Yesterday, we featured 5 Tips for Annual Air Conditioner Maintenance. It was a helpful article for anyone with central A/C, but Unplggd reader Amanda H pointed out that we completely neglected many small, cool dwellers with window or free-standing air conditioning units.
Just like any other appliance in your place, the window A/C also needs tender love and care. Make sure to give it a thorough cleaning at least once a year:
1. Wash the filter.
The main thing to do to upkeep your window unit is to make sure you wash the filter screen on a regular basis. After popping out the front grill of the unit with a putty knife, remove the mesh filter. Wash it together with the grill in a mixture of warm, soapy water and bleach to remove any mold.
2. Clean the coils.
You'll find evaporator coils underneath the filter. To keep your A/C going strong, you'll want to vacuum them thoroughly using a brush attachment. Remove any stubborn dirt with a plastic scrub brush. Do the same thing with the condenser coils at the back of the A/C unit. The idea is that extra debris gets in the way of air flow—an your cool air.
3. Straighten fins.
Use a fin comb to straighten any bent coil fins. You can find fin combs at a home or hardware store or online for around $10.
(Image: Flickr user skeddy in NYC under license from Creative Commons.)
100 DIY Ideas for the 3-Day Weekend
Danielle's Charming, Classic Walk-Up
Good Food to Share 
The Big Book of Small, Cool Spaces 
Apartment Therapy Presents 
The Eight-Step Home Cure 
White Enamel Flatwa...
Party Recipe: Creamy Crawfish Dip
Perfect Summer Cocktail Recipe: Honey Bourbon Lemonade
Thanks so much! I know what I'll be doing this weekend! :)
i have a few tips of my own:
1. there's a foam spray for the evaporator fins you can pick up at places like home depot called 'foam coil cleaner'. the one i use is from ac safe. you can google it or search home depot.com for foam coil cleaner.
it's self-cleaning -the foam dissolves into liquid and evaporates or drips out via the condensation pan, leaving no mess. it leaves a bit of a mild lemon scent that fades away. on regular ac use i would use it once a month.
2. another tip is to avoid adding any extra filters such as hepa or charcoal. it may actually damage the air conditioner because the intake air flow is hindered from how it is normally designed. this can lead to repair issues or lower the cooling potential of your unit.
3. if you're not afraid of opening up the window unit, clean the fan blower with a damp cloth. blockage can reduce air flow and possibly result in wear and damage. if it has oil ports, apply a few drops as well.
4. lastly, during winter months of non-use it's a good idea to either:
a. cover up the rear of the unit, or
b. remove the unit from the window and place in storage.
to protect it from dust and elemental corrosion. you wouldn't want the first time of the season to be blowing dust and pollen into your living space.