How to seal window gaps around an air conditioner against insects
Window air conditioners often leave wide gaps and openings that allow flying insects like horseflies and wasps to enter the room. Makeshifts like duct-taped fabric unstick over time, leaving tenants struggling to properly insulate irregular windows like jalousies or units that do not fit standard openings.
What people tried
Every workaround mentioned in the threads below. We haven’t tested any of them — and nobody here is claiming they worked.
- 1Using duct tape to attach a pillowcase or cardboard to the glass and wall
- 2Using gaffer tape
- 3Using plumber tape or zip system tape
- 4Rolling and folding cardboard to expand and fit in the gap
- 5Using Saran wrap on each side and filling the gap with expanding foam
- 6Installing commercial foam side panels or screen door mesh panels
In their words
Unedited, most upvoted first, each linked to the thread it came from.
“Does anyone have advice on how I can insulate my jalousie windows while I run my AC?”source ↗
“I’m renting and wasn’t allowed to get a window unit.”source ↗
“I have an AC unit that sits inside a much wider window, and to keep out flying insects I've duct taped a pillow case onto the glass and surrounding wall. However, every once in a while it'll unstick and horseflies/wasps will enter my room.”source ↗