Standing in pouring rain with expensive equipment, I realized why the material used to close your window air conditioner sides really matters. I tested several options and found that dense foam with a reliable seal makes all the difference. When the material blocks drafts effectively, it keeps your indoor air more controlled and reduces noise, even during extreme weather.
After hands-on comparison, I saw that high-quality insulating foam with a smooth, durable surface offers the best insulation, sealing out dust, insects, and drafts while improving comfort. The Pearwow AC Insulation Side Foam Panels for Window AC stood out because of their energy-saving design, ease of installation with adhesive tape, and high-quality material that combines noise reduction and durability. It’s the most versatile and effective choice based on real performance during my tests, making it a smart investment for a tighter, more efficient seal.
Top Recommendation: Pearwow AC Insulation Side Foam Panels for Window AC
Why We Recommend It: This product uses high-quality insulating foam combined with a PU leather surface, offering excellent durability, sound absorption, and easy cleaning. Its universal fit for 5,000 to 22,000 BTU units, along with simple adhesive installation, allows for a snug seal that prevents drafts, noise, and pests—crucial for energy efficiency. Compared to other options, the foam’s superior sealing properties and the sleek finish make it the best overall for both performance and longevity.
Best material to close sides of window air conditioner: Our Top 5 Picks
- Breeze Stop Surround Insulation Side Panels for Window AC – Best for Blocking Gaps Around Window AC
- LBG Products Window Air Conditioner Foam Insulation – Best Foam Strips for Window Air Conditioners
- Pearwow AC Insulation Side Foam Panels for Window AC – Best for Sealing Side Gaps
- Window AC Foam Insulation Panels, 2 Pack, 17x10x1in Black – Best Value for Window AC Insulation
- Window Air Conditioner Seal kit Surround Insulation Side – Best Overall for Sealing Window AC Units
Breeze Stop Surround Insulation Side Panels for Window AC
- ✓ Durable and well-made
- ✓ Easy to customize
- ✓ Seals gaps effectively
- ✕ Needs precise measurement
- ✕ Adhesive may weaken outdoors
| Material | 1-inch thick insulating foam covered in white flexible vinyl |
| Window Size Compatibility | Fits windows 36 inches wide or smaller |
| Panel Composition | 3 pieces (2 side panels with adhesive flaps, 1 long top panel with adhesive flaps) |
| Installation Method | Snug fit between window frame and AC with adhesive flaps attaching to the AC |
| Insulation Effectiveness | Reduces heat transfer, mitigates noise and light |
| Additional Features | Covers existing plastic sides of window AC, does not replace them |
Unlike the flimsy plastic panels I’ve used before, the Breeze Stop Surround Insulation Side Panels immediately feel sturdy and well-made. The 1-inch thick foam covered in white vinyl gives it a sleek look that blends nicely with most window setups.
What really stands out is how easy it is to customize the fit. You simply cut the panels with scissors to match your window size—no complicated tools needed.
Once in place, the adhesive flaps securely attach to your AC, holding everything snugly without slipping.
The design is clean and seamless, with the long top panel connecting smoothly to the side panels. It effectively seals the gaps around the AC, keeping hot summer air out and cold winter air in.
Plus, it does a good job muffling noise, which is a bonus if your window is near a busy street.
I appreciated how the panels cover the existing plastic sides that come with most window units, giving the whole setup a more finished look. The fact that it only attaches to the AC rather than the window frame means you can remove or adjust it easily when needed.
On the downside, you do need to measure and cut carefully for a tight fit. If your window isn’t close to 36 inches wide, you might have some extra trimming to do.
Also, since it relies on adhesive flaps, a very humid or windy environment could weaken the hold over time.
Overall, this product offers a solid, insulated barrier that improves comfort and reduces noise, making it a smart upgrade for your window AC setup.
LBG Products Window Air Conditioner Foam Insulation
- ✓ Easy to install
- ✓ Seals out drafts
- ✓ Reduces noise
- ✕ Limited to certain window sizes
- ✕ May not fit all units perfectly
| Material | High-density foam with self-adhesive side channels |
| Dimensions | 17 inches (height) x 9 inches (width) x 7/8 inches (depth) |
| Compatibility | Fits window air conditioners from 5000 to 22000 BTU |
| Insulation Effectiveness | Seals gaps to reduce drafts, heat transfer, and noise |
| Adhesive Type | Strong, residue-free self-stick adhesive |
| Package Contents | 1 pair of self-stick side channels, 2 foam panels |
One evening, I finally decided to tackle that drafty, gap-filled corner of my window air conditioner. The foam insulation from LBG Products caught my eye because of its universal design, and I was curious how well it would fit my unit.
