Clean Up The (Cab) Environment

Staff | September 28, 2010

Do your part for the environment inside the truck: regularly inspect and replace the fresh-air intake filter on your cab's heating, ventilation and air conditioning system.

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. It's a common problem when the truck operates in dusty job sites.

"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 can be," says Mark Williams, supervisor of warranty and product support at Red Dot Corp. based in Seattle.

Most trucks 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.

For a lot of truck operators, the first sign of a plugged filter is a feeling that not enough air is coming through the vents. "The operatorcomplains about low fan speed, but it turns out a plugged filter is restricting the airflow," says Williams. "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. To install a replacement filter, look for an arrow to indicate the direction of the airflow. If the filter has aluminum mesh to give it shape and substance, the mesh should face the downstream side.

You can wash an open-cell foam filter, Williams says. "Use soapy water, nothing harsher, and wash in the direction of the airflow, so you're flushing water from the air-outlet side to the air-intake side of the filter," he explains.

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 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.

Red Dot designs and builds heating and air-conditioning systems, components and replacement parts for heavy trucks and other commercial vehicles.