Properly covering your window air conditioner during winter months is essential for protecting your investment and preventing weather damage. A well-covered AC unit can last years longer than one left exposed to harsh winter elements. Not only does covering your unit shield it from snow, ice, and moisture, but it also helps prevent cold drafts from entering your home, potentially lowering your heating bills. This guide explores various covering options, proper installation methods, and maintenance tips to ensure your window air conditioner remains in optimal condition during its off-season.
Window air conditioners are vulnerable to winter weather conditions that can cause significant damage. Moisture from snow and rain can lead to rust and corrosion of internal components, potentially reducing efficiency or causing complete failure when summer returns. Freezing temperatures can crack coils and damage the unit’s compressor.
Covering your AC also prevents cold air infiltration through the unit’s vents and gaps, helping maintain your home’s warmth during winter months. Additionally, a proper cover blocks debris like leaves, twigs, and dirt from accumulating inside the unit, which could otherwise cause clogs or damage when you restart the air conditioner in warmer weather.
Protected units typically have extended lifespans, saving you money on premature replacements. Many manufacturers actually recommend covering window units during off-seasons to maintain warranty validity and ensure optimal performance when the unit is needed again.
Types of Winter Covers for Window Air Conditioners
The market offers various cover options to suit different needs and budgets. Outdoor covers are typically made from weather-resistant materials like vinyl, polyester with water-resistant coating, or marine-grade canvas. These materials provide protection against moisture, UV rays, and extreme temperatures.
Indoor covers focus more on preventing drafts and typically use insulated materials. These are ideal if you choose to keep your unit installed but want to prevent cold air infiltration. Some covers combine both indoor and outdoor elements for comprehensive protection.
| Cover Type | Materials | Average Cost | Best For |
|---|---|---|---|
| Basic Outdoor Cover | Vinyl or polyester | $15-30 | Basic weather protection |
| Premium Outdoor Cover | Heavy-duty vinyl with UV protection | $30-60 | Extreme weather conditions |
| Indoor Insulated Cover | Insulated fabric with foam backing | $20-40 | Draft prevention |
| Custom-Fit Cover | Various materials made to unit specifications | $40-100+ | Perfect fit for specific models |
When selecting a cover, consider your climate conditions and whether your unit remains installed year-round. Custom-fit covers typically provide the best protection as they’re designed for specific AC models, but universal covers can work well if properly secured.
Step-by-Step Guide to Properly Cover Your Window AC
Properly covering your air conditioner involves more than simply throwing a cover over it. Follow these steps for maximum protection:
- Clean the unit thoroughly – Remove dust, debris, and any moisture before covering
- Inspect for damage – Check for loose parts, rust, or issues that should be addressed before storage
- Run a final dry cycle – Turn the unit on “fan only” mode for 30 minutes to dry internal components
- Remove debris from vents – Ensure all openings are clear of obstructions
- Apply the cover – Stretch it over the entire unit, ensuring a snug fit
- Secure the cover – Use the provided straps, drawstrings, or add bungee cords for extra security
- Seal any gaps – Ensure no openings remain where moisture or pests could enter
For units that remain installed, consider adding weatherstripping around the perimeter where the AC meets the window frame. This provides additional insulation and prevents cold air infiltration. Proper coverage should include both the exterior and interior portions of the unit for complete protection.
Additional Securing Methods
In areas with high winds, standard securing methods may be insufficient. Consider adding additional protection like duct tape around edges (if it won’t damage surfaces) or installing small wooden blocks on the windowsill to prevent the cover from slipping off. For extremely harsh conditions, some homeowners add a secondary tarp over the primary cover for additional protection.
DIY vs. Commercial AC Covers: Which Is Better?
While commercial covers offer convenience and purpose-built designs, DIY solutions can be effective alternatives. Store-bought covers typically provide more reliable protection due to their waterproof materials and reinforced seams specifically designed for outdoor conditions.
However, DIY covers can be cost-effective options if made with appropriate materials. Heavy-duty tarps, marine canvas, or insulated fabrics can work well when properly secured. The key is ensuring complete coverage and proper sealing against moisture.
| Aspect | Commercial Covers | DIY Solutions |
|---|---|---|
| Average Cost | $15-60 | $5-30 (materials) |
| Durability | Generally high, designed for multiple seasons | Varies based on materials used |
| Fit | Available in universal or custom sizes | Can be customized but may lack finishing details |
| Weather Resistance | Purpose-designed for water resistance | Depends on materials; may need additional waterproofing |
| Ease of Use | Ready to use with built-in fastening systems | Requires assembly and may be cumbersome to install |
For DIY covers, consider using materials like heavy plastic sheeting (6 mil or thicker), wrapped and taped securely, or a combination of bubble wrap covered with waterproof material. Always include a method to secure the cover against wind, such as cord or bungee attachments.
