As colder weather approaches, many homeowners begin to think about protecting their outdoor air conditioning units from the elements. A common practice has been to cover the AC unit in winter to shield it from snow, ice, and debris. However, this well-meaning action can cause more harm than good. In fact, it’s best to leave your air conditioner uncovered throughout the winter. Here’s why, along with tips for proper winter maintenance of your AC unit.
1. Moisture Trapping Leads to Damage
Covering your AC unit can trap moisture inside, which can create the perfect environment for mold and mildew growth. When moisture gets trapped under a cover, it doesn’t have the chance to evaporate naturally. This excessive moisture can lead to the corrosion of essential components, such as coils and wiring, reducing your unit’s lifespan.
A 2021 study by the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) found that moisture-related damage accounts for nearly 30% of repairs in outdoor AC units, often due to corrosion or rusting of key parts.
2. Pests Seek Shelter
An air conditioning unit cover can become an inviting shelter for small animals like rodents, birds, and insects during the colder months. These pests may find refuge inside the cover and cause significant damage by chewing wires, nesting in parts of the system, or blocking airflow when spring arrives. Rodent damage alone accounts for a significant portion of costly repairs, with the average cost of repairs related to pest damage hovering around $500 to $1,500, depending on the extent.
3. Modern Units are Designed for the Elements
Most modern AC units are built to withstand harsh outdoor conditions without any need for covers. They are made from weather-resistant materials and have proper ventilation to handle rain, snow, and ice without suffering significant damage. The coils are designed to drain moisture effectively, and the housing is durable enough to prevent debris from causing harm.
In fact, using a cover can interfere with these built-in protections, trapping moisture or blocking airflow, which are critical to the unit’s longevity.
4. Risk of Condensation
Even during winter, fluctuations in temperature can cause condensation to form inside a covered unit. The constant freeze-and-thaw cycle can damage coils and other internal components. Over time, this can lead to unnecessary wear and tear, potentially causing premature failure of the unit.
Winter Maintenance Tips for Your AC Unit
While you shouldn’t cover the AC unit in winter, there are still important maintenance tasks you should perform to ensure your air conditioner is in good shape when warmer weather returns.
- Clean Debris Around the Unit
Before winter sets in, make sure the area around your AC unit is free from leaves, twigs, and other debris that could accumulate and restrict airflow. Clear at least 2 feet of space around the unit to ensure proper ventilation. - Inspect for Damage
Take a moment to inspect the exterior of the unit for any signs of damage. Look for bent fins, loose parts, or cracks in the housing. Addressing these issues now can prevent further problems later. - Cover Only the Top of the Unit (If Necessary)
If you’re concerned about falling debris, place a cover on the top of the unit only, leaving the sides open. This allows for adequate airflow while still preventing leaves or snow from building up directly on top of the unit. - Turn Off Power to the Unit
Make sure to shut off the power to your air conditioner during the winter. This prevents it from turning on during an unseasonably warm day, which could damage the system due to freezing temperatures. Most units have a disconnect switch near the unit itself. - Check the Unit in the Spring
When spring arrives, do a quick inspection of your air conditioner before turning it on for the season. Clean any debris, check for signs of damage, and ensure that the area is still clear for optimal performance.
The Takeaway
Although it may seem like a good idea, you should not cover the AC unit in winter as it can cause more harm than good by trapping moisture, inviting pests, and interfering with the unit’s natural ability to withstand the elements. Instead, focus on keeping the area around the unit clean and following proper winter maintenance steps to ensure your AC is ready for the next cooling season. By avoiding the cover and following these simple tips, you’ll extend the life of your system and avoid unnecessary repairs when the temperatures rise again.