I know they cost money, but I’ve got 2 portable air conditioners we drag out a few days a year that are still working. I actually bought two 15 years ago, both still work well today, although I did swap one (12000btu with twin pipes) with a 9000btu single pipe one to help a mate out (the 900btu one wouldnt overcome severe heat in a loft conversion bedroom, but the 12000 btu ones did easily).
I paid £329 each all that time ago and they are much more expensive now (£349). I can’t believe how they still work since they spend most of their time in the shed or garage, but they do! I did strip the covers and clean all the years of fluff covering the condenser/heat exchanger rads this year which made a difference.
The larger unit took our main bedroom from 31 to 21 in two hours..
yes it’s noisy, like a fan on full speed, but everyone in the house prefers that to sweating to death....
I’ve got two split air conditioners that are 12 years old sat in the garage never installed (cheap offer in a Spanish supermarket that we brought back with us) the idea being I’d replace the portable ones when they died, but they never did..