It is very important to keep the area around your air conditioner clean and free of clutter. If you have large boxes, and other materials around your AC unit they could reduce its ability to suck in air. It is also very important that you cover your unit during the winter months so the fans don't get rusty. If your fan blades are rusty, or have calcium build up, they will not be as efficient as they should be. This article explains how to change the fan blades on a residential air conditioner, should they get rusty or sustain other damage.
Getting a Replacement Blade
An AC fan blade is not something that you can just pick up at a home improvement store. You will need to order it and have it delivered to your home. To ensure that your new blade fits perfectly, you should order a replacement directly from the manufacturer. You are more likely to have problems with bolt threading if you buy the blade from a third party manufacturer. You will pay more for a manufacturer's blade, but it is well worth having the extra quality.
Accessing the Fan Blades
The first step is to cut the power to the AC unit. Air conditioners do not have traditional plugs, so you will have to find the breaker and switch it off. Next, you will have to remove the protective cage at the top of the unit. Depending on your particular brand, the cage will either be attached with screws or bolts. So, if you have a basic phillips head or adjustable wrench, you should be able to remove it. Once the cage is removed, you will need to remove the large bolt at the top of the fan. This nut, especially if it is rusty, can be hard to loosen. So, feel free to lubricat it. As you remove the nut, take care not to drop it or any of the washers. Pay attention to the order in which the washers are stacked, so you don't have any problems with the reinstallation.
Changing the Fan Blade
The fan blade should be easy to remove by just pulling straight up. Once again, you may need to use some lubrication if bolt is rusty. While the fan is out of the unit, you should throughly clean the empty fan compartment of the unit. Dirt and leaves often fall underneath the blade and clog the output duct.
When reattaching your new blade, you can use new bolts and washers. Just make sure that you order them when you order your blade. Hand tighten the nut as firmly as possible.
Finally, you can reattach the protective cage, and turn the power back on to test your new blade. Listen to the fan to make sure it sounds normal on the first test. Shut it off immediately if anything sounds out of whack.
If you're really struggling, consider looking into local professionals for additional info.