Rob Taisey, of Assured Solar Energy, will be installing a solar air heater on the south facing wall of Chewonki’s Wallace Center Dining Hall. The solar air heater will transform solar energy into heat, which will then be dumped into the Wallace Center at a rate of several hundred BTUs per day.

Solar air heating is a simple and direct approach to using the sun’s rays to warm your home. Previously dubbed by Popular Science magazine as one of the “100 Most Technologically Significant Products of the Year,” a solar air heater offers interesting and economical solutions to conventional heating methods. A solar air heater can reduce the average home’s heating costs by 20-30 percent.

How it works

A solar air heater is essentially a flat box with two essential parts – a sheet of glass and a sheet of metal. The glass functions to allow sunlight to enter into the collector, but retains the heat (the greenhouse effect working in our favor). The sheet of metal is required to absorb the sunlight and turn it into heat. The metal is usually painted black to absorb the maximum amount of light energy. And that’s essentially it: the sunlight passes through the glass, is absorbed by the metal, and heats up the inside of the box.

courtesy of greenelectriconline.com

All that is required now is to let the hot air enter your house – some models use a tiny fan to move the air through, others use simple convection (heat rises) and have no moving parts. With either model, the beauty of a solar air heater is in its simplicity – simple design, simple (and inexpensive) parts, and simple use.

How to use it
The effectiveness of a solar air heater is dependent on a number of factors, such as ensuring it is placed in a south facing location to maximize the direct sunlight and taking into account roof overhang and shading from nearby trees or structures. To prevent your house from losing heat through the solar air heater at night, most are installed with one-way vents, to prevent any air exchange when the solar air heater is not producing heat.

Chewonki sports both professionally built and homemade solar air heaters on its campus. The homemade solar collectors are made by students of Maine Coast Semester.