Key Takeaways
- Covering your outdoor AC unit during a Minnesota winter is often unnecessary because most modern units are designed to withstand cold temperatures and typical winter conditions.
- A cover can trap moisture, causing rust, mold, and damage to electrical components, so airflow is key and breathable materials should be used if covering is necessary.
- as covers can entice small animals looking for refuge — leading to nests and potentially expensive damage repairs. Routine checkups and prevention can stave off these problems.
- Manufacturers do not usually suggest covering, save in the case of protection from falling debris, so be sure to consult your unit’s manual for tips to keep your warranty valid.
- Regular winter preparation — such as cleaning around the unit and maintenance appointments — do more to protect your system than covering it.
- If you do cover your unit, select partial coverage or breathable materials and be sure to fasten the covering securely without blocking ventilation or drainage.
So, should you cover your ac unit during a Minnesota winter? Most experts say no.
Today’s external units are designed to resist snow, ice and chilly wind. Covers can trap moisture, which can cause rust or mold. Small debris such as leaves should be removed, but full covers aren’t necessary.
The bulk of this post explains and provides easy advice that keeps your AC healthy.
The Covering Conundrum
Covering an outdoor AC unit in winter is always a controversial topic. A lot of homeowners are eager to shield their investment from the elements, but the dangers and advantages aren’t always transparent. In Minnesota’s rough winters, the conundrum is does a cover help or hurt more.
1. The Case For
Covering your AC unit can make sense if your home sits under large trees or near construction sites. Branches, twigs, or dust that falls can accumulate on the unit, obstructing airflow and damaging the fins. For these types of situations, a breathable top cover might keep debris out without holding in moisture.
Others cover protect the unit from severe winds, ice, or heavy snow. A soft mesh cover, for instance, can prevent leaves and large debris from accumulating, yet still allow airflow. For others, this step can provide peace of mind, knowing they’ve done something to defend against winter’s volatility.
These advantages come with potential disadvantages, such as trapped moisture and critters.
2. The Case Against
New air conditioners are engineered to withstand the harshest of weather, from hot summers to chilly winters. Rain, snow and ice seldom damage an uncovered unit, because the components are constructed from weather-resistant materials such as aluminum and galvanized steel.
Covers can trap moisture, particularly if they wrap the unit completely, increasing the chances of rust and coil freeze. Worse, a covered, dark and dry area can lure rodents and birds seeking a warm winter abode. Nests and droppings inside the unit can result in super expensive repairs.
3. The Moisture Trap
A complete cover reduces air circulation, harboring moisture within. When water is trapped, it can’t dry out, particularly in the colder months. The consequence is mold and mildew, which may begin to develop on coils or wiring.
This moisture can eventually erode electronic components, causing them to malfunction or outright fail. Airflow is key: letting the unit “breathe” helps keep moisture from settling in. Rust, while it can begin as a minor blemish, unchecked, rust can eat through unit parts and slash the lifespan of your AC.
4. The Critter Condo
A covered AC unit can suck up small animals looking to nest. Rodents and birds — even bugs — may make the dark, safe nook ideal for nesting. Their nests may cover or block fans, or wiring.
After the pets have settled in, it’s a battleground of chewed wires and congested airways. Search for droppings, shredded material, or strange odors as initial indicators.
Mesh screens or elevated borders can act as a barrier to evict unwanted visitors.
5. The Manufacturer’s Take
Most manufacturers simply don’t recommend covering AC units in winter. They cite moisture build-up as their primary concern.
If you ignore these tips, you could endanger your warranty and unit health. Technician visits to get the unit serviced will make it as efficient as possible, covered or not.
Minnesota’s Winter Reality
Winter in Minnesota is infamous for its extended periods of frigid temperatures and deep snow. Minnesota’s winter reality hits between December and February, when the temperature can dip anywhere from 14°F to 30°F (-10°C to -1°C). Some days have just five to six hours of sunshine, and blizzards and/or ice storms are likely to occur more than once during a season. This weather defines everything – from the way we drive to the way we tend to outdoor equipment, such as air conditioners.