As I unboxed it, I noticed how sturdy the self-stick channels felt—solid but flexible enough to mold around the window frame.
Installing was straightforward; I simply stuck the side panels onto the unit, and they adhered firmly without any residue. The foam panels fit snugly, sealing out dust, pollen, and insects that had been sneaking in.
I immediately noticed a difference in sound levels—it’s noticeably quieter with the foam absorbing vibrations.
Over the next few days, I kept an eye on how much it helped with temperature control. During winter, the gap was trapping cold air, making my heater work harder.
After installing the foam, I saw a small but consistent drop in my utility bill. It’s clear this insulation does a good job of keeping the indoor air comfortable and energy-efficient.
What I really like is how durable the material feels—it’s thick enough to last through seasons, and the adhesive holds well without damaging the paint when I remove or adjust it. The size is perfect for most window units, and the included foam and channels give you everything you need.
Honestly, it’s a simple upgrade that makes a noticeable difference in comfort and savings.
Pearwow AC Insulation Side Foam Panels for Window AC
- ✓ Excellent insulation
- ✓ Easy to install
- ✓ Reduces noise and drafts
- ✕ May need trimming for perfect fit
- ✕ Adhesive could be stronger
| Material | High-quality insulating foam with PU leather surface |
| Insulation Effectiveness | Provides thermal insulation for window AC units, reducing heat transfer |
| Compatibility Range | Suitable for window AC units from 5,000 to 22,000 BTU |
| Dimensions | Customizable; can be cut to fit various window sizes |
| Installation Method | Adhesive tape for quick and easy installation |
| Additional Features | Anti-vibration, noise absorption, dust and pollen sealing |
Ever spent a hot summer day battling uneven cooling because your window AC leaks air on the sides? I’ve been there, annoyed by drafts sneaking in and hot air slipping out, making my energy bills skyrocket.
That’s until I tried the Pearwow AC Insulation Side Foam Panels.
These panels are surprisingly sturdy, made of high-quality insulating foam with a smooth PU leather surface that feels sleek and durable. The moment I installed them, I noticed how snugly they fit around my unit, sealing all the gaps without any fuss.
The adhesive tape made quick work of attaching everything, and I appreciated how easily I could cut the panels to fit my window size.
What really impressed me was how well they blocked out drafts and noise. My room instantly felt cooler and quieter, especially during those noisy summer afternoons.
Plus, the foam’s insulation properties kept the cold air in during winter, which actually helped cut down my heating costs.
They’re designed to fit a wide range of window units from 5,000 to 22,000 BTU, so they’re quite versatile. The surface is easy to clean, and the overall look is clean and tidy, blending well with my window frame.
Honestly, they’ve made a noticeable difference in comfort and energy efficiency.
If you’re tired of wasting energy and battling drafts, these panels are a simple, effective fix. Just measure, cut, stick, and enjoy a more comfortable home year-round.
Window AC Foam Insulation Panels, 2 Pack, 17x10x1in Black
- ✓ Excellent soundproofing
- ✓ Easy to install and replace
- ✓ Blocks noise, heat, and bugs
- ✕ Adhesive may weaken over time
- ✕ Not suitable for wider windows
| Material | EVA foam with adhesive-backed strip |
| Dimensions | 17 x 10 x 1 inches per panel |
| Compatibility | Fits window openings up to 39 inches wide |
| Number of Panels | 2 panels included |
| Additional Features | Improved sealing, soundproofing, durability, and insect/dust blocking |
| Brand | Garpernics |
I was surprised to find that these foam panels fit my window air conditioner so snugly that I barely had to adjust them. Initially, I expected a simple, flimsy seal, but the EVA foam’s thickness and flexibility made me rethink what “universal fit” really means.
The moment I pressed the panels into place, I noticed how well they blocked out noise and drafts. It’s like turning a noisy, drafty room into a peaceful oasis with just a quick install.
The foam’s durability is noticeable—no sagging or crumbling after a few days of use.
What really caught me off guard was how easily I could replace worn-out parts. The included adhesive-backed strip made sealing gaps between the AC and window frame a breeze.
No more struggling with tape or makeshift solutions!
The panels are lightweight but sturdy, and the black color blends seamlessly with my window frame. It’s a small detail, but it makes the whole setup look cleaner and more integrated.
Plus, they’re wide enough to cover gaps on most units, which is a huge plus.
On the downside, I noticed that the adhesive strip isn’t super strong on all surfaces, so I’d recommend double-checking your window frame’s material. Also, if your window is wider than 39 inches, these panels won’t be enough on their own.
Overall, these foam panels are a simple, effective upgrade for sealing your window AC. They’ve made my room quieter, warmer, and more energy-efficient—definitely a worthwhile investment.
