Rick Stelter

Rob Evers wrote:I will have to check on that.  Thanks.  What size do you all think would be good.  I was thinking of doing 16x40

I think that is an excellent size. Not too small, which leads to tempature control problems, and not so large as to be too much to take care of in a reasonable amount of time.
You also may want to consider thermal mass to moderate temps as well.

S Bengi wrote:Heater:
Plants like the extra CO2, so I would place the heater inside the greenhouse vs outside. The radiant PEX pipe heating sounds like a wonderful idea to warm the soil vs just the air.

Insulation:
I recommend insulating the floor and walls that are in contact with the soil. This would be with regular EPS foamboard, same as the ones used in houses.

Glass/Roof Insulation:
Normally the "glass" is not insulated. You could get a double pane/layer "glass", polycarbonate sheet or inflated poly-film. they do have some roll down "blanket" mats for a few Chinese style greenhouse but then you have roll them down and roll them up, and remove snow. Yes remove the snow, which to me just sounds like a type of punishment.


Have you considered a Beadwall system?  Google it and Zomeworks.and  It's somewhat technical, but the airport in Aspen, Colorado had one.  It was fascinating to watch. 6 inches of beads is abour R-15..