Since I live in really hot weather and very low humidity, I thought I'd post these ideas. Someone might find them useful. Oh, and if anyone else has some thoughts on how to keep coops cool, please post them here (they might help me! ^_^) These ideas were taken from a MSN.com article for keeping houses cooler for less money. 1. Open windows and use fans. Even mild air movement of 1 mph can make you feel three or four degrees cooler. Make sure your fan is turned for summer -- you should feel the air blown downward. 2. Consider installing an evaporative cooler ("swamp cooler") if appropriate for your climate. A well-placed and -sized whole-house fan pulls air through open windows on the bottom floors and exhausts it through the roof, lowering the inside temperature and reducing energy use by as much as third compared with an air conditioner. Cost is between $150 and $400. Extremely useful for dry areas. 3. Put in white shades/drapes/blinds to reflect heat away from the coop. Close curtains on south- and west-facing windows during the day. Perhaps cover windows with cheesecloth to still let in the light while reflecting heat. 4. Tinting windows against sunlight, like the idea in 3, will help to reflect heat out of your coop while still letting the light in. 5. Grown on trellises, vines such as ivy or grapevines can shade windows or the whole side of a coop. 6. Avoid landscaping with lots of unshaded rock, cement, or asphalt on the south or west sides because it increases the temperature around the coop and radiates heat into it after the sun has set. 7. Deciduous trees planted on the south and west sides will keep the air cooler in the summer. Just three trees, properly placed around a yard, can keep daytime air temperatures 3 to 6 degrees cooler. 8. Replace incandescent bulbs with compact fluorescents; they produce the same light but use a fifth the energy and heat. 9. Caulking and weatherstripping will keep cool air in during the summer. 10. Using light-colored shingles on a new roof can cut the amount of heat the coop absorbs. Repainting in a light color, especially south- and west-facing exterior areas, helps as well.