Outdoor AC units are designed to contend with rough weather, but Minnesota’s winter presents some additional challenges. The cold, itself, is not the big issue. Most AC systems are designed to handle freezing air when they’re off. The trouble is caused by snow, ice and debris that can accumulate around the unit. When snow accumulates, it can obstruct airflow or bend over the metal fins. Thick ice can form during storms, which can weigh down portions of the unit and cause damage if left uncleared.
The sunless, short winter days imply that snow and ice sometimes stick around for weeks. This can make it difficult to detect harm until it has progressed. Some folks still have to contend with power outages after large storms, leaving them unable to monitor outdoor equipment for days. These days it’s so easy for snow and ice to build up without anyone realizing it.
If you’re a Minnesotan, winter prep is life. Preparing the AC unit for the cold is an intelligent thing to do. This means raking out leaves and grass and sticks from around the unit before the snow flies. Trimming plants nearby keeps the area clean. It’s smart to verify that the unit is level, as shifting ground from freeze and thaw can sometimes cause it to tilt.
Others slap a plyboard or loose cover over the top to prevent heavy snow ingress but it’s crucial you don’t restrict the unit with tight wrapping. A snug cover can trap moisture, resulting in rust or mold.
Minnesota’s winter reality, it’s hard but wonderful to live in it. Winter is hard, who wants to drive on icy roads and shovel snow and deal with those long, dark evenings that get you down? Lots of people embrace the sunshine, with frozen lakes, skiing or skating. Whether confronting the cold with fear or elation, preparedness and knowing how to maintain your outdoor equipment is paramount.
The Right Way to Cover
Covering up your AC unit in a Minnesota winter isn’t always necessary, but if you do, the right way to cover counts. Today’s AC units can weather snow, wind, and cold. Still, some owners desire the extra reassurance or protection from fall debris and rough weather. The right way to cover prevents moisture, rust, or debris from being trapped. Below are effective methods:
- Buy a breathable cover for your outdoor units ($15 to $40).
- Protect the unit with an overhead canopy for shade and weather protection all year round.
- Select partial coverage to block leaves or seeds in fall.
- Uncover after storms or heavy snow to prevent moisture entrapment.
- Schedule routine maintenance as a first line of defense.
Breathable Materials
- Polyester mesh covers permit airflow and block debris.
- Canvas covers are tough and let moisture escape.
- Specialty AC covers marked “breathable” are ideal. Stay away from plastic tarps.
- Covers should fit loosely, not tight against the unit.
Avoid waterproof plastic or vinyl because it can trap condensation, causing rust and corrosion inside your AC. A breathable cover keeps moisture from becoming trapped, preventing mold or mildew.
Keep in mind, the cover should not obstruct the unit’s vents or drainage holes, as this impacts the internal components. Always test if the material can withstand wind, cold, and ice–some covers literally shred to pieces in a hard winter.
Partial Coverage
- Just cover the top of the unit, with a drape, leaving sides open.
- Take mesh or screen and keep the big debris out but don’t close off the airflow.
- Fasten covers loosely on corners, avoiding a full wrap.
Partial coverage allows air to circulate and keeps the unit dry. In covering just the top, you shield delicate components such as the fan or electrical controls from falling limbs or ice chunks yet eschew trapped moisture.
This way is convenient in the fall, keeping out seeds and leaves without having to trap moisture inside. Partial covers protect from dents or damage by winter storms. They’re easy to take down or put up after a rough storm, minimizing the chance of rust or pooling. That’s typically sufficient for snow pile-up climates.
Secure Fastening
A cover only works if it stays on. Tie covers with soft cords or stones to secure down during high wind. Inspect your cover after each storm to ensure it hasn’t shifted or ripped.
Do not use nails, screws, or anything that might scratch or damage your AC. Opt for bungee cords, fabric straps, or weighted edges instead.
