Blower Door and Duct Leakage Testing in the Lehigh Valley
Find the cause. Measure the difference.
Blower-door testing, duct-leakage testing and thermal imaging reveal how your home performs—so your next improvement starts with clear evidence.
Measure before you improve — it’s the science behind comfort.
Why Testing Matters
Many comfort and energy problems are caused by hidden air leakage or duct losses. Without testing, improvements like insulation or HVAC equipment upgrades can miss the real issue. Testing reveals~ • How much air leaks through the building envelope • How much heating and cooling escapes through ductwork • Where improvements will make the biggest difference That’s why we measure two critical systems: • The building envelope • The HVAC distribution system
Blower Door Testing
We use industry-leading Retrotec equipment to capture defensible, repeatable performance data.
During testing, we control the home to standard reference pressures (typically ±50 Pascals) and document:
CFM50 — total air leakage at test pressure
ACH50 — air changes per hour normalized to home volume
Equivalent Leakage Area (EqLA) — cumulative size of all leaks
Pressure differentials (Pa) — room-to-room and zone diagnostics
Baseline & induced pressures — to separate natural from forced leakage
Real-time flow tracking — stabilized and averaged for accuracy
This system automatically maintains test pressures, which lets us concentrate on collecting the data, confirming leakage locations with infrared imaging and clearly explaining what the numbers mean for comfort and energy performance.
Benefits
• Locate hidden air leaks
• Diagnose comfort problems
• Verify energy improvements
• Meet new-construction code requirements
These metrics help determine how efficiently your home retains heating and cooling.
Duct Leakage Testing
Even high-efficiency heating and cooling systems can lose significant performance when duct systems leak.
Using state of the art duct-testing equipment including the Retrotec DM32X and DucTester system, we measure total duct leakage in CFM25, the industry standard for HVAC leakage testing.
This reveals whether conditioned air is escaping into:
• Attics
• Basements or Crawlspaces
• Garages
• Building or structual cavities
Testing allows targeted improvements that restore airflow and system efficiency.
Different Tests Reveal Different Clues
Blower door testing shows how much air is leaking through the home’s shell.
Duct leakage testing shows how much heated or cooled air may be escaping through the duct system before it reaches the rooms it was meant to serve.
Infrared imaging adds a visual layer by showing temperature patterns that may point to missing insulation, hidden air movement, or comfort-related trouble spots.
When used together, these tests help us explain what the home is doing, where comfort and energy are being lost, and which improvements are likely to matter most.
A Clearer Picture of How Your Home Performs
Think of these measurements as a health check for your home. Just as a doctor uses vital signs to understand the body, these diagnostics help us understand how air moves through your house.
During testing we measure several key metrics that describe how air moves through your home.
Common measurements we use
- • CFM50 – The total volume of air leaking through the home under test conditions.
• ACH50 – How many times the entire air volume of the home is replaced in one hour during the test. - • Equivalent Leakage Area (EqLA) – The combined size of all air leaks expressed as a single opening.
- • CFM25 (Duct Testing) – The amount of air escaping from the HVAC duct system.
- • Delta T (∆T) – The temperature difference between two places. In home testing, it helps show where heat is being lost, gained, or unevenly distributed through the home.
Who Benefits From This Testing
Homeowners Improving Comfort and Efficiency
Ideal for homeowners who want to identify hidden air leaks before investing in insulation, HVAC equipment, or other upgrades. Our testing reveals attic bypasses, duct leakage, and pressure imbalances that drive energy waste and uneven temperatures.
Homes with Forced-Air Heating and Cooling Systems
Duct leakage testing is especially valuable for homes with forced-air systems. It measures how much conditioned air escapes before reaching living spaces, helping restore airflow balance and system efficiency
New Construction and Builders
Pennsylvania’s 2021 IECC energy code requires new homes to meet airtightness targets of ≤3 ACH50. Duct leakage testing is also mandatory for forced-air heating and cooling systems, with allowable leakage generally ranging from 3–8 CFM per 100 sq. ft. of conditioned floor area.
Project Probono provides calibrated duct leakage and blower door testing, documentation, and certification to help builders verify compliance, satisfy code requirements, and pass inspection.
Homes Preparing for Energy Upgrades
Testing is the first step before major improvements such as attic air sealing, insulation upgrades, or duct sealing. Measured diagnostics ensure improvements address the real sources of energy loss rather than guessing.
Trusted. Vetted. Connected.
Leaders in Building Science and Home Performance
Our credentials and partnerships reflect nearly three decades of proven results. From national certifications to local utility alliances, these organizations represent the standards and programs that define quality work — and we’re proud to meet or exceed each one.
