Can You Leave A Window Air Conditioner In All Winter: Risks, Maintenance, And Expert Advice

Many homeowners wonder, is it safe or practical to leave a window air conditioner installed over the winter? Decisions about removing or covering AC units can impact home comfort, energy efficiency, and equipment longevity. This guide details the risks, best practices, and expert recommendations for managing window AC units once cold weather arrives.

Factors To Consider Before Leaving A Window Air Conditioner In Over Winter

When temperatures drop, window AC units become dormant, but their presence can still affect your home. Several important factors should guide your decision about leaving them in place:

• Energy efficiency and drafts: Window ACs can cause heat loss in winter if not properly sealed.
• Weather exposure: Units may face snow, ice, wind, and moisture, risking potential damage.
• Security risks: A window AC can be an entry point for intruders.
• Maintenance issues: Accumulated moisture may promote mold, rust, or pest infestations.

Evaluating these aspects helps determine the safest and most cost-effective strategy for your home and appliance care.

Potential Risks Of Leaving A Window AC In All Winter

Leaving a window air conditioner installed during freezing months involves trade-offs. Consider these critical risks:

1. Heat Loss & Higher Energy Bills

Window AC units often create gaps between the unit, window frame, and accordion panels. In winter, these air leaks can let warm air escape and cold air enter, causing:

• Decreased indoor comfort
• Increased heating costs
• Additional wear on home heating systems

2. Water, Snow, And Ice Intrusion

Exposed units can suffer from weather ingress. Melting snow and ice may drip inside the AC, leading to:

• Internal corrosion
• Mold and mildew growth
• Damage to electrical components

3. Structural Stress On Window And Frame

Leaving the unit in place puts year-round stress on window sashes, balances, and frames, especially during high winds or ice buildup. This can cause warping, cracking, or other window damage.

4. Pest Infestation

Cracks or weakened seals around window ACs can invite insects or rodents into your home during cold months.

5. Premature Equipment Wear

Continuous exposure to freezing temps, precipitation, and debris can lead to faster wear and a shorter life span for your air conditioner.

When Is It Safe To Leave The AC Installed?

There are situations where customers decide to leave their window air conditioner in place for winter. Here’s when it’s generally acceptable:

• If removing and reinstalling is difficult—such as with large, heavy units or on upper floors.
• If your building regulations or homeowner’s association allows the unit to remain in all year.
• If you perform proper winterization to protect the AC and the integrity of the window opening.

However, *it is always recommended* to consult your AC manufacturer’s manual or your landlord/property manager for specific guidance relevant to your appliance and building.

Best Practices For Winterizing A Window Air Conditioner

For those who decide—or are required—to keep their AC installed, winterization is crucial. Here’s what experts recommend to minimize potential harm:

1. Clean The Unit Thoroughly

Remove filters, wash them, and let them dry fully. Wipe down all exposed surfaces to prevent dirt buildup and discourage mold growth.

2. Seal All Gaps And Cracks

• Use foam insulation strips around the perimeter of the AC and accordion panels.
• Consider removable caulk for a tighter, temporary seal.
• Pay extra attention to the bottom and sides where cold air may leak.

3. Install A Weatherproof Cover

Specially designed exterior AC covers protect the unit from snow, ice, and debris. Do not use plastic bags or tarps, as they can trap moisture and promote mold or rust.

4. Secure The Unit

• Check brackets and mounting hardware for sturdiness.
• Ensure the unit is not loose, which can cause shifting or gaps.

5. Inspect Periodically

Regularly check the unit after storms or heavy snow to clear away ice buildup and look for signs of water intrusion or draftiness.

Should You Remove A Window AC For Winter?

Most HVAC professionals recommend removing window air conditioners for winter if possible.

• Proper storage protects ACs from the elements, extending life and performance.
• Sealed windows are more energy efficient, providing better insulation.
• Eliminating the window obstruction improves security and aesthetics.

Step-By-Step Guide: How To Remove And Store A Window Air Conditioner

If you choose to remove your AC for the winter, follow these steps for safe handling and storage:

1. Turn Off And Unplug The Unit

Ensure the appliance is unplugged and no power is running before proceeding.

2. Remove The Front Grille And Filter

Clean the grille and filter. Let them air dry completely before storage.

