Portable air conditioner

[Brokit]

Last summer when the temperature was in the 30s I decided to get an air conditioner for my unbearable attic bedroom. There were none left to be had.
So I'm feeling smug that in march when it was snowing I bought one .It's gone up massively in price since as well..
It works quite well with the hose stuck out of the window but I was wondering if it's worth getting one of those window kits? Does anyone have one?

I made a window kit out of layers of thick cardboard (with a hole for the vent), and tape it up around the window when its on. It definitely helps!

That sounds worth a try before buying one. I have some bubble wrap that might do the job.