What is Duct Leakage Testing?
Duct Leakage Testing is a method used to measure the amount of air leakage in a ductwork system—usually for HVAC (Heating, Ventilation, and Air Conditioning) systems. It helps verify that the ducts are properly sealed and that conditioned air is not being lost through gaps or cracks.

Why Is It Important?
Energy efficiency: Leaky ducts can cause significant energy loss.
System performance: Reduced airflow affects heating/cooling efficiency.
Indoor air quality: Leaks can draw in contaminants from unconditioned spaces.
Compliance: Required by many building codes and certifications (e.g., LEED, ASHRAE, SMACNA).

How Is It Performed?
Seal all supply and return registers with tape or plastic covers.
Connect a duct tester fan to the system—either at the air handler or a large register.
Pressurize or depressurize the duct system using the fan.
Use a pressure gauge and flow meter to measure:
CFM25 (Cubic Feet per Minute at 25 Pascals): How much air is leaking at a test pressure of 25 Pa.
Compare results to allowable leakage thresholds.

Types of Duct Testing
Rough-in test: Done before the drywall is installed.
Final test: Done after construction is complete.
Total leakage vs. leakage to outside: Some tests only count leaks to the outside, others include total leakage.

Standards & Guidelines
SMACNA: Sheet Metal and Air Conditioning Contractors’ National Association
ASHRAE 90.1: Energy standard for buildings
IECC: International Energy Conservation Code

Summary
Duct Leakage Testing is crucial for ensuring that HVAC systems operate efficiently, safely, and in compliance with energy and building codes. It helps minimize energy waste, maintain comfort, and ensure air quality.
Would you like a sample test report or diagram of how the testing setup looks?