Duct Leak Testing in Low Country, South Carolina

A duct leakage tester measures the airtightness of forced air heating, ventilating and air-conditioning ductwork. This diagnostic tool consists of a calibrated fan for measuring an air-flow rate and a pressure-sensing device to gauge the pressure created by the fan flow. The combination of pressure and fan-flow measurements determine the ductwork's airtightness. The airtightness of ductwork helps in efforts to boost energy efficiency within the HVAC system.

Methods For Conducting a Duct Leakage Test

  • Blower door only (not recommended)
  • Blower door and pressure pan (for diagnostic purposes only)
  • Duct leakage tester and blower door together (most common method)
  • Flow hood

Basic Principles for Using a Duct Leak Tester

  • Let a calibrated fan pressurize the duct system.
  • Measure the airflow through the fan with the duct system at pressure.

When you’re testing for air-tightness, each cubic foot of air that leaks out of the duct system must be made up by a cubic foot of air blown in by the fan. Once you have measured the amount of air moving through the fan, you have quantified the duct leakage at the test pressure.

Standard Pressure for Duct Leak Testing

For duct leakage testing, the standard pressure used is 25 Pascals. That is close to the operating pressure of a typical duct system. Example: When we measure 120 cubic feet per minute of duct leakage at 25 Pascals (written as 120 cfm25), that number is a good estimate of how much air leaks out of the duct system while it is operating.

Two Types Of Duct Leaks

There are two types of leaks, benign and malignant. Malignant leaks require immediate attention. They send conditioned air into unconditioned spaces or suck the unconditioned air into the HVAC system. Either one will damage your indoor air quality and could harm your HVAC unit.

Benign leaks remain inside the conditioned space and don’t exact an energy penalty.

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Separate Leak Tests are Needed

These two kinds of duct leakage require two different types of tests. The malignant leaks occur in ducts that are outside the conditioned space, so the most important test is called an “outside leakage test.” The other test is called the “total leakage test.”

Let Ocean Air Cooling & Heating Find Your Duct Leaks 

To fix duct leaks, you must find them first. Ocean Air Cooling & Heating will help you conduct the ideal duct leakage test for your home in Low Country, South Carolina. We provide premium HVAC services at a customer-friendly cost. Contact us at 843-508-2620 for a free estimate when it is time to test for duct leaks at your home. 

Systems We Serve

  • ruud
  • rheem
  • goettl
  • westinghouse
  • trane
  • carrier
  • lennox
  • bryant
  • amana
  • goodman
  • york
  • comfortmaker
  • heil
  • american standard
  • coleman
  • tempstar