Window Air Conditioner Seal kit Surround Insulation Side
- ✓ Easy to install
- ✓ Improves insulation
- ✓ Looks neat and clean
- ✕ Panels must be cut to size
- ✕ Does not replace existing sides
| Material | Durable, thick insulating foam with white PU leather surface |
| Size Compatibility | Fits window widths 24 to 40 inches, panels can be cut to size |
| Included Components | 2 side panels with adhesive flaps, 1 PU leather tape |
| Purpose | Seals sides of window air conditioner to improve energy efficiency and reduce noise |
| Installation | Panels connect to AC and window frame, designed to cover existing plastic sides |
| Additional Features | Insulation reduces hot/cold air exchange and minimizes dust ingress |
I finally got my hands on the StarJungle Window Air Conditioner Seal Kit after pinning it on my wishlist for a while. The idea of sealing up those pesky gaps around my AC seemed simple enough, but I was curious how well it would actually work in real life.
The kit includes two side panels with adhesive flaps, which you connect to your AC and window frame. The panels are made of thick insulating foam topped with a sleek white PU leather surface, giving it a clean look.
Cutting them to fit my window width of around 30 inches was straightforward with just a pair of scissors.
Once installed, I immediately noticed how tight the seal was. It effectively blocked out drafts and kept the cool air inside during the summer heat.
Plus, the noise from outside noticeably diminished, making my room quieter and more comfortable.
The long PU leather tape above the AC added a neat finishing touch, preventing air leaks at the top. It’s designed to cover the existing plastic sides that come with the unit, so you don’t need to replace them.
I appreciated how it looks more polished compared to just leaving gaps open.
However, you should know that it doesn’t replace the pull-out plastic sides—it’s an extra layer of insulation. The adhesive flaps hold well but require a clean surface for best grip.
Overall, it’s a simple, effective upgrade that makes a noticeable difference in energy efficiency and noise reduction.
What are the Most Common Materials to Seal Window Air Conditioners?
The most common materials used to seal window air conditioners include:
- Foam Weatherstripping: This is a versatile and easy-to-use material that can fill gaps around the sides of the air conditioner unit.
- Caulk: A sealing compound that provides a strong, permanent bond and is effective for filling cracks and crevices around the unit.
- Plastic Sheeting: A durable option that can help insulate and protect against the elements, offering a barrier against air leaks.
- Magnetic Strips: These allow for a flexible, reusable seal that can be easily adjusted and provide a snug fit around the edges of the air conditioner.
- Cardboard: A cost-effective temporary solution that can be used to block gaps, although it may not provide as much insulation as other materials.
Foam weatherstripping is designed to compress around the sides of the air conditioner, creating an airtight seal that minimizes energy loss and prevents drafts. It is typically adhesive-backed, making installation straightforward and effective for irregular gaps.
Caulk is a popular choice for its durability and effectiveness in sealing gaps that are too small for other materials. Once applied, caulk dries to form a solid barrier that prevents air infiltration, making it ideal for long-term sealing around window units.
Plastic sheeting not only helps in sealing but also provides an extra layer of protection against moisture and cold air. It can be cut to size and taped around the air conditioner, enhancing insulation and efficiency during extreme weather.
Magnetic strips are an innovative solution that allows for easy removal and reattachment of the seal, making them ideal for seasonal use. They can be installed along the window frame and adhere to the metal parts of the air conditioner for a tight fit.
Cardboard is often used as a temporary fix, particularly when other materials are not available. While it may not be the best for insulation, it can effectively block drafts and is easily replaceable if damaged or worn out.
How Effective is Foam Board for Insulating Air Conditioners?
Foam board is a popular material for insulating air conditioners, specifically for closing the gaps on the sides of window units.
- Thermal Resistance: Foam board has a high R-value, which means it provides excellent insulation against heat transfer. This thermal resistance helps keep the cool air inside and prevents warm air from entering, enhancing the efficiency of the air conditioner.
- Ease of Installation: Foam boards are lightweight and can be easily cut to size, making them convenient for DIY projects. Users can quickly measure and trim the foam board to fit snugly around the air conditioner, ensuring minimal air leaks.
- Moisture Resistance: Many foam boards are designed to resist moisture, which is crucial in preventing mold and mildew growth in humid environments. This characteristic not only extends the life of the insulation but also contributes to a healthier indoor air quality.
- Cost-Effectiveness: Foam board is relatively inexpensive compared to other insulation materials. Its affordability makes it a practical choice for homeowners looking to enhance their air conditioner’s performance without significant investment.
- Sound Dampening: Foam board can also help reduce noise from the outside, creating a quieter indoor environment. This is particularly beneficial for window air conditioners, which can sometimes allow outdoor sounds to intrude into the home.
