As we have mentioned, air conditioning season has begun, which is the perfect opportunity to give your machine a good clean. Ensuring that the outdoor unit is clean will increase the lifespan of the machine, as well as make it more energy-efficient. Here’s how to do it:
1. Turn it off! The power switch should be in a small box near the machine.
2. Clear the area. Remove any leaves, branches or debris that may be stuck in the condenser fins (the thin metal pieces that run along the exterior of the unit). Vacuum the fins with a soft-bristle brush attachment, making sure not to bend any of the fins.
3. Unscrew and remove the top grille – the fan will most likely be attached. Vacuum any debris around the motor.
4. Wash it all away. Using a hose with direct spray, wash down the interior walls, avoiding electrical components and without bending any fins.
5. Wipe fan blades with a damp cloth, and screw the grille back on.
6. Enjoy the cool air and a job well done!
Courtesy of The Huffington Post
http://www.huffingtonpost.com/2012/05/31/how-to-clean-outdoor-air-conditioner_n_1556798.html