Kyle Noe wrote: Up by the greenhouse, I've got the second handle done and I'm working on a solution to sealing up the gap around the handle shaft. Felt like the hours flew by and I was working at a snail's pace. I put the handles on and tried the latch out. The handles are so heavy they are making the latch slow to close. I'm going to have to increase the tension on the spring arms tomorrow.
Jim Siefert wrote:Interesting passive heat transfer solution I thought could be implemented in a wofati...
They are great for moving heat up. The problem is they only work to move heat up or at a very limited down. You need another system to move the heat down. The limit for the down is the wicking height of the refrigerant used in the tube. If the tube is lined with a wicking material they can be made to move heat down very limited distances but then you need lots of tubes and lots of transitions to make down work and the transitions from one tube to the next kill you. Think of them like an electric diode that only works one way.
They could be great for doing a freezer wofati or building a walk in cooler in a basement that ran without power for say 6 months of the year in northern climates. But the greenhouse needs a way to put the heat back down into the ground after it pull is out. So they are non ideal for it.
Country oriented nerd with primary interests in alternate energy in particular solar. Dabble in gardening, trees, cob, soil building and a host of others.
aerial picture of Allerton Abbey and the wofati greenhouse!
Kyle also postedhttps://permies.com/t/155/157417/permaculture-projects/Kyle-Permie-Bootcamp-BRK#1271490 some great pictures of the trimwork he's done on the interior (it's all finished!).
I read this book about the construction of China's railway line to Tibet. "Methods included using pipes called thermosiphons along the sides of the tracks to refrigerate vulnerable parts of the soil along the highest parts of the plateau, an area that comprises the largest continuous sub-Arctic permafrost region on the planet. These cooling sticks are 7.6-meter-long steel tubes drilled into the soil; they contain ammonia, which draws latent heat out of the soil as it evaporates. " Might this be an alternative to that hole/trench? It has no moving parts.
Bob, I believe it would require finding the exact pressure to ensure evaporation/condensation happens at the proper temperature, based on the subsurface soil temps. Say it's always 50*F 10 feet down, then the pressure would need to be adjusted so the liquid turns to a gas at 50.x*F, and as it rises up to the colder end it condenses and gives off that phase change heat. Then the pipe would need to be sturdy enough to withstand the increased pressure during the warmer months when the top of the pipe is much hotter, heating up the entire pipe above that evaporation point.
The holy trinity of wholesomeness: Fred Rogers - be kind to others; Steve Irwin - be kind to animals; Bob Ross - be kind to yourself
I visited the first wofati greenhouseproject site today. It was so beautiful, I couldn't take pictures of portions that were in construction... it would have been impolite. The thing is sooooo beautiful.
The temperature in the two thermal wells has been slowly yet steadily increasing. In the month of October of the first year, we saw an increase of around 0.45 degrees Fahrenheit.
Greenhouse-sensor-data.png
Reading the air at the bottom of the thermal well, 20 feet below the greenhouse floor.
Check out my Bootcamp Journal: Building and Growing at Wheaton Labs in 2022
How is the green house doing in the winter? Do you have any temperature logs from the November until now? Has there been and issues with the gray water freezing? Did you try to grow anything in there? If so how did it do
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