Additional Winter Protection Tips for Window AC Units
Beyond simply covering your unit, consider these additional protection measures. Removing the unit entirely offers the most comprehensive protection if you have storage space available. Store the AC in a dry, temperature-controlled environment after cleaning and drying thoroughly.
If removal isn’t feasible, consider adding insulation around the unit. Foam insulation boards can be cut to fit around the perimeter where the AC meets the window frame. This helps prevent cold air infiltration and protects the unit from extreme temperature fluctuations.
- Apply a rust inhibitor to metal components before covering
- Place moisture-absorbing products inside the unit before covering
- Consider installing an interior air conditioner cover in addition to the exterior one
- Remove and clean the air filter, storing it separately
- Check on the unit periodically throughout winter to ensure the cover remains secure
For window units that have been in place for several years, winter is an ideal time to check the mounting brackets and support structures for signs of wear or damage. Replace any rusted or weakened components before the next cooling season begins.
When to Remove Winter Covers
Timing is crucial when it comes to removing your AC cover. Premature removal can expose your unit to late-season storms, while leaving the cover on too long can trap heat and moisture, potentially damaging the unit.
Generally, wait until after the last expected frost date in your area. In most northern regions, this means waiting until at least late April or early May. Southern regions may safely uncover units in March. Monitor weather forecasts for unusual late cold snaps before uncovering.
When temperatures consistently remain above 60°F and you’re approaching the time you might need your air conditioner, it’s appropriate to remove the cover. After removal, allow the unit to “breathe” for 24-48 hours before operating it to ensure any trapped moisture evaporates.
Transitioning to Spring Use
Once you remove the cover, perform a brief inspection of the unit. Look for any signs of winter damage, pest intrusion, or moisture issues. Clean the exterior of the unit, removing any debris that may have accumulated despite the cover. Check vents to ensure they’re clear and unobstructed.
After uncovering, wait at least 24 hours before turning on the unit to allow any internal components to reach ambient temperature. This helps prevent compressor damage that could occur from starting the unit when components are at different temperatures.
Common Mistakes to Avoid When Covering Window ACs
Many homeowners make critical errors when winterizing their air conditioners. Covering a dirty unit is perhaps the most common mistake, as trapped debris can hold moisture against metal components, accelerating corrosion. Always clean thoroughly before covering.
Using improper materials like ordinary household plastic or non-waterproof fabrics can actually cause more harm than good. These materials often trap moisture rather than repelling it, creating a damaging environment for the unit’s components.
Another frequent error is inadequate securing of the cover. Covers that blow off during storms leave your unit exposed precisely when protection is most needed. Use strong fastening methods that can withstand winter winds and precipitation.
- Covering without cleaning and drying the unit first
- Using materials that aren’t waterproof or weather-resistant
- Failing to secure the cover adequately
- Covering a unit that’s still connected to power (always unplug first)
- Creating an airtight seal that prevents some airflow (this can trap moisture)
- Forgetting to cover both indoor and outdoor portions of the unit
- Neglecting to check the cover throughout winter
Some homeowners mistakenly believe that covering only the exterior portion is sufficient. However, the interior portion often needs protection from drafts and dust as well. Consider using both exterior and interior covers for complete protection.
Cost Considerations for Winter AC Protection
Protecting your window air conditioner is a smart investment compared to the cost of replacement. A quality commercial cover typically costs between $15-60, while a new window unit can range from $150-700 depending on size and features.
DIY solutions can reduce costs further, with materials often available for under $30. Even premium protection methods like custom covers or removal services are significantly less expensive than replacing a unit damaged by winter weather.
| Protection Method | Estimated Cost | Lifespan |
|---|---|---|
| Standard Commercial Cover | $15-40 | 2-3 years |
| Premium Commercial Cover | $40-60 | 3-5+ years |
| DIY Tarp Solution | $10-20 | 1-2 years |
| Professional Removal & Storage | $100-150 per season | N/A (service) |
| Insulation Materials | $15-30 | 1-2 years |
When budgeting for winter protection, consider the climate severity in your region. Harsher winter conditions warrant investing in higher-quality protection methods. For expensive or newer units, premium protection options offer greater assurance against damage.