PC-Solar Reviewed by Dan Lepinski Computer programs to make better use of solar energy in buildings are beginning to make their appearance in the marketplace. Some require that you have a PhD to use interpret the results. PC-Solar is a pleasant exception. The Program PC-Solar is a computer program that's intended for use by architects, designers, engineers, contractors, and builders. It has but one purpose; to assist with the design of windows and shade overhangs. PC-Solar will run only on PC style computers. It requires at least 640K of RAM, DOS 3.0 or higher, and a VGA monitor. A hard disk is mandatory as PC-Solar, stored in a "compressed" form, expands out to nearly 1.5 MB when installed. A Hewlett-Packard (or compatible) laser printer or 9 pin dot matrix printer will provide printed copies. The manual doesn't state the minimum processor required, but based on my experience, the bigger and faster the better. Getting Started You don't have to be a computer genius to use PC-Solar. The instruction manual is well written and guides the first-time user through the simple automatic installation procedure. Both 5.25 inch 360K disks 3.5 inch 720K disk are included in the program package. To me, a well written program means I don't have to wear out the manual and telephone trying to learn how to use it. PC-Solar succeeds on both counts. In spite of the fact that I am not an architect, I was able to start and run PC-Solar immediately. The Instruction Manual PC-Solar is provided with a concise and clearly illustrated 22 page manual. Terminology is often explained with examples that help to visually explain some of the complexities in something as deceptively simple as windows and overhangs. Numerous references to other sources of information are also included. Performance At no time did I note any defects or incorrect answers. In fact, PC-Solar kept me from accidentally entering some grossly incorrect values. At no time did the program freeze or cause strange things to happen on my computer. The manual does warn that some invalid data can be entered that will result in some bizarre results. It is up to the user to make sure the information you enter is accurate. Mistakes are easily corrected as the program allows quick and simple editing on the screen. I tried the example in the manual and understood the results without difficulty. A real life example of our planned solar home also worked well. I particularly enjoyed the "animation" feature included in PC-Solar. It creates several window models on the screen showing the effects of different seasons and times of day on the sun angle and shading. It takes a little time for the computer to set up the animation, but the results are worth the wait. This is a really neat feature. PC-Solar calculates angles and displays shading for all sites in the contiguous 48 states. An internal list of more than 30,000 U.S. cities and 45,000 ZIP codes makes calculating latitude and angle information a snap. PC-Solar can also calculate solar angles and display or print solar collector incidence charts to help orient solar collectors to the optimum angle for energy collection. Cost PC-Solar is $45 a copy within the United States or $55 elsewhere. Site licenses for only $15 per additional computer are also available. Group purchases in quantities of 10 or more are offered for $27 per person. Considering the obvious work that went into the software, this is very reasonable. PC-Solar carries a 30 day money back guarantee. This says a lot for the authors and their confidence in the program. In addition, free updates are offered if any of the math formulas are found to be in error. Conclusion PC-Solar can be a useful tool to anyone designing windows, shades, and overhangs. It is a quality software package that should be found in the office of any solar-minded designer, architect, engineer, or builder. Access Author: Dan Lepinski, 5905 NE 111th Street, Vancouver, WA 98686 ¥ 206-573-6596 PC-SOLAR, 3-D Software, Carlos Portela, POB 1373, Poway, CA 92074 ¥ 602-795-0284