Outdoor AC units: Will a cover help or hurt your systems?

Outdoor AC units are built to withstand harsh elements, so covering them isn’t necessary. Although most manufacturers recommend against covering them, each homeowner should make an informed decision.

Why are outdoor AC covers sold?

Despite an outdoor unit’s external cabinet being reinforced with durable materials, such as galvanized steel, baked-on powder coatings, and rust-inhibiting paint (and the electrical connections and coils being sealed and protected), some homeowners choose to cover their units based on individual needs and preferences.

Understanding the main pros and cons of using a cover can help you make the best decision for your system–and help you avoid the pitfalls if you do decide to cover up. 

Advantages of using a cover for your outdoor AC

Depending on your surroundings, and if used correctly, a cover can offer added benefits such as:

• In autumn, a mesh cover can prevent debris like sticks, acorns, pine needles, and leaves from clogging the condenser while still allowing airflow. 

• In particularly cold climates, a hard cover can protect AC components from snow and ice in the winter months.
• In spring, a breathable cover helps minimize dirt, pollen, and dust, increasing unit efficiency. 

Disadvantages of using a cover for your outdoor AC

Most major brands state their outdoor AC units are engineered to withstand rain and moisture, UV sunlight, temperature swings, and moderate snow/ice, so if you decide to cover up, remember that improper cover use can compromise the unit’s built-in defenses. 

Here are the main disadvantages of using a cover:

• Forgetting to remove the cover before turning on the unit can restrict airflow, causing it to overheat, trip-out, or incur compressor damage. Many people have their AC units on automatic timers, which makes forgetting to take off the cover even more common. 
• Non-breathable covers can trap moisture inside, leading to rust and corrosion of unit parts.
• Reduced airflow beneath a cover creates an ideal environment for mold, mildew, and bacterial growth within the cabinet.
• A covered unit provides the perfect home for small animals, which can expose the unit to various debris that can cause damage.

There’s one exception you should know: if your home has a heat pump in addition to an AC system, you should never cover the outdoor unit because it’s a fire hazard. Since heat pumps operate year-round, covering the unit could cause overheating, posing a fire hazard.

Don’t have an outdoor AC yet, but are considering one? Check our selection of energy-efficient home AC systems.