! heating greenhouse

I Love Living Farms. In this video at 1:25 min. it shows something like a climate battery but above ground.  They don't give the specifics of how much rock or how to connect the tubes.  Does anyone know the specific details on how to build these raised beds?



Here is the video that really explains  and gives details.

https://thelivingfarm.org/project/salad-greens-all-winter-with-solar-heat/

I had come to the conclusion to that a bed based climate battery would make sense for anyone not blessed with a backhoe.
I also saw combining  an ambient wood heater with  a climate battery as obvious.

Jacob Klingel actually acted on these ideas:

https://permies.com/t/231688/PAHS-High-Tunnel-Batch-Box

That living farm link is very nice!
The design of the beds uses common off the shelf components and is modular.

They have financial numbers for the crops produced and what those same crops would have cost of they had heated with propane, and the difference isn't even close.
The operation would have lost 1000s of dollars using conventional propane heat to produce the same crops.

I immediately wonder if supplemental lighting would have increased production enough to be worth while.
I think electric cable heat in the beds could be an affordable supplement the air to ground heat exchange.
The beds are covered with frost blankets every night, which is a significant amount of labor.
If the frost blankets were ridged insulation instead, that might improve heat retention and ease automation.
I'm thinking an aluminium faced foam board with hinges on the north side of the bed.
This could increase humidity inside the bed, which would probably be bad.
The article mentions using these to warm seedling trays.
I bet they would be great for propagating cuttings.

It all depends on the material, practicality of your location and resources available. The main concept is the same. The thicker the bed of rock, stone, dirt etc. the more heat it will hold. You can run a pathway of pipes underground and in between. You can do water or air(if you go under the frost level you're good to go).

There's a video on YouTube of a farmer in Nebraska that drove two holes in the ground, I think like 6 feet deep I forget. Then connected the holes with a 4 or 6 in corrugated pipe. Add a small fan on one side if you want. So essentially it pulls the cold air from the greenhouse pumps it down underground, heating the air, then the warm air come back up.

He grew all types of fruits and citrus in the middle of winter in Nebraska.

I remember place I grew up had a thick and I mean thick stone tiles, sort of like a stone deck.

I had some citrus trees in pots. Come to find out I forgot to take em inside the winter...them plants survived the winter and were thriving once spring hit. This was in the mid atlantic. Fairly cold winters you know.

I think all that stone absorbed the sun's heat throughout the day and probably kept the plants warm through the night and any freezing temperatures.

That is the best retrofit system I have seen.

On the frost blanket, there are manual and automatic roller systems that can reduce the labor for way less than the cost of a rigid system.