3. Detach The AC From The Window

• Follow the installation manual to remove securing hardware and the accordion panels.
• Get help for larger or heavier units to avoid injury.

4. Drain Excess Water

Tilt the unit gently to empty any water that may be trapped in the base pan to prevent mold over the winter.

5. Clean And Dry The Unit Thoroughly

• Wipe the exterior and interior with a dry cloth.
• Let the unit air out for several hours before storing it.

6. Store In A Dry, Temperature-Controlled Area

Keep the AC upright on a flat surface to preserve internal components. Cover loosely with a breathable cloth to avoid dust accumulation but allow moisture to escape.

Alternatives: When You Can’t Remove The Unit

If removal isn’t practical, *enhancing insulation and protection is key*:

• Heavy-duty AC covers (exterior) to block precipitation and wind.
• Magnetic or foam interior insulator panels to boost draft protection.
• Weatherproof tape or removable caulk for all gaps and seams.

Even with these precautions, monitor both the condition of the AC and the temperature around your windows throughout the season.

FAQ: Leaving A Window Air Conditioner In Over Winter

Question	Answer
Can all window ACs be left in over winter?	No. Some models are less weather-resistant or easier for intruders to remove. Check your model’s manual.
Will my AC still work next summer?	If properly winterized, most units will work, but some may suffer corrosion or mold that affects performance.
Can leaving a window AC installed cause health issues?	If moisture accumulates inside the AC, it may cause mold, contributing to allergy or asthma symptoms.
What about portable ACs with window kits?	Remove and store window vent kits for portable ACs in the winter for better insulation and less wear.

Energy Efficiency Impacts Of A Window AC In Winter

One of the major downsides to keeping a window air conditioner in place all winter is its effect on your home’s energy usage. Details include:

• Heat escapes easily through unsealed joints and around accordion panels, especially in older units.
• Heaters must work harder to compensate for lower indoor temperatures, costing you more monthly.
• Home Inspections: Many energy auditors note window ACs as significant sources of winter heat loss.

Typical Manufacturer Recommendations For Winter Storage

Most leading AC manufacturers, including Frigidaire, GE, LG, and Whirlpool, advise removing and storing window units when winter arrives unless they’re specifically designed for year-round use. *Reference your user’s manual for exact instructions.*

• Store indoors, upright, and in a dry location.
• Clean filters and unplug during storage.
• Never operate the AC below manufacturer-specified minimum temperature (usually 60°F or 16°C).

Winterizing Your AC: Common Mistakes To Avoid

Avoiding these missteps ensures proper protection for your air conditioner:

• Do not wrap the AC in a non-breathable plastic sack (traps moisture).
• Avoid leaving accordion panels extended without added insulation—these are not weatherproof.
• Never rely solely on interior covers without sealing outside gaps.
• Failing to empty trapped water can prompt mold or frost damage.

Expert Tips To Maximize AC Longevity

Keeping your window air conditioner in top condition—even if left in the window—comes down to these expert-approved strategies:

1. Always inspect seals and insulation before and after winter storms.
2. Use covers made specifically for window AC units to avoid moisture and wind penetration.
3. Schedule an annual cleaning and tune-up every spring.
4. Replace compromised or deteriorating insulation promptly.
5. Store removed units on a shelf, not on basement floors (to avoid flooding hazards).

Local Building Codes And Regulations

Some cities and HOAs restrict leaving window air conditioners installed through winter months, especially if they project onto walkways or pose safety risks. Always:

• Check with local building department before winter to avoid violations.
• Ensure your installation doesn’t obstruct fire escapes or emergency exits.

Summary: Weighing The Pros And Cons

Option	Benefits	Drawbacks
Leaving AC In Window	Convenience, avoids heavy lifting	Risk of leaks, higher heating bills, AC damage
Removing And Storing AC	Improved home insulation, extends AC lifespan	Requires effort, must have storage space
Winterizing In Place	Compromise; protects AC if removal not possible	Still risks some drafts and moisture entry

Making an informed decision about winter management of your window air conditioner protects your investment, saves energy, and keeps your home comfortable all year round. The best approach depends on your building, equipment, and willingness to maintain protective measures through the cold season.