To Cover or Not to Cover Your AC Unit? The Answer May Surprise You!
As a homeowner, you know there's no shortage of seasonal maintenance tasks. One question we hear every fall is:
"Should I cover my AC unit during the winter?"
It seems like a smart way to protect your investment, but the answer isn't as simple as buying an AC cover from the hardware store.
At Oasis Lawn & Pest, we look at things a little differently because we don't just think about protecting your equipment—we also think about protecting your home from unwanted pests.
First Things First: What Type of HVAC System Do You Have?
Before you even think about covering your outdoor unit, determine what type of system you have.
Heat Pump (Heating & Cooling)
Many homeowners throughout the Pacific Northwest now have heat pumps, which provide both heating and air conditioning.
These units should never be covered.
A heat pump operates year-round and requires unrestricted airflow to function safely and efficiently. Covering the unit can reduce airflow, damage the system, and potentially create safety hazards.
If you live in an area with severe winter weather, a better option is to build a properly designed shelter that protects the unit from falling ice or heavy snow while still allowing plenty of airflow. There are many simple DIY plans available online.
What About Air Conditioning-Only Units?
If your outdoor unit is used only for air conditioning, you still don't need a full cover.
Some homeowners build protective shelters that shield the unit from direct sun, wind, and harsh weather. While these can help extend the life of the equipment, they also require regular maintenance and can become expensive over time.
A Simple Alternative
If you're concerned about falling icicles or heavy snow, consider placing a piece of stained plywood over the top of the unit only. This can help protect the fan from falling debris while leaving the sides completely open for ventilation.
Just remember to remove and store the plywood before cooling season begins.
Why We Recommend Never Using a Full AC Cover
Believe it or not, I used to cover my own AC unit.
In fact, I still have a really nice cover sitting in my garage. I thought about donating it—but then I realized I'd probably be helping someone create the perfect home for mice and insects!
As pest control professionals, my wife and I spend every day helping homeowners prevent infestations. One thing we've learned is that AC covers create excellent hiding places for pests.
AC Covers Create Pest Hotels
When you place a cover over your outdoor unit, you're creating a sheltered space that's protected from:
- Rain
- Snow
- Wind
- Cold temperatures
To us, it looks like an AC cover.
To pests, it looks like luxury housing.
Spiders, ants, earwigs, and especially mice love these protected spaces. Mice can build nests inside the unit, chew wiring and insulation, and cause expensive damage long before anyone notices.
A simple cover can quickly become an invitation for unwanted guests.
Covers Can Also Trap Moisture
Another problem with full covers is moisture.
Many homeowners use vinyl covers, tarps, or even bungee cords to secure them. Unfortunately, these materials can trap moisture inside the unit, reducing airflow and creating conditions that encourage rust, corrosion, and mildew.
Instead of protecting your investment, the cover may actually shorten its lifespan.
Pest Control Becomes More Difficult
There's another issue many homeowners don't consider.
When the unit is covered, pest control professionals can't properly inspect or treat around the base of the equipment. That means insects and rodents have one more protected area around your home where they can live undisturbed.
Keeping the area accessible helps us keep your property better protected throughout the year.
The Best Winter Maintenance for Your AC Unit
Instead of covering your unit, spend a few minutes keeping it clean.
Throughout the fall and winter, periodically remove:
- Leaves
- Pine needles
- Grass clippings
- Bird nests
- Branches
- Other debris
Keeping the area clean allows proper airflow, discourages pests, and helps your system operate efficiently when warm weather returns.
Don't Forget Spring Maintenance
A little maintenance each spring goes a long way.
Cleaning your outdoor AC unit can improve efficiency and help extend its life. Many homeowners are comfortable doing this themselves with a few basic tools, while others prefer hiring an HVAC professional.
Fortunately, we're lucky to have several outstanding heating and cooling companies throughout our area that can help keep your system running its best.
The Bottom Line
Despite what many people believe, a full AC cover usually causes more problems than it prevents.
Instead of protecting your investment, it can:
- Create the perfect home for mice and insects.
- Trap moisture that leads to rust and corrosion.
- Make pest control more difficult.
- Restrict airflow on heat pump systems.
- Hide developing problems until they become costly repairs.
If you're worried about winter weather, protect the top of the unit from falling debris or build a properly ventilated shelter—but skip the full cover.
Your HVAC system—and your pest control professional—will thank you.
Need Help Keeping Pests Away?
At Oasis Lawn & Pest, we're always happy to share practical tips that help homeowners protect their homes. Whether you're dealing with ants, spiders, rodents, or other unwanted guests, our goal is to keep your home the beautiful oasis it was meant to be.
Have questions about pest prevention around your home? Give us a call—we're here to help!