RANDOM THOUGHTS ON SOLAR ENERGY

As an outgrowth of our work on the Grieve solar heated home, a few of us here in Prescott, Arizona have formed a company called Arizona Sun works. One of our main objectives is to demonstrate that solar heating is possible now, and can be achieved without an accompanying 30-year mortgage. Members of Arizona Sunworks are presently building a house that will utilize the Thomason water/rock solar-heating system and a solar heated adobe shop. The shop will be the base from which we'll construct our own solar-heated adobe homes.

Our ground rules for design and construction are:

[1] build small,
[2] do your own work,
[3] allow available local materials to determine the type of construction and heating system you use, and
[4] build in stages. Building small-in phases-allows us to experiment, live with, and perfect alternative systems and skills while minimizing our capital fsrequirements.

The installation of a solar-heating system still demands for most people a significant investment in time and material. It's important, then, for anyone planning such an installation to evaluate his or her particular situation so that he or she may choose the right system for the application at hand.

Before starting construction of a solar heater, a person should be familiar with every design that's available, should understand the climatic conditions of the area in which he or she lives, and should know the heat load requirements of the building being fitted.

When an existing structure is retrofitted, it must first be evaluated for thermal efficiency and, if necessary, reinsulated. (Anyone who attempts to use "free" solar energy to warm a house that's a thermal sieve will be very disappointed.) Walls and roof should have a total thermal resistance of not less than 15 (one-fifteenth of a Btu passing through one square foot of wall every hour for every one degree Fahrenheit temperature difference between inside and outside). The building should be as tight as possible to minimize air changes. Perimeter foundations should be insulated, and windows double glazed or covered with heavy fiberglass drapes or movable insulated shutters.