Save Your Unit: Why Cover Air Conditioner In Winter?

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Should you cover central air conditioner in winter? For most homes, yes, covering your outdoor AC unit is a good idea. It’s a smart way of protecting AC from winter weather damage. Taking a little time to cover your unit before cold weather arrives can save you money and trouble later. It helps keep your AC running well for many years.

Why Cover Air Conditioner In Winter
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Grasping Winter’s Impact on AC Units

Winter weather is tough. It brings cold, wind, rain, snow, and ice. Your outdoor air conditioner unit sits outside through all of this. It is built to handle weather, but some parts are sensitive. Letting winter elements directly hit your unit month after month can cause problems.

The Force of Snow and Ice

Snowfall can be heavy. It lands on top of your unit and around it. If it melts a little and then refreezes, it turns to ice. Ice is hard and expands when it forms.

  • Heavy snow can push down on the top grille or fan blades. This might bend or break parts.
  • Ice can build up around the base. It can get into small spaces. As ice expands, it can crack plastic or even metal parts.
  • Melting snow and ice can pool water. This water can then freeze again, making the problem worse.
  • This causes damage to AC from snow and ice. It is a major risk of not covering AC in winter.

Wind and Flying Debris

Winter winds can be strong. They blow leaves, twigs, dirt, and other junk around.

  • Wind can push debris into the side fins of your unit. The fins are thin metal pieces that help the unit work right. If they get bent or clogged with leaves, the unit cannot cool well when summer comes.
  • Small stones or branches blown by the wind can hit the unit and cause dents or scratches. This might seem small, but scratches can lead to rust later.

Wetness and Corrosion

Rain, melting snow, and ice introduce a lot of water. Metal parts, especially screws, bolts, and the cabinet itself, are prone to rust when constantly wet.

  • Rust weakens metal. It can make screws harder to remove for service.
  • Rust can spread. If it starts on the outer shell, it can creep into other parts.
  • Prevent rust on outdoor AC unit is a key reason to cover it. Constant wetness from winter weather makes rust much more likely.

Critter Concerns

Cold weather sends small animals looking for shelter. Your outdoor AC unit can look like a good place to hide.

  • Mice, rats, squirrels, and other pests might build nests inside the unit. They can chew on wires or insulation.
  • This can cause electrical problems or damage to internal components.
  • A cover can help deter some of these unwelcome guests.

Thinking about these points shows the risks of not covering AC in winter. It is not just about keeping the unit clean. It is about protecting it from physical harm and moisture damage over several cold months.

Appreciating the Benefits of Covering

So, why go through the step of covering your AC unit? The benefits of covering outdoor AC unit during the off-season are clear and can save you from costly repairs.

Shielding from Harsh Elements

The most direct benefit is protection. A good cover acts as a barrier.

  • It stops snow and ice from piling up on top and around the base.
  • It keeps wind-blown leaves, sticks, and dirt out of the fins and internal parts.
  • It prevents constant rain and moisture from sitting on metal surfaces, which helps prevent rust on outdoor AC unit.

This simple shield keeps the unit cleaner and drier. It reduces the direct impact of winter’s worst.

Preventing Physical Damage

By keeping heavy snow loads off and blocking flying debris, a cover reduces the chance of parts getting bent, broken, or dented.

  • Fan blades are protected from falling ice or branches.
  • The top grille stays safe from heavy weight.
  • The thin fins on the sides are less likely to get clogged or bent by blown materials.

Less physical damage means fewer things to fix when spring comes.

Keeping Out Pests

While not a perfect barrier, a cover makes your AC unit less appealing to animals seeking warmth and shelter.

  • It can make it harder for them to get inside.
  • It reduces the open space they might see as a cozy home.
  • This lowers the risk of chewed wires or nesting material causing blockages.

Extending Unit Lifespan

All these protective steps add up. By preventing damage from weather, debris, moisture (rust), and pests, you reduce wear and tear on the unit.

  • Parts are less likely to corrode or break down over the winter.
  • The unit starts the new season in better shape.
  • This means it might need fewer repairs over time.
  • It also helps the unit run more efficiently for longer.
  • Ultimately, protecting AC from winter helps extend AC unit lifespan. This means you get more years of service from your investment before needing to buy a new one.

Easier Spring Startup

When it is time to use your AC again, a covered unit will be in much better condition.

  • It will likely be cleaner inside and out.
  • There will be less debris to clear away.
  • You can start it up with more confidence that winter hasn’t caused hidden damage.

Winterizing air conditioner unit by covering it is a small task with big potential payoffs. It is an easy step to protect your property and your wallet.

Deciphering the Best Way to Cover

Simply throwing anything over the unit is not the best plan. The wrong cover or method can actually cause problems. Knowing the best way to cover AC for winter is important.

