As many of you know, a conservatory is being constructed here at Our Little Acre. It started out being called a greenhouse, but since technically a greenhouse is all glass or polycarbonate or some-other-clear-material, what we have going up here isn't a greenhouse. It's a conservatory, which is a room with a lot of windows that allows enough light in to allow plants to grow well.
Construction was begun while Mom and I were in Dallas for the Garden Writers' Association annual symposium at the beginning of September. It required that I move quite a few plants, which wasn't an advisable thing to do when we were in the middle of a drought and experiencing above normal temperatures, but you do what you have to do. At this point, it looks like all have survived except for a tree peony. :-(
In the matter of six weeks, we have gone from this...
Which brings us to this point: Which kind of propane heater is the best to use for heating the conservatory? I want to keep it at 60° F or a little higher for the winter. We're in Zone 5b, so our average lowest temperature in winter is -10 to -15 degrees F. The building is 10' x 12' with an open ceiling height at the peak of approximately 10 feet. It will be insulated on all four walls and the ceiling with R-19 fiberglass insulation.
So...which is best? Vented or ventless? My issue with ventless is the automatic safety shut-off when the O2 level reaches critically low levels. Good for humans. Bad for plants that you don't want to freeze. If I have to have a source of fresh O2 so that the ventless heater doesn't shut off anyway, then wouldn't vented be the way to go? And what about blue flame vs. radiant? Any thoughts on that?
The propane tank was set in on Friday and now we just need a heater to attach to it.
What I'd love is for greenhouse owners, greenhouse sellers and anyone who has any experience with either or both of these type heaters to weigh in here so we can make a decision about this. I'm counting on the rest of the gardening world coming through for me with their sage advice! Have at it! I'm all ears!