While there are a lot of air conditioning maintenance tips you should follow, different measures should be taken for window mounted air conditioning units. These units are unique in that they sit outside the window, cool one specific area, and are generally removed seasonally. Follow these tips to keep your window AC unit functioning efficiently and effectively:

Clean or Replace Air Filter

Generally, air filters should be replaced every 1 to 3 months. If the air filter is permanent and can’t be replaced, it is easy to clean. Remove the filter, brush away any bigger debris, build up, or dust, gently wash it with a warm water, dish soap, and white vinegar. Make sure to let the filter dry completely before reinserting it. If you have allergies or pets in your home, consider replacing or cleaning air filters more often.

Inspect and Clean Coils

The coils on the outside of the unit naturally get dirty from the outdoor elements. Blow compressed air or use a soft bristle brush and a spray bottle of household clean to wipe off dirt. If the coils become tangled, use a fin comb to straightened them back out.

Clean the Water Pan

It’s necessary to clean the water plan in order to prevent mold and mildew growth. These growths can produce a musty odor in the air. Use warm water, dish soap or white vinegar to clean the inside base of the unit once it is taken apart.

Fill in Extra Spaces:

If there is space between the accordion sliders and the window or perhaps small cracks of air underneath or above the unit, it can waste a lot of energy. There are a few different solutions to this problem that vary depending on if the unit is permanently left in the window or removed seasonally:


Use caulk to seal empty spaces around the unit and reduce the chance of leaks. For best results, caulk during dry cool weather. This increases the likelihood of the caulk sealing correctly. For more extreme measures, use spray foam to fill in cracks. Spray foam is very effective, but should only be used for permanent units as it is very difficult to remove.


For units that are removed seasonally, plumbers putty, foam, and weather seals are all great options. Plumbers putty is a clay like substance that is typically used during the installation or repair of drainpipes and sinks. However, because of it’s pliable nature, it can be a good solution to fill in gaps around the window. It may leave a sticky residue behind, but should be able to be cleaned up. Foam insulation can be placed gently around the unit and can also prevent any prevents any rattling or vibration coming from unit. Weather seals act similar to the plumbers putty and are easy to place around the unit.

Store Properly

When it’s not AC season, it’s important to store your unit properly. If it is a permanent unit, use a protective covering to repeal the harsh elements of cold months. If it is a removable unit, clean it before storing it. It’s best to remove it from the window if possible to not only protect the unit, but also to seal in warm air inside your house during the cold months by having the window completely closed.

If you’re frustrated with window AC units and are considering other options, contact Blue Ox Heating and Air. Our technicians will walk you through your options and help you find the best solution for your home. Ductless air conditionersare a great alternative to window units for homes without ducts. Contact Blue Ox or schedule your service online, today!

Comments are closed.