MoonShadows said: Take a look at the first picture in this article. ceresgs.com/solar-greenhouse-basics-insulating-your-foundation/ Of course, this is an extreme example
If I follow through this, I would dig it more than 5 feet. My frostline is at 30 inches. The temperature is constant at 2' -3' below the frost line. So, I would have to dig more than 5' to be perfect 🤣.
It would take me a long time to dig and get this greenhouse installed. I do it by myself.
So, that why I try to find an alternative way with minimize digging.
Instead digging too much. Can I just insulate the floor using reflective foam or EPDM rubber, then put a layer of paver/concrete blocks on it?
Of course, the insulation will be everywhere on the floor and touch the wall that is in the ground like 6" - 12" deep.
Since it is in the ground, I'm not quite sure if reflective foam or EPDM rubber better? I look it up a bit, it advertises that the reflective foam will not be disintegrated. But I'm not sure how it reacts when I put underground for years.
For the heater, I did the rough calculation using the cubic area of the greenhouse and estimated the heat loss. I came with a number that I need 1.3 kwh enegry for a night on the cold day.
Not sure if this number is too low. Maybe it is. Too many variable for the calculation while I can't measure it yet. It is hard to be accurate.
Once I built it and measure all the variable, it would be straight forward calculation though.