Not All Covers Are Equal

Covers come in different materials and styles. Choosing the right one matters.

  • Solid Plastic or Tarp Covers: These stop all moisture from above. However, they trap moisture inside the unit. As temperatures change, condensation can form. This trapped dampness is bad for metal parts and can actually speed up rust. They also stop air circulation, which can encourage mold or mildew growth. Avoid using full, non-breathable covers.
  • Partial, Breathable Covers: These are usually made of mesh or a special fabric. They cover only the top of the unit, stopping snow, ice, and large debris. But they leave the sides open. This allows for air to move through the unit. Any moisture that gets inside can dry out. This is generally considered the best way to cover AC for winter for central air units.
  • Purpose-Built AC Covers: Many companies make covers specifically for AC units. These often use breathable, durable materials and are sized to fit standard units. Some cover the full unit but are made of breathable fabric. Check reviews and product descriptions carefully.

What Size and Shape?

The cover should fit your unit well.

  • For partial covers, measure the top of your unit to get the right size square or rectangle.
  • For full covers (if using a breathable type), measure the height and width/depth.
  • A cover that is too small won’t protect properly.
  • A cover that is too large can flap in the wind, potentially damaging the unit or tearing the cover itself. It can also let snow blow in underneath.
  • Look for covers with straps or elastic hems to secure them tightly against wind.

Preparing the Unit Before Covering

Before you put any cover on, you need to prepare the unit. This is part of winterizing air conditioner unit properly.

  • Step 1: Clean the Unit:
    • Turn off the power to the unit first! Find the outdoor shut-off switch (usually a box near the unit) and flip it off.
    • Remove any large debris from around the base of the unit, like leaves or weeds.
    • Carefully remove the top grille (check your owner’s manual for how).
    • Gently remove any leaves, twigs, or dirt from inside the unit. You can use your hands or a soft brush. Be careful not to damage wires or parts.
    • Look at the fins on the sides. If they are clogged with dirt or cottonwood fluff, you can use a soft brush or a gentle spray from a garden hose to clean them. Spray from the inside out if possible to push dirt away. Be very gentle, the fins bend easily.
    • Put the top grille back on securely.
  • Step 2: Shut Off Power (Double Check): Make sure the power is off at the outdoor switch. Some people also turn off the circuit breaker inside the house that controls the AC just to be extra safe. Tape the switch or breaker in the “off” position so no one turns it on by accident while the unit is covered or not ready. Running the AC with a cover on can damage it severely.
  • Step 3: Inspect: While cleaning, look for any obvious signs of damage. Are wires chewed? Are parts loose? Note anything that might need fixing before next season.

The Covering Process

Once the unit is clean and the power is off, you can add the cover.

  • Place the cover on the top of the unit.
  • If it’s a partial cover, make sure it sits flat and covers the entire top surface.
  • If it’s a full cover (breathable type), pull it down over the sides.
  • Secure the cover using the straps, buckles, or drawstrings it came with. Make it snug so it won’t blow off in strong winds, but not so tight that it might tear.
  • The goal is to keep snow and ice off the top and large debris out, while allowing air movement if using a breathable cover.

This careful process ensures you are winterizing air conditioner unit in a way that provides real protection.

Focusing on Different Unit Types

The best approach can be slightly different depending on the type of air conditioner you have.

Central Air Conditioner Outdoor Unit

This is the large box that sits outside your house.

  • As discussed, the general recommendation is to use a partial, breathable cover that just covers the top.
  • This type of cover stops snow, ice, and debris from falling inside from above.
  • It allows air to circulate through the sides. This lets moisture escape and prevents condensation buildup inside the unit.
  • Many HVAC professionals suggest only covering the top or not covering at all in some mild climates, arguing that the units are designed to be outdoors. However, a top cover offers clear benefits against falling debris and heavy snow/ice loads on the fan area.
  • If you live in an area with severe winters, heavy snowfall, or lots of trees that drop debris, covering the top is highly recommended for protecting AC from winter elements.
  • Remember to clean the unit and shut off power before covering.

Covering Window AC Unit for Winter

Window units are handled differently than central air units. They are exposed to weather from all sides and also create a gap in your home’s insulation.

You generally have two main options for covering window AC unit for winter:

  1. Remove the Unit: This is often the best option if possible.

    • Window units are heavy, so get help.
    • Carefully remove the unit from the window.
    • Clean the unit well. Remove filters, vacuum dust.
    • Store the unit in a dry place like a garage or basement. Cover it with a sheet to keep dust off.
    • Seal the window opening where the unit was installed. This is crucial for preventing drafts and heat loss. Use insulation boards, caulk, or weather stripping.

