Online greenhouse heat calcs
Online greenhouse heat calcs
http://www.littlegreenhouse.com/heat-calc.shtml
most recent stuf I've read they use radiant floor tubing in raised beds to lower costs. A lot like the water troughs in the inca mountains (heat the soil to keep the plants from freezing with canals and the sun).
Mike
Murphys law 28th corollary- If there are five ways for something to go wrong, and you circumvent all five, a sixth will promptly develop.
Kwazai's addition- if you circumvent the sixth a seventh will develop, etc. etc.