Why Covering Your Air Conditioner May Not be Necessary.

When summer comes to an end and temperatures start to drop, we naturally transition from air conditioning to heat to stay comfortable, leaving our AC units inactive until spring. Many homeowners wonder if they should cover their air conditioner during harsh winter weather. It only makes sense to protect it from the ice and snow as we do with other summer appliances, right? 

Well, that conclusion isn’t as obvious as it sounds.  

Covering your AC unit completely, especially with a plastic or vinyl material, can actually do more harm than good. We’re not saying every air conditioner should go unprotected, only that there are a few things to consider before you decide whether you should cover yours – and if you do, how to go about it.   

Does Your AC Unit Need a Cover in Winter? 

The short answer is no. Modern Air Conditioners are designed to live and operate outdoors and typically don’t require winterization. The finishes, structural components and electronics today’s manufacturers use are built to tolerate harsh conditions – hot and cold – and continue operating year after year. However, there are situations where adding the right type of protection can be beneficial.  

While we don’t advise completely covering your air conditioner, especially with any non-breathable material, there are instances where specific types of protection are beneficial. 

Generally, this decision is based on your location and the types of hazards that your equipment is likely to face during the winter. Let’s look at the positives and negatives of covering your unit and explore a few proper ways to protect vulnerable equipment.

Potential Issues with Using Covers 

Covering an air conditioner is generally not recommended by experts and manufacturers, especially with plastic, vinyl, or any other air-flow-restricting material. Air conditioners are designed to operate in open air, restricting that air flow can allow moisture to accumulate, leading to problems come springtime – or further down the road. For most homeowners, there are many reasons NOT to cover your air conditioner. 

• Moisture captured under a cover can lead to rust and corrosion, damaging your AC’s components and finish 

• The humidity that comes along with that moisture can damage electronic components 

• Lack of airflow can invite mold and mildew 

• Covered AC units can attract rodents and other small animals trying to escape the cold 

• Accumulated moisture can result in temperatures under the cover that are lower than the outside air – and possibly freeze your unit’s coils 

• Depending on your manufacturer, covering your unit may void its warranty  
  

When Might You Consider Covering Your AC Unit? 

Though it’s generally not recommended, there are situations where adding protection to your air conditioner is helpful. You may want to consider adding some type of cover to your unit if:

• Your air conditioner is in an area where it could be damaged by falling debris or accumulate falling leaves from nearby trees.  

• Your HVAC technician advises you to do so based on your location or coming weather. 
  

Even in these conditions, restricting airflow should still be avoided. There are several ways to protect your air conditioner without preventing proper ventilation: 

• Secure a covering such as plywood to the top of your air conditioner to prevent falling debris and reduce ice build-up on the internal components. 

• Build a shade or extend the awning over your air conditioner to reduce exposure. Be sure not to restrict the airflow above the unit.  

• Use a lightweight, breathable cover than won’t accumulate water or restrict airflow. 

• Hire an HVAC professional to perform a winter inspection to clean it, and address any issues.   
  

Some manufacturers also offer custom-fitted plastic protectors that secure to the top of their equipment to deflect debris and prevent ice and snow build-up. You can check with your manufacturer or ask your HVAC technician if one is available for your air conditioner. 

If you do decide to cover your air conditioner, be sure to inspect, clean, and remove any existing debris from inside the unit before applying your cover.

The Final Verdict? 

Though there may be certain instances where adding a cover or protection to your air conditioner during the winter is prudent, the possible negative effects usually outweigh the benefits. But because all outdoor air conditioners are durable and were designed to “weather the weather”, we don’t recommend it unless you have a compelling reason.

As an alternative, we do recommend other ways to protect your HVAC investment:

• Schedule regular professional HVAC maintenance. 

• Clean and inspect your air conditioner regularly. 

• Check and replace your filters according to the recommended schedule.

We hope this little guide to protecting your air conditioner in winter helps you get the most from your HVAC system for many years to come. If you’d like any additional information about air conditioner or HVAC system maintenance, reach out to your local Lennox pro to schedule a visit. 

This has been reviewed by Nick Orth, Director of Outdoor Cooling, for accuracy. Nick brings over 20 years of expertise in the HVAC space.