How have you managed the window vent for a portable air conditioner?

[dudsville]

We have a portable air con with the hose that vents out of the window. I would like to make the fitting better, more airtight, but obviously not permanent as we only need it a handful of times a year, and it has to be removed when we're out and need to lock up. Ours came with the fabric thing, but the zip didn't hold and the thing didn't fit the window well. I've seen that there are perspex options and I'm curious about that, but also any solutions really. If you have this set up and have a solution that works for you I would be grateful for the recommendation.

We bought a piece of Perspex the size of our widow and DH cut a hole in it for the tube. The tube gets hot though so that’s covered up with a blanket so the heat doesn’t radiate.

I bought the velcro zip kit from Amazon that fit my window, but as it's an attic I plan to leave it attached all summer and don't have to faff with it.

If I had to open and close it every time I'd honestly consider just shoving a pillow in the gap or something.

The fabric ones left my window really mucky with bits of Velcro, then the adhesive after we got the Velcro off. DS bought the Perspex cut to size, complete with hole. It works brilliantly. Doesn’t look like a doss house from outside, either!

Thanks @Glitterbiscuits and @PrizedPickledPopcorn , how do these perspex things fit? I'm keen to avoid velcro as per @LividSun 's experience. Does the perspex sit inside the opened window grooves in the frame?

You get it cut very neatly so it just snugs into the space. I’ll nip up and take a photo. It changes according to the shape of the window, so pick the best window for the job!

You could even use a piece of cardboard box cut to shape. But that might be more "doss house" than perspex!

Thank you so much, I really appreciate it!

And it would wilt in high humidity.

So sorry, he misled me. It was supposed to fit sufficiently tightly that it didn’t need taping. And it doesn’t. So no useful photo.

Apparently ‘doss house’ is his preferred look. We have a blind, a blackout curtain on an extending pole and a towel involved in the arrangement. 🙄

Luckily it’s 3rd storey so you can no longer see it from the street. It did look well dodgy when he had a cardboard sheet up against the window.

Our neighbours have done similar with a piece of plywood, which I presume has the benefit of also providing blackout, if that would be helpful. Piece of ply cut to the size of the window, with a hole cut in the middle for the hose to go through.

Drilled a hole in the wall and cap it in the winter

I honestly don't bother. Stick the hose out of the window and close as far as possible. Room gets cooler.

You're venting air from your room, that needs to be replaced from somewhere otherwise you're causing a vacuum and will die. The new air will come from outside or the rest of your house, in which case the rest of your house is pulling in air from outside and that will end up in your room.

This can be solved with a dual hose aircon like you get in America, or installed aircon where the compressor is on the outside of your house.

To answer your question, you can buy one of those thick polystyrene insulation blocks with the silver foil and them and cut it to fit the gap perfectly.

If you plan to use the unit on a regular basis, you should probably have a system like we have for our perspex(?) secondary glazing. You put magnetic secondary glazing tape around the perspex pane and the window frame to hold it on. We use suction bathroom grab handles to position and remove the panes. The tape is available in white, so it isn’t especially noticeable.

If you have sash windows, you can probably get a ready made panel on Amazon etc.

My dd bought a sheet of Perspex with a hole cut in it to fit her window. I cleaned the frame with sticker remover to remove the previous glue from the failed fabric thing and then vinegar to clean any grease off. The sheet came with sticky back Velcro, so I stuck the soft side to the window frame, stuck the rougher one to that and peeled off the backing and stuck the sheet to it. I pressed it very firmly but even then it didn't quite stick properly. I had to carefully pull it off whilst leaving the Velcro stuck on both sides and then was able to make sure the Velcro was firmly stuck down. This all sounds a bit tricky but it wasn't. You just need to make sure the frame is super clean of all grease and then the Velcro sticks firmly. It works really well and her room is now super chilly when the rest of the house is an oven.

@Madcats that glazing tape sounds like it would have been much easier to attach and to be able to remove the sheet as and when needed. The Velcro does like to stay attached to each other

I have sash windows which make it easy. Mine came with a plastic part that the hose clips on to.

As someone said above, you're never going to get the room totally air tight. I have cats that are allowed to freely come in/out of my bedroom so I don't shut the door completely. I put a curtain up in the doorway so the gap isn't as big. But tbh, the difference in the air con performance is negligible versus the door being properly closed.

We spent the first week faffing about with window kits - then abandoned it and just put the hose out the window and pull the window shut against the hose as tight as it will go.

Made zero difference to the efficacy of the aircon, or the smart meter.

We use a thick white towel and use parcel tape and tape it around the window. Works brilliant doesn't fall down, the parcel tape worked better than any other tape we tried. Just looks like I forgot to open the curtains, we looked into perspex but couldn't be bothered with the faff for the amount we use it, we also use the unit in different rooms though pending where we are so towel one size fits all!

Thanks everyone, I think the perspex thing is going to be the way to go - I'll look into that glazing tape @Madcats.

We don't have sash windows. I'm envious on my walks seeing how those that do have sash windows are fitting their aircon!

In future I think we'll have a second unit for downstairs, and I think between the 2 and a couple of fans to move the cool air about, we'll be fine, once I've sorted out the window situation!