For those of you that remember my last post here is a very small update. Unfortunately work is crazy as it’s been warming up and my days off seem to be cursed by heavy rain storms but I was able to get the footers poured so now I can start laying the 6 courses of block for my foundation stem walls.
The middle will be filled with gravel after I get around to boring holes for my mini geothermal set up shown in the second picture.
by Light_Prudent
4 Comments
You should credit your second picture . It’s from the Regents of the University of Minnesota. It’s their deep winter greenhouse design. [https://extension.umn.edu/growing-systems/deep-winter-greenhouses](https://extension.umn.edu/growing-systems/deep-winter-greenhouses)
I had a climate battery like this. Two major problems with your design:
1. No need to intake air at the top of the greenhouse. To have proper heat transfer you need turbulent air flow through the ducts, which means a TON of CFM going through those ducts. That means air moving in the greenhouse. You’ll likely want HAF fans to stabilize the air once it gets into the structure and eliminate Hotshots. This means you won’t need that giant monstrosity at the top. Super challenging to install and not helpful.
2. Using crushed stone or rock makes sense in theory – it has a high insulation value so it stores heat well…which means it resists heat transfer well. This system requires heat transfer. Soil is a better choice as it’s a LOT cheaper and allows for heat transfer.
As someone who sunk a lot of time and money into one of these, my number 1 piece of advise is…..dont.
How deep you dug so far? How would you hold the walls against soils
So you’re not using tubes underneath? How will the air flow? If somehow in between the rocks then you’ll need a very coarse gravel and some super powerful fans pushing through AND pulling from the other side. I would run tests first, that seems risky compared to the perforated drain pipe method.