Should You Cover Your AC Unit This Winter?
HVAC experts explain why full covers often cause more damage than they prevent.
1The Hidden Risks of Covering
Many homeowners mistakenly believe that covering an outdoor AC unit with vinyl or plastic protects it from winter weather. However, manufacturers like Lennox warn that these covers trap moisture inside, which leads to rust, corrosion, and damaged electronic components. This trapped environment also restricts necessary airflow, potentially inviting mold and mildew growth.
2Pest Attraction and Warranty Issues
Beyond moisture damage, fully covering an AC unit creates a warm, sheltered environment that attracts rodents and other small animals seeking to escape the cold. These pests often leave behind debris and droppings that damage internal wiring. Additionally, some manufacturers may void your equipment warranty if you use an unauthorized full cover.
3Heat Pump Specific Guidance
If your outdoor unit is a heat pump that provides heating throughout the winter, it should never be covered. These systems are designed to operate year-round and require constant airflow to function correctly. If you are uncertain about your specific unit type, check the equipment label or consult your owner's manual immediately.
4Clearing Debris for Efficiency
The Department of Energy recommends clearing leaves and debris from the fan, compressor, and condenser of your split system before the first freeze. If you are uncomfortable reaching inside the unit to remove these items, it is safer to hire a professional technician to perform the cleaning and ensure no damage occurs.
5Maintaining Proper Spatial Clearance
Trane suggests keeping all plants, weeds, and shrubs at least two feet away from your outdoor unit to maintain optimal performance. Furthermore, their landscaping guidelines recommend trimming nearby trees to maintain a five-foot clearance above the unit. This prevents falling branches or heavy debris from damaging the system during winter storms.
6Top-Only Protection Alternatives
If your unit is located directly under trees or in an area prone to falling debris, Lennox suggests using a plywood cover or a manufacturer-approved guard. These should only protect the top of the unit, leaving the sides completely open to ensure that air can circulate freely and moisture does not accumulate.
7Managing Snow and Maintenance
Trane advises keeping heavy snow away from the sides of heat pumps and clearing the top once it is safe to do so. HVAC.com recommends shoveling at least 18 inches around the unit. Additionally, ensure you change your air filters every 30 to 90 days depending on whether you have household pets.
8When to Call Professionals
Schedule a professional maintenance check-up for your furnace or heat pump between late September and early November. If your unit remains buried in ice after a storm or fails to clear frost in defrost mode, contact a technician rather than attempting to chip away the ice yourself, which could damage the coils.
Original article: Trendir — Should You Cover Your AC Unit This Winter?