Keystone - 450 Sq. Ft. 10,000 BTU Casement Window Air Conditioner - White

Does a great job cooling! Haven’t seen the electric bill yet, but it does say it is not an efficient cooling model, so I don’t have high hopes. But if you have vertically sliding windows, there are not a lot of options. To note: the description doesn’t point out some very important factors: this thing is limited on how tall your windows can be. It seems like the max height is smaller than typical window sizes. I had to cut a board down to deal with the gap — also, vertical sliding windows typically don’t have the material this requires for screwing in to the frame around the unit. You will also likely need a custom window slide lock, because if your child slides the window open, the unit is probably going down. See my custom slide lock in the images. All those fit issues solved with makeshift solutions and buying some extra window insulation strips, and this things does the trick! It is loud. Very loud. But I like that living in the city. Won’t be hearing any frogs singing with this beast on, though, if you want that countryside soundtrack.

Perfect for my office that only has slider window! Ice cold!’

I wouldn’t know how the unit performs because I received the unit damaged upon delivery! The packing is very poor and does not survive the transport! I refused delivery and UPS returned the unit. Unfortunately I’m still awaiting a refund (almost 1 month) for something out of my control! Unfortunately BestBuy doesn’t stock this item in the store and you have to rely on shipment from the vendor! They should pack an 88 pound item with better materials and not just thin cardboard and styrofoam! This is the 2nd unit I’ve ordered and both had arrived damaged! I was told to wait until the return was credited and then place another order to receive the same sale price but now they are out of stock! So is everyone else who carries this unit and this is the only size A/C I can use…so I guess I will be without air conditioning for the hot summer even though I tried to buy this way in advance of the heat! Very upsetting…very poor customer service!

We had an air conditioner, but it was designed for vertically opening windows, so while I had constructed a special frame for it to fit the window, it was really heavy and hard to get into the window and never felt very secure. We decided to get a unit meant for sliding windows and went with this. It comes with a mounting kit, which is great, though I do wish the frame was a little more flush with the edges of the window frame. Additional weatherproofing is necessary, but I already had those materials, so it was no big deal. The unit itself works great, is not as loud as I thought it would be, and is doing a great job of keeping our kitchen, dining room, and living room cool. We bought a second for our bedroom and have been luxuriating in having a super cool room when going to bed on warmer nights.

Needed an AC unit to fit an attractive, yet impractical horizontally opening window. The installation required a little adaptation, as the installation needed about another two feet vertically to closer of the window. Not a huge deal, except they are no out of the box solutions. I filled the gap with one inch insulating form project board, painted to camouflage it. It cools a relatively small room nicely, and that what we needed. Mentions of minor handling imperfections (dents and bent stuff) in other reviews are real, but not terribly blatant on the unit i received.