Finally bit the bullet and bought myself a portable AC unit (Black & Decker 10,000 BTU). Not the most expensive item on the market, but not the cheapest either. Arrived today. After struggling to get the 30kg box up the stairs it was very easy to set up. Just a pity the pipe doesn't reach my top window (about 1 foot too short to be able to use) so I popped it out the main window (casement). As a reviewer on the rainforest site said, it has a refrigerator whine. Had it running for a couple of hours today and within 1/2 hour my room (south facing) dropped from 26 to 20c. Much more comfortable. Just need to find a window kit for it as it doesn't come with one and see if there's a way to extend the pipe to the top window.