This a growing field and will become more important over time as urban spread swallows up farmland. My family has a 1 acre size greenhouse from 1976 and it is very hot working in there despite the cooling fans.
Micki, the only mistake you make is about pests and pesticides.
As a greenhouse is a closed system, pests can thrive rapidly to plague proportions and pesticides have to be used. Unfortunately.
The goal is to keep them out, but nature is always on the move, and pathagins are mostly overlooked untill they suddenly appear. Above and below ground.
John van Heerden; South Africa