How to Make an AC Evaporator Coil Filter

Filters in A/C units need to be replaced often to ensure optimum performance.

In an air conditioning system the evaporator coil provides the cooling effect. A fan blows air over the evaporator coil, and the coil cools the air. There is usually a filter, which filters the air from the fan and prevents the coil from getting dirty. Replace the filter if it is dirty or malfunctioning. A malfunctioning air filter will lead to ineffective cooling. If you find your central A/C is not as effective as it once was, you can make a replacement air conditioner filter using low density foam.

Things You'll Need

• Screwdriver (optional)
• Measuring tape
• Low density foam
• Scissors

Instructions

1. Locate the filter housing on the central A/C unit; it will be labeled and should pull out like a drawer. Some covers clip off, while others unscrew. Measure the width and length of the evaporator filter you remove.

2. Cut out a piece of very low density foam to the measurements of the filter you have removed. Low density foam allows air to pass through, while capturing dust particles.

3. Open the cardboard frame housing the old filter. Remove the filter element and discard it. Insert the low density foam carefully into the cardboard housing.

4. Place the new filter and housing back into the A/C unit in the reverse manner of the way you removed the old filter.

Tips & Warnings

• Check the condition of your evaporator coil filter regularly for any problems or blockages.

• Ensure that the AC unit is not receiving power when replacing the filter.

• Take care not to damage any piping or other components when replacing the AC filter.

References

• "Boilers, Evaporators, and Condensers"; S. Kakac.; 1991

Resources

• Air Conditioning Filter: Air Conditioner Cased Evaporator Coil