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Time to Clean Air Conditioners and Heat Pumps

Submitted by Lorene Bartos, UNL Extension Educator

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Summertime is here and the cotton from the cottonwood trees have been blowing through our neighborhoods. As this happens, there can be consequences for air conditioner and heat pump units, the cotton and other debris collects and causes a reduction of air efficiency. Cleaning air filters inside and outside of the home can increase energy efficiency.

How many appliances or pieces or equipment have air filters around your home needing to be changed or cleaned? Let’s start outside with the air conditioner and heat pump units. These need to be cleaned at least once a year and more frequently when debris is in the air.

Depending on what type of unit you have the cleaning may be slightly different. Window or central air units both need attention.

For large units the Nebraska Energy Office suggests:

Clogged, dirty filters block normal air flow and reduce a system's efficiency significantly. With normal air flow obstructed, air bypassing the filter may carry dirt directly into the evaporator coil and impair the coil's heat-absorbing capacity. Filters are located somewhere along the return duct's length. Common filter locations are in walls, ceilings, furnaces, or in the air conditioner itself. Some types of filters are reusable; others must be replaced. They are available in a variety of types and efficiencies. Clean or replace your air conditioning system's filter or filters every month or two during the cooling season. Filters may need more frequent attention if the air conditioner is in constant use, is subjected to dusty conditions, or you have fur-bearing pets in the house.

The air conditioner's evaporator coil and condenser coil collect dirt over the months and years of service. A clean filter prevents the evaporator coil from soiling quickly. In time, however, the evaporator coil will still collect dirt. This dirt reduces air flow and insulates the coil which reduces its ability to absorb heat. Therefore, your evaporator coil should be checked every year and cleaned, as necessary. Outdoor condenser coils can also become very dirty, if the outdoor environment is dusty or if there is foliage nearby. You can easily see the condenser coil and notice if dirt is collecting on its fins. You should minimize dirt and debris near the condenser unit. Your dryer vents, falling leaves, and lawn mower are all potential sources of dirt and debris. Cleaning the area around the coil, removing any debris, and trimming foliage back at least 2 feet (0.6 meters) allows for adequate air flow around the condenser.

Heat pumps also require attention. Suggested routine maintenance can be done by either the homeowner or service technician are:

* Clean or replace filters regularly (every 2 to 6 months, depending on operating time and amount of dust in the environment).

* Clean outdoor coils, as often as necessary (when dirt is visible on the outside of the coil).

* Remove plant life and debris from around the outdoor unit.

* Clean evaporator coil and condensate pan every 2 to 4 years.

* Clean the blower fan blades.

* Clean supply and return registers and straighten their fins.

Cleaning can be done on outside units with a garden hose.

Other appliances around the home needing to be checked, cleaned or replaced are: furnace filters, refrigerator and freezer coils, exhaust fans, dishwasher filters, dehumidifiers, etc. Also, don’t forget to check and clean the filter on the lawn mover. Taking time to check these items will increase the life of the equipment and save money on energy and maintenance bills.


Ask Lorene

(This resource was added July 2008 and appeared in the Lincoln Journal Star Newspaper Sunday edition. For information on reproducing this article or using any photographs or graphics, read the Terms of Use statement)

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University of Nebraska-Lincoln in Lancaster County
Web site: lancaster.unl.edu
444 Cherrycreek Road, Suite A, Lincoln, NE 68528 | 402-441-7180