Your home's air conditioning system can seem complex. There's the indoor condensing coil, the outdoor unit, the ductwork, and the thermostat. Of all these components, there's one that requires a bit more care and attention than the others: the outdoor unit. Because it is exposed to wind, rain, dust, and everything else outdoors, this appliance requires some maintenance to keep it running well. If you stay on top of the maintenance, it won't be too bad. Here's how to do that:

1. Keep the weeds trimmed back.

If weeds grow into or around your air conditioning unit, a couple of problems can occur. The weeds can trap moisture against the unit, causing it to rust and corrode prematurely. The other issue is that the weeds will impede airflow, which may cause the air conditioning unit to get too cold. When this occurs, ice can form on the outside of the air conditioner, which is not good for it. Plus, your house won't get cold! 

Trim the weeds back so that there is always at least 2 feet of space on all sides of the AC unit. Be careful not to catch the AC unit with your weed whacker as you trim. (Use hand clippers, if needed, to do the work.)

2. Remove debris from the fins.

As leaves, twigs, and other little items blow through your yard, they may sometimes get caught in the air conditioner's fins. It's important to remove the cover of the AC unit and pull them out every now and then. You can do this twice a year—once in the spring and once in the fall—for good results. You may need to undo a couple of screws to lift the outer cage off the unit. If you can't grasp the twigs with your fingers, use a pair of tweezers.

3. Straighten the fins.

While you have the cover off to remove debris from the fins, you should also straighten the fins. Bent fins can reduce the airflow through the unit, leading to increased energy bills. If there are just a couple of bent fins, you can use a butter knife to straighten them. (Turn the power off to the AC unit first!) If there are a lot of bent fins, which there might be in an older air conditioner, you will want to buy an instrument known as a fin comb. You place its tines between the fins and pull downward. The fins straighten as you go.

4. Hose the unit off.

About once a year, you want to give the air conditioner a thorough bath. You don't need any shampoo or cleaner to do this unless the unit is really dirty. Just turn the power off, remove the outer cover, and hose the fins off. Let the unit dry, and then put the outer covering back on. If the unit is really dirty, you can use a dilute mixture of dish soap and water to safely clean away dirt buildup.

5. Cover the unit in the winter.

During the winter when the snow starts flying, a cover can help protect your AC unit. However, you need to use the right cover. Never bungee-cord a tarp around the unit. Although this seems like a good idea, it can trap moisture against the AC unit, doing more harm than good. Use a cover made specifically for your AC unit. It will balance moisture properly so you don't have to worry about corrosion. Make sure you remove the cover before you turn your AC back on in the spring!

With the maintenance tasks above, you will keep your outdoor AC unit in the best shape. Contact an air conditioning service company in your area for additional advice.