Better Winter Prep
Preparing your AC unit for winter is not difficult, but it does require some maintenance. Most outdoor units are constructed with robust metals and a rugged finish. These babies will take care of snow, ice and cold. They shouldn’t require covers to shield them from the elements.
Indeed, capping can be more injurious than beneficial. Covers can capture moisture-laden air. When the temperature gets cold, this trapped water can freeze on the coils and damage the unit. It provides an excellent nesting site for rodents. Mice and small animals crave warm, dry places in winter, and a covered AC unit provides just that.
This can result in chewed wires and scars. Captivity moisture over the winter can clog airflow come summer. This means your AC may not work as well when you need it most!
To make sure your unit is ready for winter, follow this simple checklist:
- Plan an annual visit from a qualified HVAC technician. It’s hands down one of the best ways to maintain your AC. Your technician can catch little issues before they become large, expensive ones. They ensure the unit is clean and all components function as they should.
- Tidy up around your outdoor unit. Remove leaves, twigs and dirt that may have accumulated – these tend to clog air vents or cause rust. If your region receives a lot of leaves or seeds, a quick inspection once a week will suffice.
- Inspect all electrical components and wiring. Check for wear, rust or loose wires. If you spot anything awry, get it repaired before the weather goes downhill. This step can prevent a little problem from becoming a major pain.
- Ensure that the unit is unobstructed on all sides. Provide at least 60cm of open space surrounding the unit. This facilitates good air flow and prevents snow and ice accumulation immediately adjacent to the unit.
Others blanket their AC to prevent leaves and junk from getting in. While this might seem like a good idea, it’s typically unnecessary. These units are designed to withstand this type of mess.
Routine inspections and some TLC do a better job and keep potential hazards low.
The Ice Dam Dilemma
Ice dams are a bane in winter wonderlands. They develop when snow on a roof melts, runs down to the edge, then freezes again into an ice band. This impedes more melting snow from draining and causes water to back up under the shingles and leak into the structure.
The entire situation is further aggravated by uneven roof heating caused by inadequate insulation, insufficient ventilation, or a roof design that traps heat in certain areas. In areas where snow accumulates, ice dams can wreak havoc on both the roof and HVAC systems in their vicinity.
In the case of AC units, ice can be more than an eyesore. If ice builds up around or on top of the unit, it can prevent airflow. This forces the unit to work harder when it fires up in spring, which can reduce its efficiency and even reduce its lifespan.
It’s dangerous because water from melting snow or ice can soak into tiny crevices, refreeze and break components within the unit. This freeze/thaw cycle is hard on metal, plastic and wires. As if the ice dam dilemma weren’t enough, sometimes these ice dams drip water directly on top of the AC unit, exacerbating the issue. If water gets inside, it can result in rust, mold, or electrical problems.
It’s safest to monitor weather changes closely to identify periods when ice dams can be anticipated. When snow is heavy and the temperature fluctuates, you’re at greater risk. Homeowners are able to anticipate and clear snow from their roof or around the AC unit.
Using a roof rake (a long handled tool for pulling snow down safely) is a great way to keep the roof clear without having to climb up. If you live in a heavy snow belt, it can be worth it to hire a pro to remove the roof or inspect your insulation and ventilation — a great investment in the long run.
Here’s a quick look at ways to keep ice from building up around your AC:
| Strategy | What to Do | Why It Helps |
|---|---|---|
| Clear Snow Off the Roof | Use a roof rake after snowfalls | Stops ice dams from starting |
| Add Insulation | Insulate attic and roof spaces | Keeps roof temperature steady |
| Improve Ventilation | Make sure attic vents are clear | Reduces warm spots on the roof |
| Direct Water Away | Set gutters to move water from the house | Stops water from pooling by unit |
| Cover the AC Unit (Optional) | Use a breathable cover, not plastic | Blocks snow but lets air move |
| Check Weather Often | Watch for warm days after snow | Act fast if ice starts to build |
Preventing ice dams saves you money and angst repairing leaks.
