Should I Cover My A/C Unit In the Winter?


Autumn has arrived in Des Moines and winter is following close behind. As the leaves drop and cold temperatures creep in, many homeowners start thinking about winterizing their homes. But what about winterizing your air conditioner? How does rain, cold, dirt, and debris affect your outdoor AC unit?

A/C units were built to withstand the rain and cold of the winter. All external HVAC equipment is made to deal with harsh weather conditions and varying temperature extremes. They’re tough! As you already know, Iowa is known for harsh winter weather conditions with lots of snow, ice and harsh wind.

Rain, hail, sleet, and even snow are no match for an A/C unit. They’re more reliable than the mailman! Despite this fact, covering your outdoor A/C unit during the fall and winter months has been the subject of a debate in the industry for many years. You can read on below to explore the pros and cons of covering your A/C unit.

Cons to Covering Outdoor A/C Unit

  • Increased risk of rust: Covering an entire unit may actually trap moisture into the system by creating a high humidity environment that may cause rust and corrosion. Inside this moist environment is your electrical wiring, wiring connections, and in some cases circuit boards. None of these items do well in moisture.
  • Mold risk: Your air conditioner is made to be open to the air. Covering your air conditioner will block proper airflow which can lead to mold growth on your evaporator coils. The mold can block proper airflow through your coils and decrease your air conditioner’s efficiency.
  • Critter invasion: Rodents and other animals seek shelter from harsh winters and will often start to inhabit a covered air conditioner. They might think of it as a tiny home for mice! “Oh look, somebody made us a nice little house”. This can lead to other problems like chewed electrical wires and uninsulated freon lines due to the rodents stripping them to make a nest. Soon you could have a whole litter of mouse pups in your air conditioning unit.
  • Manufacturer recommendation: Most manufacturers do not recommend covering your A/C unit. Air conditioners that operate year-round are built to withstand an outdoor environment and don’t require coverage.

Pros to Covering Outdoor A/C Unit

  • Cleaner coils: It keeps your air conditioner coils a little cleaner so it may run a little more efficiently when you use it again.
  • Deterring debris: A cover will prevent debris like leaves, sticks, and other yard waste from blowing into your A/C unit.
  • Preventing freezing: Covers help prevent water from directly resting on your coils and freezing, which could be damaging.

Which Kind of Cover is Best for Outdoor HVAC Units?

If you insist on covering your outdoor unit there are a variety of options and covers available. Although it may look a bit janky, a compromise could be a piece of plywood across the top of your outdoor unit. It is inexpensive, will keep out most debris, and leaves the sides open to keep moisture and small creatures out.

There are also mesh air-conditioner covers available that don’t block airflow as well as a product called a Kool Kap air conditioner lid, which is designed to keep out leaves, dirt, and debris. Kool Kap is the world’s only permanent, protective air conditioning cover, which can be left on year-round and lifts automatically when your AC system is running.

If you do cover your air conditioner, make sure you only cover the top to prevent leaves and debris from falling inside the unit.

Ultimately, there is no perfect answer. Frankly, it’s really up to you, the homeowner. It’s America. You have a choice!

The best way to treat your A/C unit is to have it regularly serviced by a certified premier HVAC technician from Service Legends. We’ll do a thorough inspection of all of your central air conditioning systems. We’ll even clean out the leaves and debris that accumulate in your outdoor unit during fall and winter. Our professionals can also help you prepare for winter with furnace tune-ups, furnace repairs, and new heater installation.

HVAC Service in Des Moines

If you have any questions or concerns about your outdoor A/C unit, don’t worry, we’re on it! Give Service Legends a call or schedule an appointment online with our Central Iowa HVAC experts and we’d be happy to help you.

515-657-6634Request Appointment Online

Related Content