Duct Diagnostics: 4 Steps To A More Efficient System

If your cooling or heating equipment isn’t performing up to par, it may have nothing to do with your A/C unit or furnace. The trouble’s more than likely some distance away, out of sight in the attic or the crawl space where your ductwork tips runs. Proper duct diagnostics performed by an HVAC pro will reveal problems with duct leakage, inadequate ductwork insulation or inefficient design. Because of the hidden nature of ductwork, few homeowners ever even see duct problems, much less effectively diagnose them. It’s a job for a trained technician with specialized equipment. 

Here are the four basic steps of duct diagnostics:

• Visual inspection. Your technician will look for disconnected segments, rust, corrosion and signs of leakage. Inadequate or missing insulation will be noted, as well. Design problems, like the use of structural spaces inside walls and ceilings to convey air instead of proper ductwork, are major efficiency drains, too.
• Duct pressure test. The technician will utilize a fan device to measure the amount of airflow needed to pressurize the ductwork. This figure allows an estimate of the degree of leakage throughout the system. Your technician will also want to know how much of the leakage occurs within the thermal envelope of the home and how much is outside in unconditioned zones like the attic.
• Airflow measurement. Leaks alone don’t degrade duct function. The rate of leakage in proportion to the airflow through the system is important. Low airflow at the blower is a major cause of sub-par performance. Specialized equipment to measure airflow helps the technician determine the efficiency of blower operation in relation to factors like leaks, system design and air friction.
• Corrective measures. After the diagnostics are finished, the HVAC professional will present options for repair. Usually these will include reducing duct leakage to less than 10 percent in relation to fan flow rate and installing or increasing duct insulation to achieve an R-Value (thermal resistance) of 8.

Since 1969, AirTro Inc.has kept homeowners in greater L.A. and Orange counties comfortable. If you suspect your ductwork of inefficiency, let our trained technicians evaluate the situation. Contact us today for expert consultation!

Our goal is to help educate our customers about energy and home comfort issues (specific to HVAC systems).  For more information about duct diagnostics and other HVAC topics, visit our website.

Air-Tro Inc. services the greater Los Angeles area as well as the metro areas of Riverside and San Bernardino County.