  2. Leave the Unit in the Window: If the unit is too heavy to remove or is permanently installed, you must winterize it in place.

    • Seal from the inside: This is the most important step if leaving it in. Cold air will come through the unit and around its edges.
      • Use foam insulation strips or special AC insulation panels to fill gaps around the unit in the window frame.
      • Use heavy-duty tape designed for outdoor use to seal seams around the unit from the inside.
      • Consider getting an indoor AC cover designed for window units. These are often fabric or plastic bags that go over the inside part of the unit, sealing it off from your room and improving insulation.
    • Cover from the outside: Get a purpose-made outdoor cover for window AC units.
      • These are typically vinyl or heavy fabric bags that go over the outside of the unit.
      • They often have drawstrings or straps to secure them.
      • The cover protects the unit from rain, snow, and debris.
      • Make sure the cover allows any drainage holes on the bottom of the unit to remain clear, following the manufacturer’s instructions. Trapping water inside can cause freezing and damage.

Winterizing air conditioner unit when it is a window unit involves both protecting the unit itself and sealing your home from the cold air it can let in.

Considering Other Winterization Steps

Covering is a key part of winterizing air conditioner unit, but there are a couple of other things to consider.

  • Professional Check: Before winter, or in early spring, consider having an HVAC technician inspect your unit. They can spot potential issues, check refrigerant levels (this is not something a homeowner should do), and make sure the unit is in good shape. This is especially wise before covering it for a long period.
  • Clear the Area: Keep the area around your outdoor unit clear year-round, but especially before winter. Remove leaves, branches, and anything else that could blow into or onto the unit. This helps with air flow when running and reduces debris risk in winter.
  • Rodent/Pest Control: If you’ve had issues with pests, take steps to deter them from the area around the unit. This could include removing attractants or using repellents (make sure they are safe for pets and the environment).

Taking these steps along with choosing the best way to cover AC for winter ensures your unit is fully prepared for the cold months.

Addressing Common Questions

Here are answers to some questions people often ask about covering their AC unit for winter.

h4: Does covering the whole unit trap moisture?
Yes, full covers made of non-breathable materials like solid plastic or tarps can trap moisture inside. This can lead to condensation, rust, and even mold. It is better to use a partial, breathable cover that only covers the top, allowing air circulation. Or use a full cover made of breathable fabric.

h4: Can I just use a cheap tarp to cover my unit?
Using a cheap, non-breathable tarp is not recommended. While it keeps snow off, it will likely trap moisture inside the unit. This can cause more harm than good by promoting rust and corrosion. It is better to invest in a proper, breathable AC cover, or use a partial cover.

h4: When should I cover my AC unit?
You should cover your outdoor AC unit after you have finished using it for the cooling season and before heavy snow or ice is expected. This is usually in the late fall, after the first hard freeze in your area.

h4: When should I uncover my AC unit?
You should uncover your unit in the spring, before you need to use it for cooling. After uncovering, inspect it, clean off any dust or debris that may have gotten under the cover, and make sure the power switch is turned back on before starting the unit.

h4: Will covering my unit prevent rust?
A proper, breathable cover, especially a partial top cover, helps prevent rust on outdoor AC unit by keeping direct rain and melting snow/ice off key metal surfaces. By limiting constant moisture contact, it significantly reduces the risk of corrosion compared to leaving it fully exposed.

h4: Do I need a professional to cover my AC?
No, covering your AC unit is generally a simple task you can do yourself. The main steps are cleaning the unit, turning off the power safely, choosing the right cover, and securing it properly. If you are unsure about turning off the power or cleaning inside the unit, you might ask a professional for help with winterization.

h4: What if my AC manufacturer says not to cover the unit?
Some manufacturers say their units are built to withstand all weather and do not need covering. In this case, follow the manufacturer’s recommendation. However, many homeowners in areas with heavy snow, ice, or lots of falling debris still choose to use a partial cover just on the top to prevent physical damage to the fan area, which is often an acceptable compromise. Always check your specific unit’s manual.

Final Thoughts

Winterizing air conditioner unit is a simple, cost-effective step for protecting AC from winter. While AC units are built tough, the harsh elements like heavy snow, ice, wind, and constant moisture can cause damage over time. Risks of not covering AC in winter include rust, bent parts, and pest infestations.

By choosing the best way to cover AC for winter – usually a breathable, partial cover for central air units – you can shield the unit from the worst conditions. This helps prevent rust on outdoor AC unit, avoids damage from snow and debris, deters pests, and keeps the unit cleaner.

Ultimately, taking this small step helps extend AC unit lifespan, reduces the need for repairs, and ensures your unit is ready to cool your home efficiently when warmer weather returns. It is a smart move for any homeowner looking to protect their investment.