ZENGSHI LIFE MUSEUM Window Air Conditioner, 2 Pieces of Surface Insulation EVA Board, 17 inches * 10 inches, Simple installation design, Summer/Winter Heat and Draft Insulating,Two-Piece Panels Window Seal

My window AC has always whistled on blustery nights, a sure sign the stock accordion panels weren’t doing their job. Swapping those brittle inserts for a pair of EVA window AC side panels turned out to be a simple upgrade that tightened the seal, cleaned up the look, and kept out more of what I don’t want—drafts, dust, and bugs—without adding much complexity. These aren’t high-tech by any stretch; they’re essentially medium-density EVA foam sheets paired with an adhesive sealing strip. But used thoughtfully, they solve a very common problem with window units.

What this is—and what it isn’t

The kit includes two white EVA foam panels, each 17 by 10 inches, plus a 39 by 2-inch EVA sealing strip with adhesive. The idea is straightforward: cut the foam to fill the open gaps between your window AC chassis and the window frame, then use the sealing strip to close any remaining slivers and create a continuous air barrier.

This is a replacement for the plastic accordion “wings” that come with most window air conditioners, or a cover for those panels if they’ve cracked or gone dingy. It’s not rigid plastic, and it’s not weatherproof siding. Think of it as a tidy, cut-to-fit gasket system. If you’re expecting something structural or insulated like a rigid foam board, you’ll be disappointed. If you want an easy-to-fit, cleaner-looking seal that noticeably improves comfort, you’ll be happy.

Installation: easy, with a few tricks for a better seal

Setup took me about 20 minutes start to finish, with no tools beyond a measuring tape, marker, and a sharp pair of scissors. A utility knife also works, but the foam cuts cleanly with scissors.

Here’s the process that worked well for me:
- Dry fit: I measured the vertical opening height beside my AC, then marked and cut each 17 × 10 panel to height. The 10-inch dimension matched my unit’s height closely; check yours, because some taller units may need creative orientation or a small filler strip.
- Trim to width: With the height set, I measured the gap width from the AC side to the window frame, then trimmed the panel’s width accordingly so it sat snugly without bowing.
- Prep surfaces: I wiped down the window frame and the AC side with isopropyl alcohol to help the adhesive stick.
- Seal the edges: I placed the foam panels in the gaps, then ran the 2-inch-wide sealing strip along the panel’s perimeter where it met the frame and AC case. The strip is flexible enough to bend around corners and compress into tiny irregularities.
- Finish and press: A firm press along all adhesive points helps the bond. I added a short overlap at the panel seams to reinforce the seal.

The whole thing is forgiving: cut a hair large and compress the foam, or cut a hair small and bridge with the sealing strip. I liked that I could make the panels exactly the size I needed rather than wrestle with brittle plastic or tape-heavy DIY solutions.

Fit and compatibility

The manufacturer calls out compatibility with units rated from 5,000 to 22,000 BTU. That’s a wide range, and the reality depends more on your actual side gaps than on BTU. For small and mid-size units, the 17-inch length gives plenty of material to cover a typical side gap after trimming. For larger chassis or unusually tall openings, you may need to orient the panel differently or join offcuts to span the full height.

On my mid-size unit, each panel covered one side perfectly. The white color blends with most window sashes and vinyl frames, and it looks cleaner than the grimy plastic accordions my AC shipped with.

Performance: comfort bump, quieter nights, fewer pests

Once installed, I noticed three practical improvements:

• Draft control: The whistling stopped, and the faint cool draft around the unit disappeared. It’s a small improvement you feel most near the AC and on windy days, but it adds up to a more consistent room temperature.
• Noise and vibration: EVA foam dampens a bit of fan hum and chassis rattle. Don’t expect dramatic soundproofing, but it takes the edge off.
• Bug and dust exclusion: The better seal kept out gnats and dust that used to sneak in through the gaps. If you’re in a pollen-heavy area or a building with frequent fruit flies, this helps.

On the energy side, any seal improvement reduces heat transfer and infiltration, but it’s incremental. You’re not going to slash your bill from this alone; paired with a properly leveled unit, well-sealed sash, and insulated curtains, it’s one of several useful steps.

Durability and upkeep

EVA foam is resilient but not indestructible. After a few weeks, the panels remained firmly in place and held their shape. Long term, a few considerations:

• Sun exposure: Direct UV can discolor white foam and slowly degrade it; if your AC sits in harsh sun, expect cosmetic aging over time.
• Adhesive longevity: The sealing strip adhered well on clean wood and metal, but oils, dust, or textured paint can reduce grip. If you move the AC seasonally, be prepared to replace sections of the strip or clean off residual adhesive.
• Cleaning: A damp cloth wipes off dust. Avoid solvents that could soften the foam.

If you remove your AC in winter, the panels store flat without warping. I recommend saving any offcuts; they’re handy for patching small gaps the next season.

Where it falls short

• Material perception: There’s no getting around it—this is foam and an adhesive strip. If you expected rigid panels or integrated hardware, you’ll think it feels basic.
• Large gaps or uneven frames: For very wide openings or highly irregular frames, you may need additional backing or shims. The foam compresses nicely, but it can’t span a big void without support.
• Aesthetic limitations: While cleaner than old accordions, the foam still looks like foam. It’s neat, but not seamless millwork. If you’re after a permanent, built-in appearance, a custom rigid insert will look sharper.

Tips for the best result

• Measure twice, cut once—and keep cuts square so the panel seats snugly.
• Slightly oversize your cut and compress the foam for a tighter fit.
• Clean all mating surfaces with alcohol before applying the sealing strip.
• Use the sealing strip to bridge seams and corners; overlap by at least half an inch for strength.
• If your frame is very uneven, backfill voids with narrow offcuts before sealing.
• For a more finished look, run a thin bead of removable caulk along the outer edge. It peels off cleanly at season’s end and improves airtightness.

Alternatives and use cases

If you’re replacing shattered accordion panels, this is an easy upgrade. If your unit never had side panels and you’ve been improvising with cardboard and packing tape, this looks neater, seals better, and resists moisture. For extreme climates or a semi-permanent installation, consider combining these foam panels with a thin rigid PVC or corrugated plastic backer to add structure and durability.

The bottom line

These EVA window AC side panels are a modest, practical fix for a common weak point in window installations. They trim cleanly, install quickly, and meaningfully improve the seal around an AC. You’ll feel less draft, see fewer bugs, and hear slightly less noise. The materials are simple, and the result depends on careful measuring and surface prep. They’re not a miracle cure for energy loss, and they don’t replace the need for a well-installed unit and a tight sash. But as a low-fuss solution, they work.

Recommendation: I recommend these panels if you want an easy, customizable way to replace or upgrade your AC’s side seals without tools or hardware. They’re particularly good for renters, for older units with failing accordions, and for anyone who values a cleaner look and a tighter seal. If you need a rigid, permanent solution for large or irregular gaps—or you expect high-end materials—you’ll want a different approach. For most typical window units, though, this simple foam-and-adhesive kit delivers reliable, noticeable improvements where it matters.