[...]...1 THE SOLAR GREENHOUSE ENVIRONMENT The basic principle of the solar greenhouse is as old and uncomplicated as the practice of placing a glass lantern over a plant to protect it from the elements The glass creates a totally new environment within its walls, extending the productive life of the plant Now the solar greenhouse is coming of age The environment inside—slightly... Varieties Your greenhouse' s ability to hold the heat of the day is dependent mainly upon the design of the greenhouse Although greenhouse design is beyond the scope of this book, know that if your greenhouse is freezing your plants in winter, you need to review your solar greenhouse design Ifyourgreenhou.se freezes up, run through this checklist 32 The Bountiful Solar Greenhouse 1 Insulation—Is the north... front of a vent to the outside An exhaust 36 The Bountiful Solar Greenhouse fan at the opposite end pulls outside air through the wet pad, cooling the air, and the cooled air flows across the length of the greenhouse until it is exhausted to the outside This would be a complex system for a small greenhouse, but a simpler system described below can work using burlap and a fan Again, all of these evaporative... areas of the greenhouse and light colored rock on your floors The New Alchemy Institute placed white rock outside on 26 The Bountiful Solar Greenhouse the ground directly in front of the south glazing to increase light reflection into the greenhouse This is a good idea for cloudy areas of the country I've had a problem with slow summer growth in the area toward my north greenhouse wall when the sun angle... in the dead of winter See Greenhouse Food Crop Scheduling 24 The Bountiful Solar Greenhouse Type GREENHOUSE LIGHTING Supplemental to Natural Light • Lamp Life Appx Cost/ (1000s of hours) Sq Foot Comments Fluorescent Cool White 8-1 0 $3.50 8-1 0 $5.00 4-5 $5.0 0-$ 9.00 Expensive, but not much better, if any, response than the cheaper cool white lamps Slightly better flowering response Agrolite 5-6 $5.0 0-$ 6.00... forecaster to help make decisions about heating your greenhouse For example: it's a sunny winter day and the temperature inside the greenhouse has risen to 95°F (35 C) and is still climbing Tune in the weather radio for an up-to-date prediction for your area If the weather is predicted to turn 1 The Solar Greenhouse Environment 33 cold and cloudy, let your greenhouse run a little hot (but not much more than... one side and a low vent on the other side These should be either at the knee wall (south) and on the roof (north); or on the west and the east The high vent works best when placed opposite the direction of your prevailing summer wind and should be 15% larger than the low vent A general rule of thumb' is to have the vent area to the outside equal to at least 30 percent of the area of glazing Please... Department of Agriculture Handbook for the Home, Yearbook of Agriculture, 1973 Increasing Reflective Surfaces In the solar greenhouse sufficient light may be lacking, especially toward the west and east walls (unless they've been glazed) To make matters worse, the northem part of the greenhouse is low on light during the summer when the sun angle gets high As most solar greenhouse construction books explain,... 3 Turn on the exhaust fan at the opposite end of the of the greenhouse to draw air through the wet burlap, cooling the air as it passes through It's cheap and it works well Just don't count on reusing the burlap bags to transport potatoes at a later date Some greenhouse owners have turned to using an actual swamp cooler attached to the side of the solar greenhouse, pumping cooler air into the structure... and other automated machines to create the desired environment Despite the outside goings-on of cloud cover, temperature swings, etc., the environment in a conventional greenhouse is maintained unchanged I personally find a special connection to the earth in a solar greenhouse, which is affected by the outside elements on an hourly basis Each cloud, storm, hot spell, cold spell is part of the solar greenhouse . fun. Shane Smith Somewhere in the Rocky Mountains, 1982 (For more information on the Cheyenne Community Solar Greenhouse see the Epilogue.) 1 THE SOLAR GREENHOUSE ENVIRONMENT The basic. major impact on greenhouses, and the development of pre-fab quonset-type structures greatly changed the commercial greenhouse industry. In the early 1970s the concept of a solar greenhouse began. the plants they contain. The second category is the commercial greenhouse which bears about as much resem- blance to the first type as an apple to an orchid. The first rule in commercial greenhouses,