The Evening Breeze Canopi is great for low-powered bedroom air conditioning, but the actual rig is seriously pricey. If you're looking for something a little more within budget, the Kuchofuku Air-Conditioned Bed should keep you cool during sleep, while offering more attractive overall costs.
Used for eight hours a day, it claims to add a mere 24 cents to your monthly utility expenses. Ridiculous? Not really, since I doubt it's really an air-conditioner anyway. From what I can tell, it simply pulls air from behind your head and circulates it right inside the slim mattress using built-in fans. While it won't have you chilling like a naked caveman in the middle of winter, it should make for a cooler sensation on your back while you're lying in bed.
The Kuchofuku Air-Conditioned Bed is not actually a bed, either. Instead, it's a 36 x 79 inch air cushion you lay over the mattress. To begin its "air-conditioning" function, you need to fire up the two fans installed at the bottom end of the sleeping mat, which can be set to run at three different speeds. Don't worry, the fans operate quietly with no rousing movement and can be programmed with an hourly timer.
We're not sure how well this will cool you on a really humid summer night. But if you don't want to spend a bundle on real air-conditioning, it should only hurt a little to try. Plus, its pretty light at 5.3 lbs and comes with its own storage bag, so you can haul it to a cooler area of the house in case your bedroom is exhaustingly warm. You can order it as a Japanese import for $498.