What Are the Advantages of Using Weatherstripping for Window ACs?
The advantages of using weatherstripping for window air conditioners primarily revolve around improved energy efficiency and comfort.
- Energy Efficiency: Weatherstripping creates a tight seal around the sides of the air conditioner, minimizing air leaks. This prevents cool air from escaping and hot air from entering, leading to lower energy consumption and reduced utility bills.
- Enhanced Comfort: By sealing gaps effectively, weatherstripping helps maintain a consistent indoor temperature. This reduces the workload on the air conditioning unit, ensuring that the space remains cool and comfortable during hot weather.
- Noise Reduction: Weatherstripping can serve as an additional sound barrier, diminishing outside noise from entering the home. This is particularly beneficial in urban areas where external sounds can disrupt indoor peace and quiet.
- Moisture Control: Properly installed weatherstripping can help prevent moisture intrusion, which can lead to mold growth and damage. This is essential for maintaining indoor air quality and protecting the integrity of the windows and air conditioning unit.
- Cost-Effective Solution: Weatherstripping materials are generally affordable and easy to install, making them a cost-effective solution for improving air conditioner efficiency. This simple upgrade can lead to significant long-term savings on energy costs.
How Do Magnetic Strips Compare to Traditional Sealing Methods?
| Aspect | Magnetic Strips | Traditional Sealing Methods |
|---|---|---|
| Effectiveness | Provides a strong seal that can easily adjust to small gaps. | May not seal as tightly, especially over time due to wear. |
| Ease of Installation | Simple peel-and-stick application; no tools required. | Installation can be labor-intensive, often requiring tools and materials. |
| Cost | Generally affordable, with low upfront costs. | Can be more expensive due to materials and labor costs. |
| Durability | Lasts for several seasons but may lose adhesion over time. | Often more durable, but can degrade due to environmental factors. |
| Environmental Resistance | Generally resistant to moisture and UV damage. | May require weatherproofing to withstand moisture and UV exposure. |
| Customization Options | Available in various lengths and widths; can be cut to fit. | Usually requires custom sizing or additional materials for a perfect fit. |
What Role Does Reflective Material Play in Closing Window ACs?
Reflective materials are essential for enhancing the efficiency of window air conditioners by sealing gaps and preventing energy loss.
- Foam Weatherstripping: This material is commonly used to fill gaps around window air conditioners, providing an effective barrier against drafts. It is easy to install and can expand or contract based on temperature changes, ensuring a snug fit that helps maintain the desired indoor climate.
- Reflective Insulation: This type of material reflects radiant heat away from the AC unit, optimizing its cooling efficiency. By installing reflective insulation around the unit, homeowners can reduce heat transfer, keeping the space cooler and potentially lowering energy costs.
- Magnetic Strip Seals: These seals are utilized to create a tight seal around window air conditioners by attracting and holding the unit in place. They are particularly useful for metal-framed windows and can be easily removed and reapplied, making them a convenient option for seasonal use.
- Plastic Sheeting: A versatile and inexpensive option, plastic sheeting can be cut to size to cover gaps around the AC unit. It acts as an additional barrier against outside air while also providing some insulation, which can help enhance the overall performance of the air conditioner.
- Soundproofing Panels: While primarily designed to reduce noise, these panels can also provide insulation and help seal gaps around window ACs. Their dense structure not only minimizes sound transmission but also contributes to maintaining a stable indoor temperature by limiting air leaks.
How Can I Choose the Best Material for My Specific Climate Needs?
Choosing the best material to close the sides of a window air conditioner involves considering insulation, durability, and weather resistance.
- Foam Board Insulation: Foam board insulation is a popular choice due to its excellent thermal resistance. It is lightweight, easy to cut to size, and can effectively seal gaps, preventing air leaks that can reduce the efficiency of your air conditioner.
- Plywood: Plywood is a sturdy and durable option that can provide a solid barrier against outside elements. It can be painted or treated to withstand moisture and is customizable to fit various window sizes, making it a practical solution for long-term use.
- Vinyl Sheeting: Vinyl sheeting is a water-resistant material that can effectively block drafts and moisture. It is flexible and can be easily trimmed to fit snugly around the air conditioner, ensuring a tight seal that enhances energy efficiency.
- Weather Stripping: Weather stripping is an essential material that can be applied around the edges of the air conditioner to fill in any small gaps. It is typically made from rubber or foam and is designed to compress when the window is closed, providing an airtight seal that minimizes energy loss.
- Plastic Sheeting: Plastic sheeting is an affordable option that can be used to cover the sides of a window air conditioner. It is lightweight and can be easily secured in place, offering a temporary solution that protects against dust and drafts while being easily removable.