The Owner Built Home & Homestead
(Page 3 of 7)
July/August 1972
By Ken Kern
Soon after learning of Went's greenhouse research I had occasion to include an unheated pit greenhouse into a rambling, adobe ranch house designed for the Morgan Washburn family in Oakhurst. About the only unique feature of this greenhouse (besides the obvious pit-heating effect) was its incorporation as an important annex to the house; one could stand in the kitchen and pick salads from the greenhouse bench.
RELATED CONTENT
Placebo effect: Belief in a treatment helps you feel better, a powerful plus, scientists say...
THE GREENHOUSE EFFECT February/March 1994
LAST LAUGH
Too much oxygen ca...
Inherited obesity: A fat woman's womb may nudge her children toward becoming obese later on...
Experts warn glaciers in Indian Kashmir melting at alarming rate due to climate change...
BITS AND PIECES January/February 1975 SO WHAT IF THE ARMY KILLS 14 MILLION BLACKBIRDS? The U.S. Arm...
Tom Powell featured the Washburn greenhouse in an article for ORGANIC GARDENING AND FARMING magazine (January 1959), and notoriety from this item helped to initiate me into an expanding fraternity of greenhouse freaks — designers, builders and growers. For the next ten years I amassed an impressive working knowledge and greenhouse construction experience. I found greenhouse enthusiasts to be, on the most part, exciting and imaginative people. Witness the Nearing 9 by 18 sun pit, which Helen and Scott kept active all year in Vermont: tomatoes and peppers were grown through the summer months; Chinese cabbage, celery, parsley and chives all winter — with no supplemental heat!
There are both ephemeral cranks and foremost representatives of science involved in the study of forcing plants in artificial stricture. Sometimes the sifting out of the true and beautiful is not all that easy; even the scientific opinion raises questions and problems that seem unanswerable in our lifetime. But there is much of this information that can be used to advantage by today's homestead builder. Are you ready?
Let's begin again with light and heat. To function properly, a greenhouse requires maximum light. But admitting desirable light also admits a possibly excessive and undesirable temperature buildup. High temperature causes plant respiration which tends to disturb the metabolic process. It is the infrared — the heat — region of the solar spectrum that causes this temperature increase. The greenhouse operator who customarily paints whitewash on the glass for shade, thereby reducing entry of shortwave rays, is sensitive to plant respiration. Opaque shading is a shortsighted solution, however, because the balance of light rays (fully onehalf of the rays) is thereby inhibited on the other end of the spectrum, restricting the narrow ultraviolet (shortwave) rays.
The "greenhouse effect" also takes place as a result of faulty (e.g., standard) greenhouse design. As the contents of a greenhouse are heated, this interior heat is given off in the form of infrared radiation. Though given off, the heat never leaves the greenhouse: window glass does not transmit longwave infrared radiation. Heat consequently builds up inside, and plants "burn". Furthermore, window glass admits only about 5% of the ultraviolet rays, which really makes glass a health hazard for man as well as for plants. Ultraviolet radiation controls bacterial and viral populations, and when the rays are filtered out upper respiratory troubles are apt to occur, especially during winter months in cold climates.
Page:
<< Previous 1 |
2 | 3 |
4 |
5 |
6 |
7 |
Next >>
