Should I Cover My Outdoor Unit During Colder Months?

Your Air Conditioner Was Built to Withstand Harsh Weather

Your AC’s evaporator coil and blower are located inside your house while the compressor and condenser are located outside. Although the condenser and compressor are important parts of your unit, they were designed to withstand the harshest weather conditions. When a manufacturer creates something that is going to be exposed to the elements for as long as it exists, the company has to put in place measures to protect the unit from inclement weather. For instance, your outdoor unit’s electrical components are sealed to keep out moisture. If you examine it closely, you will see corrosion-proof materials, such as aluminum, copper and plastic that keep your unit’s internal components from rusting.

Covering Your Unit Can Invite Pests

When the weather becomes extremely harsh, rodents and other small animals start looking for shelter to protect themselves. When you cover your air conditioner, you create the perfect hideout for them. When they inhabit the unit, they may start nibbling on things like the wires and uninsulated refrigerant lines. In addition to the electrical problems this damage can cause in the unit, punctured lines may let out the refrigerant and make your unit less efficient.

Covering Your Unit Can Invite Mold and Mildew

Mold and mildew love moisture. When you cover your unit, you trap moisture inside the unit and encourage it to grow fast on the evaporator coils. Your outdoor unit was made to be open to outdoor air and stay free from fungi. Although mold may not damage your health directly when it grows inside your outdoor unit, it can prevent air from flowing properly through the coils, thus lowering the efficiency of your unit.

Moisture Will Still Infiltrate Your Outdoor Unit Even When Covered

The main reason why people cover their outdoor units is to keep water from getting in and damaging the internal components. However, during the cold season, the air is usually humid. The moisture can enter the unit naturally with or without the strong winds that are usually present during winter. Similarly, moisture can find its way into the unit from the ground as it evaporates. When the unit is open, air can flow and help the water to evaporate on sunny days. When the unit is covered, the moisture is trapped inside; it condenses into water over time, leading to small pools of water on the floor of the unit. This water may freeze on the condenser coils and damage them.

How About the Debris?

Another reason why people cover their outdoor AC units is to prevent the accumulation of debris inside the unit. They also do it to prevent leaves and branches from falling on the unit and damaging it in the fall and winter. However, these are issues you can control in other ways. If there is a tree near your outdoor unit, you can prune the branches to prevent them from falling unexpectedly and damaging the unit. As a part of a scheduled tune-up, a professional will clean your outdoor unit to remove any debris before it becomes problematic.