Dan Koenck

Inside a building we found two of these panels, that hopefully show up in the pictures.
Can anyone tell me what they are used for?
They appear to be about 4x10 and 4 inches thick.
Thank you in advance.

If you don't get the plants covered in time and they start budding, can you still cover them with dirt and move to the next layer?

I was not sure where to post this but I have a question about 55gal plastic drums.
I have been given a bunch of plastic barrels and was told they would have to be rinsed thoroughly (but of course).
these blue barrels had Linear Alkyl Benzene Sulphonic Acid in . Can these be used to store water in for a green house? I'm sure aquaponics is out.

Thanks for the input. I figured I would make a RMH for my shop and if there were no issues, build one for a large enclosed, non-heated patio, although the size difference is quite large. I have purchased some firebrick from Menards with the intent of getting started but from the pictures I've seen, my bricks don't appear to be as heavy. They are 9x4.5x1.25. Are these big enough or do I need to make my own? I am actually sitting on what could be a gravel pit so the option for finding clay is pretty slim I think. I think the brain is currently on information overload.

Allen Lumley - Thanks for the help and the information. Absolutely love this place!

Thanks for the reply David. I'm wondering about length. does it matter if you run a 10ft pipe thru a bench or 16ft? I understand that it will heat either way but I'm just curious to know if it makes any difference as far as the length.

I am new here and would like to start by thanking everyone here for such phenomenal information. I stumbled across this website trying to find ways to be more self sufficient. We purchased an acreage almost 2 years ago and I told my wife that my goal was 3 years. We'll see how that goes!
Is there a table or chart or something that you can input information into for determining how much piping you need to heat a certain area or does it matter?
I thought about creating one if it was needed but thought i'd ask first.
We have several outbuildings here and I have more ideas than I do time and/or money so I figured I'd get the heat figured out first. NW Iowa get's pretty cold or at least this year it has.
I look forward to learning and again, thanks for having such an awesome place!
Dan