DIY AC. This is really easy to make and would help keep the room a lot cooler in the early and late parts of the year. You don't have to have bagged ice in the center either, ice packs or a frozen gallon of water work fine.
5 Gallon Bucket Swamp Cooler DIY Project - Cooling your tent or van. The basic idea for the bucket cooler is just a smaller version of Yellowdog's cooler made from a rubbermade garbage can. An evaporative cooler will reduce the temperature by 20 to 30 degrees. All the ideas that people came up with on this thread are a perfect example of radical self relience! (Bravo!!!)
5 Gallon Bucket Creations for Off-Grid Camping or Emergencies #Preppers - YouTube Gloryma Nazario shared a video
Homemade 5 gallon bucket Air Conditioner: Small fan set on top of lid, 1 gallon milk jug of frozen water inside the bucket. Air output varies between 40-45 degrees F. It can also be made with a styrofoam cooler instead of the bucket.