Your Spring Startup
Spring means that we’re turning from heating to cooling, and your air conditioner needs a seamless transition ward after months of winter. Tearing off the band-aids is step one. Whether it’s tarp or plastic sheeting, sheets of plywood or a MacGyver type shield. If you installed a cover for debris or ice shield, remove it completely prior to the first warm spell. Covers retain moisture and water that’s trapped can freeze, causing rusty or bent coils.
Others discover rodents burrowing beneath covers, so check for nests or droppings and clear away at the foot of the unit. Then, have your AC unit fully inspected and serviced. While outdoor air conditioners are designed to withstand snow, rain, and cold, a professional check can help you catch problems before they become big. A technician searches for telltale signs of wear, such as bent fins or loose wires, and can identify damage from rodents or lingering debris.
If you employed plywood or a custom shield to protect from falling branches, inspect to see if the external cabinet was scratched or dented. The metal housing is sturdy—engineered to deflect limbs and debris—but scoping it for vulnerabilities is prudent. If you heat and cool with a heat pump, never cover it in winter. This allows air to flow and prevents performance dips.
If you do one thing, clean or swap out those filters – key for good airflow and cooling. Dirty filters make your unit labor more and that means more energy and less cooling. Replace single-use filters or clean washable ones, depending on your unit’s manufacturer. If you blew off filter changes last season, do it now.
Airflow obstructions from dust or remaining leaves can impede cooling and even strain the compressor. Look around the top and sides of the outdoor unit for any leaves, twigs or trash that got trapped over winter. Scrape away grass or weeds from the base, as well.
Last step: test your AC before it’s needed for daily use. Flip it on one mild day and leave it running for 10-15 minutes. Listen for weird noises, look for unusual odors and make sure that cool air is blowing from inside vents. If the system gives you a hard time or the air is hot, call a repair man.
Early testing provides time to repair issues before the heat of summer arrives, meaning you’re not stuck waiting on repairs during peak season.
Conclusion
To protect your AC during a Minnesota winter, ditch the covers. Moisture and trapped ice are worse than open air. A top cover or board can block falling ice or snow. Weigh it down with a couple of bricks or stones. Rake leaves and dirt away from its base before winter knocks. Inspect for leaks or loose wiring in the spring. Quick action today prevents major fixes down the line. For more stress-cutting, cash-saving tips, contact your local pro or consult your unit’s manual. Keep it simple, keep ahead of the small stuff, and your AC will last longer. Need more home care assistance? Check out more guides and tips in our other posts.
Frequently Asked Questions
Should I cover my AC unit during a Minnesota winter?
Should you fully cover your AC unit during a Minnesota winter? Most newer units are designed to withstand snow and cold. Covering can trap moisture and rust or mold.
What are the risks of covering my AC unit in winter?
Wrapping your AC unit can create a moisture trap that causes rust, mold and pests. It can obstruct airflow, potentially harming the unit. Cover only if your manufacturer suggests it.
How can I protect my AC unit in extreme cold?
Remove snow and debris from the unit. Just be sure the top is clear of ice and leaves. Don’t use plastic or airtight covers, which trap moisture.
Is there a safe way to cover an AC unit?
If you insist on covering your AC, cover it with a breathable, waterproof cover made for AC units. Just cover the top to keep out falling crap, don’t do the sides. Take the cover off in early spring.
Will winter weather damage my AC unit?
Most AC units are built for inclement weather, even Minnesota winters. Snow and ice typically won’t damage them. Damage tends to come from trapped moisture or debris, NOT winter itself.
What should I do before using my AC in spring?
Take off any cover and look for debris or damage. Remove leaves and debris. Check for animal nests. Schedule a professional check-up for peak performance.
Can ice dams affect my AC unit?
Ice dams on your roof won’t hurt your AC unit. Water runoff can pool around the unit, causing damage. Ensure the area surrounding your unit drains well.