While covering your central air conditioner may keep it looking a little better in the long run, an A/C cover can create a perfect habitat for critters, such as mice. These freeloaders like to use your covered-up air conditioner as luxury living space to get out of the harsh winter conditions, and may make Swiss cheese out of the wiring and other components in the unit.
Every spring, we arrive at several service calls for air conditioners not working to find exactly that. This can lead to expensive repairs that might not have happened if the unit was left uncovered.
On the other hand, we also have had to replace the top portion of the air conditioner due to ice and other debris falling on them from the roof, which may have been protected if covered.
So what do we recommend?
The answer varies depending on a few conditions, like where you live. If you live in Florida, where your air could be running a good portion of the year, then it really doesn’t make sense to cover it.
But here in Oklahoma, where the temperatures can fall below zero degrees and ice storms can pile up precipitation on units, it may be worth considering some sort of shelter.
In our opinion, it's best to leave the A/C unit uncovered. In the spring, our company handles more repairs for units that were covered during the winter. However, if you have ice that often forms on the roof above your air conditioner, then I recommend putting a piece of plywood over the top of it to reduce the possibility of damage from falling ice.