Your exterior unit is exposed to a lot of harsh weathering conditions. Regular service visits can minimize issues caused by this exposure.

1. Debris Damage

The exterior unit is fully exposed to the elements, as well as any type of debris that blows in. If there are large trees or shrubs nearby, then falling debris can lead to major damage to an AC unit. Dents, cracked unit housing, and bent condenser fins all affect the operation of the unit. An HVAC service can remove debris and fix any damage. They may also recommend placing an awning over the unit for protection.

2. Corrosion

Corrosion occurs when moisture becomes trapped in the exterior unit, usually during winter when the AC isn't in operation. The most common culprit is an AC cover. Although designed to protect an AC from damage, the wrong cover can trap moisture inside the unit and cause corrosion and rust. Covers should be open on the sides to allow air circulation. If corrosion does form, a tech must clean out the unit and replace any damaged components.

3. Flooding

Flooding can be a result of poor drainage near the exterior unit. It may also occur if the unit isn't properly elevated on a foundation pad. You can prevent flooding by installing the pad on risers and ensuring that proper drainage is installed around the unit. If flooding has already occurred, an HVAC service must inspect the unit for damage to the system, including the electrical components.

4. Vibrations

Every AC unit vibrates due to the rapid movement of the fan assembly inside. Ideally, the unit should be installed upon anti-vibration pads, which absorb the movement so that there is no noise or discernible shaking from the AC unit. If the pads are missing, worn out, or the AC has shifted off of them, you must have the unit serviced. Otherwise, the vibrations may lead to damage inside the unit. 

5. Dirt Buildup

It's a simple fact that dirt buildup inside the AC unit will occur since the unit is exposed to the outside elements. Although you can't prevent this completely, you can make sure the unit is kept clean so the dirt doesn't affect the operation or cooling ability. A technician will fully clean out the interior and the exterior of the outside unit. This means removing leaves and debris that collect inside, as well as scrubbing the condenser fins and housing. 

Contact an HVAC service if you suspect any of these problems are affecting the operation of your exterior AC unit. An HVAC service can provide further information.