Solar air heater: Mounts on any sunny wall, turning solar energy into free heat for your home (Rodale plans)

Plastic comb bound paperback published by Rodale Press, 1981. Includes: Blueprints and construction manual to build the solar heater. Heater mounts vertically or horizontally; requires only hand-held power tools to build and install. Step-by-step instructions are directly keyed to the 6 pages of pull-out blueprints; works with or without fans, generating enough heat to heat an average-size living room all day long; possibly eligible for federal tax credit.