Is it necessary to cover an air conditioner in winter?

It is important to look after air conditioners in the correct way in order to make sure that they will last a lifetime. Varying temperatures through different seasons can have an effect on the AC systems, and often when it comes to winter, people are not so sure of the best way to look after them. This is due to the cold temperatures, snow, ice, and any dirt and debris brought by storms which may worry a lot of people who keep their compressors outside.

However, it is true that most air conditioners’ outside compressors and condensers are usually able to withstand harsh temperatures due to their protective and high quality design, and they are typically crafted to handle the elements quite well.

Covering your air conditioner during the winter months must be done in a certain way as this can actually bring about more problems than it is worth! We will share why that is the case in this article. Therefore, if you are still pondering if it is necessary to cover your air conditioner altogether throughout the Winter months, then check out the following reasons why it is actually not necessary to cover it.

Rodents can Infest covered Air Conditioners

One of the worst things that can happen concerning your air conditioner throughout winter is the arrival of rodents, who come to find shelter from harsh conditions. Unfortunately, this is pretty common with covered air conditioners during long winter months.

By covering it, you are providing a shelter which is warm, humid, and still dry enough to offer optimum hibernation conditions for small rats and mice. This can, of course, lead to further issues such as chewed wires and uninsulated Freon lines due to rodents using them for nesting materials.

Mold and mildew can grow within the unit

Air conditioners are made to be open to the fresh air. Therefore, covering them up creates an environment that the air conditioner is not built to deal with, and that is an environment which includes mold. By covering the air conditioner, you will block proper air flow which leads to mold growth on the evaporator coils. This will further lead to a lack of performance on the inside of the building, and hence decrease the air conditioner’s overall efficiency.

Moisture can infiltrate your AC unit

One of the main reasons you should not cover your air conditioner in the winter is down to water. Moisture will get into it by accumulating from the humidity which is naturally in the air, and also from wind blowing inwards. Evaporating water from the ground can also get into the system, and therefore there is no escape. Many people think that covering the air conditioner will help prevent this; however, it is pretty tricky to keep moisture out.

Can I cover my air conditioner in winter?

Yes, there is absolutely no problem with covering your air conditioner if you wish. However, with that being said, after reading all of the reasons why it is not necessary to do so and to avoid any of those consequences, make sure to only cover the top of the air conditioner.

You want to make sure to only cover the top and not the whole unit, as covering the entire unit would trap moisture and cause the system to possibly rust and corrode. Vinyl covers that wrap around air conditioners are especially not recommended as they trap air and cause corrosion after long periods.

Another risk of covering the air conditioner is if someone accidentally bumps into the thermostat and turns on the unit by mistake. This will burn up the air compressor and remove several years off the life of the system. Therefore, it is recommended to leave the cover off the air conditioner altogether and clean it in the spring using a hose following the proper safety precautions, or even have a professional technician come out and maintain it.

Are there any times I should definitely cover my air conditioner?

As we have mentioned the reasons why it is not necessary to cover it during winter, it would be useful to know instead when it is necessary to cover your AC unit.

During Hail Storms

As you can probably imagine, a hail storm would likely do a lot more damage in the space of a few minutes than a few months of cold temperatures. Strong hail storms in particular have the potential to knock the whole system out. Therefore, in this case it is wise to cover the air conditioner before the storm arrives. Because hail can be hard to predict, perhaps cover it in any case storm in order to be safe!

During Blizzards

If a blizzard is heading your way, then it would also be a wise decision to cover the air conditioner. Why? If any snow gets into the AC, freezes, and later melts, it will damage the coils. Therefore, it is best to cover the unit before a blizzard starts in order to prevent this from happening.

How to cover it correctly

If you still would prefer to cover your air conditioner, then here are a couple of suggestions you can follow to make sure you do it the right way, preventing moisture and keeping the unit fully protected.

  • Use a cover over the top which is made of breathable material
  • Put a piece of plywood over the top of the unit to protect it from any snow and ice, and weigh it down with heavy stones or bricks to secure it in place
  • Plant some small shrubs around the AC to protect from wind and blowing snow
  • Build a small shelter for the air conditioner that provides good protection in the winter and shade during summer. It is easy to find some tips and designs online via sites like Pinterest.


So there you have it, some reasons why covering your air conditioner in winter isn’t so necessary after all, as well as some instances in which it is absolutely necessary. Air conditioners are usually a very expensive investment for most.

As such, it is wise to know how to look after it the right way, in order to make it last for a good few years! Hopefully, this article has given you some advice when it comes to looking after your own air conditioner and some pointers to keep in mind for next winter!

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