As the scorching summer heat starts to fade and the cooler temperatures of fall starts to settle in, residents of The Bay Area start preparing their homes and yards for the winter. For many, that leads to the question of whether they need to cover their outside air conditioning unit for the winter.

While it may seem like a good idea, the reality is there are multiple reasons why you shouldn’t cover your AC unit in the winter. Along with not being needed, covering your outdoor air conditioning equipment can actually cause problems.

Here, the professionals at Contra Costa Heating & AC share five reasons why covering your air conditioning equipment doesn’t need to be on your fall to-do list and what you should do instead.

1. Your AC Unit Isn’t Damaged by Snow

Exterior AC units are built to withstand harsh weather conditions like snow in the winter. These machines are built with sturdy materials and hardware that can handle the outdoor elements without damage. The coils and fins of the unit are constructed to resist corrosion, and the housing is designed to protect the internal elements from moisture and debris.

2. Covering AC Systems can Encourage Mold

One of the reasons you shouldn’t cover your AC unit in the cold months is because doing so can trap moisture—which is not at all what you want in your outdoor unit. That’s because sealing moisture inside the unit generates the perfect conditions for mold and mildew to flourish.

Mold and mildew not only have a bad aroma, but they can also pose health risks, especially for household residents with respiratory issues or allergies. Also, the unwanted moisture can corrode the internal components of the AC unit.

Rather than covering the unit, instead ensure proper drainage and keep the area around the unit cleared of debris, allowing for efficient airflow and preventing moisture buildup.

3. Covered AC Systems Can Attract Animals

People aren’t the only ones who prepare for winter. Animals that live around your home are also searching for a warm, cozy place to crash for the cold months. For many creatures, a covered air conditioner is the perfect winter refuge.

Birds, mice, chipmunks and even rats often make nests inside covered air conditioners. Animals residing in a covered air conditioner can cause many problems. Mice can chew through wires, insulation and other connections, causing damage that may require costly repairs. Debris animals bring into the AC to create a warm and comfortable bed can block airflow and ventilation, lowering the efficiency of the unit and potentially causing it to overheat. Moreover, animal waste can result in unsanitary conditions and bad odors.

Leaving your air conditioner uncovered helps deter creatures, because an uncovered AC offers less shelter from cold weather than a covered unit. That’s better for your air conditioner—and leaves you with less mess to clean up and things to repair in the spring.

4. Covering Your Air Conditioner Restricts Airflow

Another reason not to cover your air conditioning equipment in the winter is because a cover blocks airflow through the unit. Adequate airflow is vital for the AC system because it assists heat exchange and allows the unit to cool effectively. When airflow is constrained, the system has to work harder to reach the desired temperature, resulting in additional energy consumption and strain on the components.

In addition, if you use your AC without noticing that the outside unit is covered or because you simply forgot, it could result in a range of problems. One issue is that the lack of correct airflow could cause the compressor to overheat, resulting in its failure or damage.  That’s why it is vital to ensure the outdoor unit is free from barriers and is not covered to maintain optimal airflow.

5. AC Maintenance Offers More Benefits Than Covering Your Air Conditioner

The bottom line is, it’s much more effective to do a little maintenance for your air conditioning unit than to cover your outside AC unit.

There are a number of key maintenance activities you should prioritize to ensure the best possible function and longevity of your AC unit. First, it’s a good idea to inspect your outdoor AC unit regularly and pull out any debris such as leaves, small branches and dirt to maintain proper airflow. Second, check and clean the coils, fins and filters to make sure you don’t see any dirt and dust buildup that would impede efficient heat exchange or airflow.

Regular air conditioning maintenance not only enhances efficiency, but it also helps extend the unit’s life span, decreases energy consumption and avoids costly repairs. Rather than using a cover, putting time and effort into routine air conditioning maintenance is a proactive strategy that can significantly benefit your entire HVAC system in the long run.