Getting the wild ones this year

Steve Ebels_3

And where else do you go but to "The Wall"





My last post was inquiring about tubing the grade below a freezer. Now I have a customer who has a 32x 60 greenhouse under construction and wants to do root zone heating.  Anyone ever done that?



My questions are:



Do you insulate the sub strata, like down about 2-3 feet? He wants to grow tropical fruit like bananas and citrus and hopes to keep the trees in pots to move outside in the summer. (These will be very large pots, i.e. fork lift movable)



I know the edge insulation would be critical as usual, but then, if you insulate the "floor" at a depth of 2-3 feet you are basically creating a "tub" which I would assume could create saturation problems. Should provision be made for drainage?



The heat loss calc for the building itself is no problem but I'm struggling with how to account for heating up 40-50 tons of dirt to 55*  Talk about flywheel effect.........



Any input from the resident guru's?

clammy

my experences

Steve years ago when i did oil servie we had a custermer who did tropical plant rentals for the movie industry and all he had was 2 hortizontal hot air furnace using a sock pleum and his plants looked great .We also servied a larger farm which had radiant in ground and according to the owner they had installed hdpe boards about 1.5 ft below the surface which was gravel they did properly compress the base before installing the insulation.They also had secondary hot water coils with fans to help when  the garage doors where opened .the owner loved the system but claim that it was alot of money he still operates about 6 to 8 smaller green houses using standard hot air furnaces with the sock pleumes as i call them .You would think the heat exchanger would rot out with the fertilizer but he gets about 20 years out of them before they an no longer run properly due to the heat exchanger having cracks and the combustion chambers start being effected by the blower .Hope this helps you.Peace and good luck clammy

jp_2

maybe 5 ft down on perimeter insulation?

I might think about 5 ft down, heavily insulated, turning it into more of an isolated environment.  and maybe not even bother with insulating the 'tub' bottom.



what is the desired root temperature?