I always post this, but just to help anyone on the fence, my almost 20 year old portable aircon units still work a treat, I wheel them out of the cupboard on the odd occasion, chuck some hoses out the window (takes all of 10 seconds), switch on and have a nice perfect 21 degrees in the room. They may have cost me £300 a pop in 2002 but talk about value for money now!
I know all the 'downsides' , but if you have a window in the room and feel the heat, you only live once, there is nothing like setting it to 19 degrees for an hour before bed and it's drawn all the heat out of the room/bedding, it's glorious..
The only advice I have is get the two pipe models (they can draw in cool air from outside in one, then exhaust hot air out the other), these have been better than a cheapo single pipe version we bought that seems very very inefficient in the hottest weather.
I did buy split aircons to install but sold those last year as the cost of installation etc is just such a massive degree higher that I couldn't be bothered.