Duct Leakage Testing: Why It Matters for HVAC Performance & Energy Efficiency
Duct leakage is one of the most common — and most overlooked — issues affecting HVAC system performance.
Even small leaks in supply or return ducts can lead to:
For commercial, industrial, and institutional buildings, leakage testing is a key part of verifying system performance and ensuring compliance with design requirements.
1. What Is Duct Leakage Testing?
Duct leakage testing measures the amount of air escaping from the duct system under controlled pressure conditions.
During the test, a calibrated fan is connected to the ductwork to pressurize the system. The equipment measures:
This test is required in many commissioning and TAB processes.
2. Why Duct Leakage Matters
✔ Energy Efficiency Loss
When air escapes from ducts, HVAC equipment must work harder to deliver required airflow, increasing energy consumption.
✔ Poor Temperature Control
Leaky ducts lead to inconsistent temperatures, causing hot/cold spots and occupant complaints.
✔ Ventilation Issues
Air leaks reduce fresh air delivery and weaken exhaust systems — especially important for hospitals, labs, and clean spaces.
✔ Increased System Strain
Fans, dampers, and VAV boxes may operate outside normal ranges because of unaccounted airflow losses.
3. Common Causes of Duct Leakage
Common causes include:
In commercial buildings, leakage is often found at:
4. Benefits of Performing a Leakage Test
✔ Improved HVAC Performance
Verified duct tightness means accurate airflow delivery to all zones.
✔ Reduced Operating Costs
Leaky ducts waste conditioned air, increasing heating/cooling bills.
✔ Better Indoor Comfort
Consistent airflow supports proper temperature control and ventilation.
✔ Compliance With Industry Standards
Many specifications reference testing based on:
Conclusion
Duct leakage testing is a simple but powerful diagnostic tool that helps identify airflow losses, optimize HVAC system performance, and reduce energy waste.
For building owners and facility managers, it is one of the most cost-effective tests to ensure reliable long-term operation.
Green Tech Air Balancing provides professional leakage testing using approved industry methods for commercial, industrial, and healthcare facilities.
