sealing to determine the reduction level and verify success.

Common Areas of Duct Leakage

The most common spot where air escapes in duct systems is the joints. Ductwork features several metal pieces pressed together using tight fittings and metal bands, though these areas are seldom airtight.

As your HVAC system runs through seasonal heating and cooling, the ducts experience ongoing expansion and contraction. Over time, this movement loosens the joints, causing gaps and leaks — which is why both new and older homes in Hillsborough, NJ should consider a duct leakage test.

Many energy auditors inspect duct leakage by feeling the ducts and using a small tool to determine how wide the gaps are between joints. If your duct system was not sealed with mastic and approved tape, there’s a high likelihood that air is leaking.

What Is an Acceptable Amount of Duct Leakage per Energy Code?

To achieve a passing duct leakage result, your system should stay under 4 CFM per 100 square feet with the air handler attached, or 3 CFM per 100 square feet without it. For new construction, homes are required to pass a duct leakage test before an occupancy certificate can be issued.

If your home in Hillsborough, NJ doesn’t pass its duct leakage evaluation, you’re likely paying more for temperature control — and contributing to long-term HVAC strain. Meeting the 3–4 CFM requirement is crucial not only for passing code but also for maintaining your home’s overall energy efficiency and comfort.

Your technician will also provide professional insights on resolving leakage issues so you can achieve a passing score, lower your utility costs, and optimize home performance.

Local Energy Audits — affordable duct leakage test in Hillsborough, NJ

Local Energy Audits proudly serves homeowners, contractors, and builders throughout Hillsborough, NJ and nearby regions. We specialize in locating and diagnosing duct leakage and energy inefficiencies through blower door and duct leakage tests. Whether your home is newly built or older, we’re here to help.
If you’d like to schedule a test, call us during business hours or contact us online to request an appointment.