Whynter's recommended casement venting solution
Venting your Whynter portable AC
through a casement or awning window
Your window is hinged, so the sliding window kit in the box won't work. You need a custom solution, and you've come to the right place.
Compatible with every Whynter portable A/C
Here's what you're getting
- Cut to your exact window. You measure once, we CNC-cut a ¼″ crystal-clear acrylic insert to fit your opening precisely.
- Seals airtight around your Whynter's hose. Hot exhaust goes out, cool air stays in — no gaps, no duct tape, no cardboard.
- In for the summer, out in the fall. Sits in the open window frame — nothing drilled, nothing glued. Reuse it every season.
★★★★★
“I am shocked at how perfectly it fits into the window screen space. It couldn't be any more snug.”
Daniel D. — Verified buyerJune 15, 2026
★★★★★
“Well done! Amazing product solving a clear challenge with a really simple buying journey, too. Martinson Manufacturing, you guys nailed it.”
Mark O. — Verified buyerMay 17, 2026
★★★★★
“From the ordering experience to receiving the product, we were 100% satisfied. The ordering process was simple. The window piece came in safely packaged and installation was less than 10 minutes. We are so happy with it! Wish we ordered sooner.”
Meghann H. — Verified buyerJune 10, 2026
Step 1
Find your hose type/size
Pick your model and we'll tell you the hose type/size.
[ BACK-OF-UNIT IMAGE ]
AC style
—
Hose diameter
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Take note of your AC style — you'll need it later.
Step 2
Which style window will you be venting out of?
Casement Window
Side-hinged windows that swing open and are difficult to seal properly with standard kits. This custom insert is cut to your exact opening, creating a tight seal so hot air vents outside efficiently instead of leaking back in.
Build My Casement Insert
Awning / Basement Window
Top- or bottom-hinged windows that leave awkward gaps most standard kits can't handle. This insert is built to fit your exact opening, allowing your AC to vent cleanly outside without leaks or patchwork fixes.
Build My Awning InsertNot sure which you have? Call 262-340-1418 or send us a photo — we'll tell you in a minute.
4.9/52,786 verified reviews
15,000+windows vented
2 daysmade & shipped
Guaranteefree remakes
Perfect Fit Guarantee
If your window insert doesn't fit your window perfectly, we'll remake it for you free of charge.
Seriously.
Even if the measuring mistake was yours.
Just email us at info@martinsonmanufacturinm.com and let us know what needs adjusting, “make the width 1/4 inch wider,” “shorten the height,” whatever you need. We'll cut a new one and ship it out the next business day.
We're not in the business of leaving you stuck with something that doesn't work.
- Step-by-step measuring video guides you
- Universal hose design fits every AC unit
- Every order reviewed before fabrication
- If it does not fit we remake it for free
Trusted by thousands of homeowners who needed a real casement window solution.
