The solar industry is still in the throes of infancy . There are many different products on the market and no one is willing to say which is best, other than his own. those who venture to buy solar must have something of the pioneering spirit. They must make an investment decison based on information that varies from one source to the other.

The best source of information is people who already own a pool system and can tell how well it has worked and what their fuel savings have been. Ask the solar dealer for a list of his clients you can call.

The dealer should be able to tell you whether his solar components comply with ASHREA (American Society of Heating, Refrigerating and Airconditioning Engineers) testing standards. He also should be able to show you a performance curve-how much heat his collectors will deliver with differing amounts of light and outside temperatures.

Exhorbitant warranty claims should be mistrusted. Few solar companies have been in business long enough to honor them. Fafco, maker of plastic solar collectors, orginally guaranteed its product for three years and honored claims of collector failure. Its warranty has since grown to five, and now ten years.

The solar dealer should also service the equipment he sells and should write that into the sales guarantee. If you are the adventurous sort willing to buy equipment from a small company and install it yourself, you can find a complete list of solar equipment manufacturers at the Solar Energy Institute, Suite 800, 1001 Connecticut Ave. NW, Washington 20036 (202-293-2984).

The Copper Development Association Inc. distributes a booklet on making swimming pool heaters from copper components. The address is 405 lexington Ave., New York, N.Y. 10017.