Page 14 RAIN May 1981 SOLAR GREENHOUSES -- -- . - --- - - - - ----- - - - - - - - - - - - - Low-Cost Passive Solar Greenhouses, by Ron Alward and Andy Shapiro, 1980, 173 pp., $5.00 from: National Center for Appropriate Technology (NCAT) P.O. Box 3838 Butte, MT 59701 Solar Greenhouses Livin~ and Growing, Proceedings of the Second National Conference on Solar Greenhouses, 1979, 328 pp., $14.50 (includes postage) from: New England Solar Energy Association Box541 Brattleboro, VT 05301 Hands On!, How to Give an Attached Solar Greenhouse Construction Workshop, 1981, 49 pp., $6.00 from: Portland Sun 628 SE Mill Street Portland, OR 97214 Most of the literature on solar greenhouses is, by design, an overview. Rarely do books get down to the kinds of problems, solutions, and monitored comparisons that these three books cover. When I used to lecture on solar greenhouse design, construction, and horticulture, I found myself recommending very few basic texts: The Solar Greenhouse Book (Rodale), The Survival Greenhouse (Walden Foundation), Winter Flowers in Greenhouse and Sun Heated Pit (Scribner's) and the Proceedings from the First National Solar Greenhouse Conference (NESEA). I've maintained that small list (perhaps suggesting region or topic specific additions occasionally) as general "best reading" till now. Suddenly there are three additions I'd make. Low Cost Passive Solar Greenhouses has the overview of some of the earlier books, and is really not all that unique in focussing . on low cost, but shines nonetheless in two areas. The construction details are the very best I've seen. For example, until only re-· cently even manufacturers of corrugated fiberglass reinforced plastic (FRP) provided only vague instructions for its installation: You were left to either figure it out for yourACCESS ~ I , ·:~....:._ . <1;; ,,I ) self or ask someone who'd done it correctly (if someone so experienced was handy). The NCAT drawings and text are so clear and simple I have difficulty remembering why the process ever baffled me when I was beginning. The other area where this book excels is in its section on venting and cooling systems, subjects rarely explored adequately in more general books. Earlier greenhouse books suggested ways to cope with the rapid depletion of carbon dioxide (CO2) in solar greenhouses where the reduction of air infiltration creates critical shortages, reducing photosynthetic reactions to near standstill. Most of the methods were untried and unmeasured. Solar Greenhouses Living and Growing introduces work being carried out at the New Alchemy Institute that utilizes composting in the greenhouse for both CO2 and heat production. Robert Sardinsky's paper describes their work with compost and the monitored results. The information is very encouraging for greenhouse operators. Other papers in these proceedings afford us the same sort of specific detailed data on topics as diverse as "Comparison of Tomato Yields as a Function of Light Levels in a Northern Solar Greenhouse" by Miranda Smith, and "Community Solar Greenhouses; Some Important Social Considerations" by Nadia Beiser. A large number of greenhouses are being constructed on the barn-raising model with teams of people who learn while doing. Portland Sun is a small collective that has led over 300 people in more than 20 workshops building both solar greenhouses and simple __;}~:\f~·::.•.:.. ~tr hot water systems. Their experience shows in the guide they've produced for future workshop coordinators. You can avoid much of the trial and error syndrome by taking to heart the lessons they've learned. "There's a lot to do if_you're going to plan, run, and follow up on a workshop. Therefore we're describing necessary jobs and listing them in the order in which they are likely to occur." Besides just good advice, this booklet offers useful bibliographies, seed sources, sample public service announcements and press releases, and more. If you're ready to move from beginners' texts to more advanced ones, try these three. -CC /.r.,,-TMM FIGURE 7.9 Corner detail -corrugated FRP glazina °"'~ ,r-,-,,, cur ,r,A.IXRW.-- a,._;_. __ --Cl-- -,-0"7/r FIGURE 7.10 Application of corrugated FRP glazing
RkJQdWJsaXNoZXIy NTc4NTAz