Years ago I used to install Friedrich air conditioners
which were built in two parts. A bunch of competitors
had this option, too.
First was the sleeve, which weighed just a couple of pounds.
This was easy to fasten into place - particularly helpful
if placing the unit at the top of the window.
Once this was properly fastened, then I'd simply pick up
the main part of the unit and slide it in.
Anyway.. while I can still find similar arrangements
for through-the-wall air conditioners, I haven't located
any that are built for windows.
- The window design is a bit more efficient energy wise
as the outdoor "cooling air" that flows over the compressor
comes in through the sides of the unit and out the back.
The "through-the-wall" ones use just the back grill for
both the incoming and outgoing air (there's a baffle
in between) so it doesn't flow as easily and costs
a performance penalty.
Thanks muchly for any pointers
Knowledge may be power, but communications is the key
[to foil spammers, my address has been double rot-13 encoded]