Fresh-air Filters: Clean Up the (Cab) Environment

Do your part for the environment inside the cab of your truck or heavy equipment: regularly inspect and replace the fresh-air intake filter.

The fresh-air intake filter not only captures dust, dirt, and other airborne particles that can irritate the driver, it stops them from interfering with the performance of the heater and air conditioner. Without an effective filter, particles of dirt and dust can end up sticking on the evaporator core.

“You may not be able to absorb as much heat out of the cab as you would if the core were clean. As a result, your air conditioner won’t be as effective as it should be,” says Robert Gardiner, marketing manager at Red Dot Corp. Based in Seattle, Red Dot designs and builds heating and air-conditioning systems, components, and replacement parts for heavy trucks and other commercial vehicles.

Most vehicles have one or more fresh-air intake filters made of pleated paper, the same type of media you’d find on the air filter in an engine. Dirt and debris settle into the folds and build up from there. Some filters, like HEPA (High-Efficiency Particulate Air) filters, are made of high-density pleated paper and capture extremely small particles that might be harmful to people with allergies or asthma. Others are made of open-cell foam. Charcoal impregnated filters can help trap particles from cigarette smoke and neutralize the odor.

The first sign of a plugged filter is a feeling that not enough air is coming through the vents. “The operator complains about low fan speed, but it turns out a plugged filter is restricting the airflow,” says Gardiner. “Air can’t move through the plugged filter, which is why he’s not feeling the strong, steady flow of cool air.”

A quick sweep with a vacuum cleaner may remove loose particles from a dirty paper filter, but you’re best to start fresh with a new one, taking care to install it properly. If you have an open-cell foam filter, you can wash it carefully using soapy water.

Check your owner’s manual for the recommended inspection interval for your cab’s fresh air filter. That probably means checking the filter every three months—at every oil change, for example—and replacing it with a filter that meets the original-equipment spec.

So be environmentally conscious. Inspecting and replacing the fresh-air intake filter on your truck is one of the easiest things you can do to improve air quality where it counts most: in the environment where you work and live every day.