According to John Biernbaum–professor of horticulture at Michigan State University, “the first step in effective greenhouse vegetable production is selecting a greenhouse-friendly location.” Most importantly, he states, the site and orientation of the greenhouse should allow for proper drainage and water shed, and provide adequate sunlight.
If possible, the greenhouse should sit on elevated ground with a slope; this will move water away from the structure and help prevent flooding. Furthermore, the orientation of the structure will determine how much sunlight is taken in. *Ideal orientation will depend largely on which hemisphere the greenhouse is located in.
The greenhouse I will be designing is for the northern hemisphere (a latitude of 44 degrees), and meant to extend the growing season as far into winter as possible. So, the structure will need to be oriented so that light interception is maximized during winter months–taking into account the sun’s path. *Orientation refers to which way the ridge (the length) of the greenhouse runs.
It is important to note that the sun’s greatest height above the horizon always occurs at noon; and this (greatest) height is different according to the season, hemisphere, and latitude. It is always highest in mid-summer, and lowest in mid-winter. *In the winter, the sun stays close to the horizon.
Studying the sun’s path, one finds that–in northern latitudes (above 40 degrees) an east-west orientation works best to catch maximum light during winter, because it allows winter sunlight to penetrate the entire length of the greenhouse’s south side.
The angleof the sun-collecting side of the greenhouse is another important factor, as it also affects sunlight interception. *According to David McKinnon, author of The Solar Greenhouse, the optimal angle of your sun-collecting side can be determined simply by adding 20 degrees to your latitude.
In future posts I will discuss specific design features of (unheated) solar greenhouses–which is what I will be designing for the Rukmapura Park Hotel Property.