Homemade AC Air Cooling unit produces very cold air. 40F air (in an 84F room). 3 ways to power it: a solar panel, a battery or an automobile (using 12v socket "cig. plug"). great for space cooling (in vehicle or small room). cost $15.00. $2 ice chest, $2 pvc pipe and $11 12VDC Fan (10w 0.8A). Fan runs on one 15 watt (1amp) solar panel. works best in dry climate. big block of ice i used lasted a long time. after 5 hours it was only half gone. check out my ice making/freezer vids if you want to make the ice "off grid"