I know all the reasons why air conditioning is less than environmentally-friendly. Air conditioning accounts for nearly 20 percent of total electricity consumption in U.S. homes -- even though it's not used year-round in most states. Worse than that, our inclination to refrigerate ourselves can actually make us sick, and the mold that likes to hide inside these machines loves to cause respiratory diseases and weak immune systems.
Honestly, I don't mind the heat, and can usually survive with a fan and a cold shower. But when the temperatures hang out in the triple digits for days on end, I start to have air conditioning-based fantasies. If only there were a way to achieve the rapid, whole house cooling of an air conditioner without all the negative side-effects. Well, according to a new DIY project making waves over at Instructables, the fantasy may soon become reality.
Tired of climbing into his car's black interior after it spent all day baking in the sun, the project's high-school-aged creator imagined an air conditioning unit that could be attached to the window. Devoid of electricity or a battery, this solar air conditioning unit would cool the car down without wasting any energy.
Based on the simple principles of convection, evaporation, and adhesion-cohesion, the prototype unit employs affordable materials and a simple design. "The sun will shine on the unit and heat the air at the bottom of the shaft. The air will rise, and also draw in more air from the bottom," writes designer fozzy13. "As the air rises, it will cause water in a small chamber to evaporate. When the water evaporates, it will take energy away from the heated air in order to change from a liquid to a gas. This will cause the surrounding air to get cooler. The water is brought into contact with the moving air by a piece of fabric. The fabric will pull up water from the chamber to increase the surface area of the water with respect to the moving air. As the water evaporates and the fabric gets dry, more water will be drawn up the fabric due to the awesomeness of cohesion and adhesion."
Check out the entire project here!