Could the shift to better filters mean that they could cause problems with inadequate airflow or greater fan energy use? Are all high-MERV filters equal, or do some have less pressure drop than others? How much better are 2- and 4-inch-thick pleated filters than 1-inch filters? Some tests were run to answer these questions.

Measuring duct static pressure is a fundamental part of diagnosing how a duct system is performing. It’s kind of like getting your blood pressure tested when you go to the doctor.

John Logue was stumped. The contractor designs and installs 55 to 80 HVAC systems a year, but he had never run into this situation - a customer complaining that water was coming out of the homeowner's supply grilles.

Many building codes in the southeastern United States call for increased attic and crawl space ventilation to fight moisture and related IAQ problems. Craig DeWitt, Ph.D., P.E., challenged that notion at the South Carolina Association of Heating and Air Conditioning Contractors' (SCAHACC's) 2003 Indoor Comfort Science Conference.

Sometimes it's all in the tools you use.

During the energy crisis of the early 1970s, heat pump systems became popular for many commercial and residential hvac applications because of their lower first cost and potentially energy-saving performance.

The key is to size, select, and install them correctly.