Duct Leakage Test in Lionville, PA

How a Duct Leakage Test Is Conducted

To conduct a proper duct leakage test in Lionville, PA, your technician first seals all supply and return registers except the main return or air handler. A duct blaster fan, carefully calibrated for accuracy, is then attached to the duct opening. It depressurizes the ductwork, allowing leaks to become more noticeable.

The duct blaster, aided by a precision pressure sensor, accurately measures airflow and reveals duct leaks without interrupting activities in your home. A duct leakage test — also called a duct blaster test — locates the points where duct air escapes, helping you implement the right sealing solution.

duct leakage test is straightforward, clean, and designed to be non-intrusive for residents. Most tests in Lionville, PA are done in about 30 to 60 minutes, and the resulting enhancements can support your home’s comfort and efficiency for many years.

How to Measure Duct Leakage

Duct leakage is measured using cubic feet per minute (CFM) per 100 square feet of conditioned floor area. Your technician uses a nanometer to capture subtle pressure changes, allowing accurate measurement of duct air leakage. Understanding this number allows you to highlight problem zones, explore improvement possibilities, and confirm compliance with local energy code requirements in Lionville, PA.

Cost of Excessive Duct Leakage

If you are experiencing high utility bills, uneven temperatures, or frequent HVAC repairs, duct leakage may be the cause. According to ENERGY STAR, an average home’s ductwork loses 20% to 30% of conditioned air through leaks. Outside hot or cold air leaking into your system puts extra strain on your HVAC unit, raising energy bills and decreasing comfort.

Overworked equipment also increases the likelihood of breakdowns and drives up repair costs. Proper duct sealing helps maintain the long-term health of your HVAC system, extending its lifespan and reducing ongoing maintenance needs.

Duct leaks can also allow the entry of dust, mold spores, moisture, and a range of contaminants into the duct system. This can make allergies worse, impact indoor air quality, and result in costly structural damage behind walls or ceilings as time passes.

How to Properly Seal Ductwork in an Old Home

The 2015 IRC/IECC specifies that newly constructed homes must use fully sealed duct systems with modern, efficient materials such as mastic, foil tape, and insulation. But what about leaks that lie far within enclosed wall or ceiling spaces?

Aerosol sealing technology (AeroSeal) is used to address openings concealed inside duct systems. To complete this method, all vents are closed off except for one access opening. The HVAC system is isolated, and a machine is linked to the duct system. It pressurizes the ducts and sends a fine aerosol sealant through the system, closing small gaps that normal sealing approaches can’t reach.

This method works efficiently for small to medium leaks. However, larger gaps usually require manual sealing using mastic and tape. Technicians conduct a duct leakage test before and after aerosol sealing to measure how much the leakage has been reduced and ensure the treatment is successful.

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 changes between heating and cooling during the year, the ducts naturally expand and shrink. Over time, this movement makes the joints loosen, forming gaps and leaks — meaning a duct leakage test is advised for both new and older homes in Lionville, PA.

Many energy auditors detect leaks by checking the duct surfaces by hand and using a small tool to measure joint gap width. If your duct system wasn’t sealed using mastic and approved tape, there is a strong chance that air leaks are occurring.

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

To achieve a passing duct leakage result, your system must read under 4 CFM per 100 square feet with the air handler installed, or 3 CFM per 100 square feet without the air handler. For new construction, passing the duct leakage test is a necessary step before securing an occupancy certificate.

If your home in Lionville, PA fails a duct leakage test, you are probably spending more than you should on heating and cooling — while also putting long-term stress on your HVAC system. Meeting the 3–4 CFM requirement is necessary not only for meeting code standards but also for ensuring strong energy efficiency and indoor comfort.

Your technician will also share expert recommendations for fixing leakage problems, helping you achieve a passing score, save on utilities, and improve home performance.

Local Energy Audits — affordable duct leakage test in Lionville, PA

Local Energy Audits proudly serves homeowners, contractors, and builders throughout Lionville, PA and nearby regions. We specialize in assessing duct leakage and energy inefficiencies with blower door tests and duct leakage tests. Whether it’s a new build or a current home, we’re here to support you.
If you’d like to schedule a test, call us during business hours or contact us online to request an appointment.