Bottom Line
Keeping your cool

Special to Land Line


It doesn’t matter how swank your cab is. If it’s a scorching 110 degrees outside and your air conditioner is on the fritz, you’re going to be one unhappy camper.

There are a few tips and tricks to making sure your air conditioner doesn’t shoot craps in the middle of the night.

A simple start is to 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, hair, lint and other airborne particles, but also stops them from interfering with the performance of the air conditioner. A plugged filter can block the airflow through the evaporator, which is responsible for absorbing the heat in the cab and moving it outside, and can give you the feeling that not enough air is coming through the vents.

 “You may think there’s something wrong with your fan when in fact a plugged filter is restricting the airflow,” said Mark Williams, supervisor of warranty and product support at Red Dot Corp., which supplies HVAC products.

Checking and replacing an air filter is a job you can do yourself. Here’s what you should know:

  • Most trucks have one or more fresh-air intake filters made of pleated paper, the same type of material on the air filter in an engine. Some filters, including HEPA filters, are made of high-density pleated paper and capture extremely small particles that can irritate people with allergies or asthma. Others are made of open-cell foam and use charcoal to help trap particles from cigarette smoke and neutralize the odor.
  • Hold a flashlight up to the pleats of a paper filter. If you can’t see the beam on the other side, start fresh with a new one. If you have a foam filter, you can try cleaning it with soapy water, but nothing harsher. You want to wash in the opposite direction of the normal airflow so you don’t force particles back into the filter mesh, where they can become stuck.
  • When you 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.
  • See your owner’s manual for the location and recommended inspection interval for the fresh air filter. In general, check the filter every three months (use your oil-change interval as a guide) and replace it with a filter that meets the original-equipment spec.

Your condenser also needs routine attention. It sits behind the grille and has all those fins on it: the ones that get plugged with bugs and feathers and dirt, or that bend over when you hit them with a pressure washer.

 Those fins are vital to the performance of your air conditioner, because the air flowing over them removes heat from the refrigerant that circulates inside the condenser.

The next time you have a moment, inspect the condition of the fins on the condenser, suggests Frank Burrow, warranty and product support manager for Red Dot Corp.

 “Debris can collect on the face of fins and tubes and act as a thermal barrier, making it hard for the condenser to shed heat out of the cab and put it into the atmosphere,” Burrow says.

At the same time, check to see that the fins are straight. Bent fins – typically caused by pressure washing – disrupt the airflow across the condenser, which hurts system performance. Your HVAC parts supplier can provide you with a fin comb.

 “If the condenser is plugged or those fins are bent, the refrigerant will come back around hot, and the system won’t blow cold air like you expect,” says Burrow. “A routine inspection will highlight the need to clean the condenser and comb the fins.” LL