Will SWERV Fit My Window? Window ERV Fit Guide
SWERV fits double-hung, single-hung and horizontal sliding windows that are at least 23 inches wide and open at least 6 inches. It does not fit casement, crank-out, awning or tilt-and-turn windows. Here is how to check yours in two minutes with a tape measure.
Window types at a glance
| Window type | Does SWERV fit? | Notes |
|---|---|---|
| Double-hung (both sashes slide up and down) | Yes | The most common fit. On most double-hung windows nothing sticks out outside, and you usually do not need to remove the screen. |
| Single-hung (bottom sash slides up) | Yes | Same as double-hung. Some single-hung windows need the screen removed. |
| Horizontal slider (sash slides left and right) | Yes | Mount SWERV vertically or horizontally. Blinds may not close as fully because they have to clear the unit. |
| Casement or crank-out | No | The sash swings out, so there is nothing to close down onto the unit. |
| Awning or hopper | No | Same reason as casement. |
| Tilt-and-turn (common in Passive House and European builds) | No | We know this is a real gap and would rather say so plainly. |
How to measure
- Width of the opening: measure the inside of the window frame where the sash slides. You need at least 23 inches. The unit is about 23 inches wide, and insulated foam panels fill the rest.
- How far it opens: open the window and measure the gap. You need at least 6 inches.
- Sill depth: SWERV needs about 2 inches of sill inside the window. It extends about 6 inches into the room.
- For a horizontal slider mounted vertically: the opening needs to be at least 23 inches tall.
Wider than 48 inches?
Still fine. There is no upper limit on width. The kit includes enough foam for windows up to 48 inches, and for anything wider we include extra foam at no charge. Mention your measurements in your order notes or message us.
What installation looks like
SWERV weighs 19 lb and needs no bracket, drilling or screws. Set it on the sill, trim the foam side blocks to length, and close the window down onto it. Most installs take 10 to 15 minutes for one person. The installation guide walks through each step. Because nothing is permanent, it works for renters and comes with you when you move.
Common questions
Can SWERV share a window with an air conditioner?
We do not recommend it. Two units in one window are hard to seal well and can make the AC less secure. A separate window works much better.
Is it secure?
The window closes down onto the unit, the same way a window AC sits. For extra security and a tighter seal, add SWERV window locks.
Still not sure?
Send a photo of your window and rough measurements through our contact page. We answer every one, usually the same day.
More answers in the SWERV FAQ, or see the SWERV V3 window ERV.