Checking and Replacing Your A/C Filter

How to Check and Replace Your Air Conditioning Filter

Photo courtesy of mbschn

The filter is one of the most important components of the air conditioning unit. Regularly replacing the filter (every few months or so) not only helps the air conditioner to continue running efficiently - by keeping dust and debris out of the unit's inner workings - but doing so also ensures you're keeping allergens and irritants out of the circulating indoor air. Follow these simple instructions and you'll discover how easy and how fast changing the A/C filter can be.

1) Locate the Filter

This seems like a logical first step. First, you have to find it. Each type of air conditioning unit has a different location for the air filter. The filter may be located near the furnace and filter compartment or near the thermostat. The filter is covered by a metal guard that slides out and square vented panel which will need to be unscrewed for access.

2) Determine the Filter Size

Different air conditioning units use different size filters. The size for the filter should be located on the side and will appear in inches.

3) Choose a Replacement Filter

There are several different types of filters to choose from. 

• Fiberglass filters are inexpensive and attract dust, but need to be replaced every 30 days.

• Pleated filters can be replaced less often at 90 days, but may easily become clogged with dust before then.

• HEPA (high efficiency particulate air) filters work well for households with family members who suffer from allergies from pet dander, mold and other irritants.

• Electrostatic filters remove dust and debris, but are also effective for removing odors from smoke and mildew. These filters are reusable and just need to be cleaned with water on a regular schedule.

The chosen air filter should fit in the air conditioning unit snugly and maintain the efficiency of the unit.

4) Identify Air Flow Direction

In order to make sure that the filter is being replaced correctly, note the direction of the air flow on the side of the old filter. Using a permanent marker to draw the air flow direction on the metal guard offers an easy reference for future filter changes.

5) Replace the Filter

Take out the old filter and slide in the new one, keeping in mind the air flow direction. The filter should fit snugly for maximum efficiency.

6) Replace the Metal Guard and Panel

Slide the metal guard back to its original position and screw the vented panel back into the wall.

When to Change the Air Conditioning Filter

It is recommended that most air filters be changed or cleaned once every 30 days to once every three months. However, the replacement rate really depends on a number of factors.

For example, the more efficient filters capture more dust particles and indoor contaminants than less efficient filters. Thus, they need to be replaced or cleaned more often to keep the air conditioning unit working efficiently.

Finally, homes that have pets or family members that smoke indoors will also benefit by replacing their air conditioning filters more often. Further, if a family member suffers from allergies caused by pollen or dust, replacing the filters more frequently will reduce the amount of indoor air pollutants in the home.

-- Doug