yes but if the op doesn't have an ac already, could be renting, which severely limits what kind of ac you can get.

But yes split units are of course far better efficiency. I been eyeing up next years upgrade to an external unit with heat pump and 5 internal units for the 3 bedrooms, lounge and kitchen. But given how expensive the unit is i don't even know how much would it cost to install something like that. Lucky for me the house is arranged so that only one of the internal units would be a complete pain in the arse to install. So hopefully its something I can afford to do for next summer... fingers crossed

Depending on your room size and budget, i would recommend at leasr 12k btu and always try to get one with a heat pump so you can use it in winter too.

sticking the output hose out of the window is good enough to get started but even using the fabric window kit is good enough to be more comfortable.

For reference i used a 14k btu in a 25-30ish m2 room and it was more than enough in +38 heat. If you start to cool it down early in the day and close curtains you can prevent alot of heat later in the day.