solar air heater. solar air heat collector. simple to make. solar panel runs blower fan. no 'grid power' or batteries needed! hi temps. 150F (65.55C) and higher. great for space heating. cost effective way to heat home, garage, shed, greenhouse etc... solar heated air can reduce the heating load during the daytime, thereby reducing your power bill (and carbon footprint). works great in cool and sunny conditions. simply face it towards the sun (south in northern hemisphere) and duct it into desired building space. this 'space heater' will heat a room and assist in heating house. expand it to size. DIMENSIONS: glass/plexi-glass - 18" by 24". external diameter of cardboard - 18" by 24". cardboard rails are made with 3 to 6 pieces (glued and pressed). they are 3" wide and about 3/4" thick. wood frame is made from one 8ft long "one by four'. true dimension is 3/4" thick by 3 1/2" wide. side rails are 29" long and top/bottom rails are 18 1/8" long. solar panel is 6V 250ma (1.5 Watt) from Radio Shack ($15.00). most computer cooling fans can be run on either 6V or 12V solar panel. I have seen similar solar panels on EBAY for as little as $5.00. harbor freight sells a 12V 1.5 Watt panel ($12.00) that would work well with this too. computer cooling fan is from Frys electronics ($5.00). those can just be salvaged from an old computer. i will be sealing /weather-proofing this heater.