Running your furnace, central air, or heat pump probably constitutes a big part of your utility bill. But it’s a small, often inexpensive part—the air filter—that keeps these heating and cooling ...

PRESSURE TAPS: Filter driers can be purchased with Schrader valves (pressure taps) on their inlets and outlets (left), or just on the inlet (right). A pressure drop of more than 2 psi measured with ...

While as little as 20 years ago, cabin air filters were only found in higher end cars, today pretty much anything on four wheels has one of these paper elements to help keep air-borne impurities out.