Dan’s soda can solar heater provides up to 120 degrees of temperature differential.
Ever since I built my first soda can solar heater three years ago, I’ve received plenty of input on how to improve the design for better heat output. For that reason, I never hooked up the first one – in fact, I gave it away to a friend – and set about building a bigger, better version, suffering through three cold winters in the garage. I started out by looking for a sliding glass door, which I found locally for free, then took all my measurements from that. Minus space for the insulation, the sliding glass door allowed for 180 cans (versus 50 for the first version), which took a while to accumulate, given that I’ve sworn off soda the last few years.
While Dan doesn’t provide many directions for his project, the blog entry for his first heater provides much more information.