Since summer is now over, you are probably thinking about heaters rather than air conditioners, but I don't think you should skip learning about the DEVap air conditioner. A revolutionary cooling system, it will reduce your energy use by 90 percent.
Developed by the National Renewable Energy Laboratory, the DEVap air conditioner "avoids the refrigeration process powered by a compressor and instead uses high-efficiency pumps and fans, in addition to evaporative cooling," according to PSFK. Considering that it may only be available three years from now, I guess it's good we're in heater mode.
The DEVap Air Conditioner Uses 90 Percent Less Power
Meghan Young — September 19, 2010 — Eco