iDRY Vacuum Kilns

Sponsors:

Inground heater for green house.

Started by Taylortractornut, June 12, 2011, 12:14:11 AM

Previous topic - Next topic

0 Members and 1 Guest are viewing this topic.

Taylortractornut

Im about to put up a 38 by50   Hightunnel/ green houe for my truck farming set up.      THe site is on the peak of a hill on an old home site.        Theres a 6 foot  drop off to  the natural grade of the hill its on.      Im about to remove the old parsonage house and   set up the greenhouse.      Id like to dig a hole in the embankment to  put in a large homebuilt heater.   I d like to run the   flue pipe under the soil in the greenhouse.    My reasoning is that I could  keep a big fire in the  heater and let the  flue heat the ground up.    This way thermal mass would keep the green house warm enough for the early  plants.   Id like to build my  fire boxe for a top load so I could use my skid steer to  load wood waste from work into it. 

I would have a few clean outs in it  to clean out the ashes that might get into the flue.   I figure the ground will soak up the heat and let it out slowly over night.     I have a  smaller hoop house thats 13 by 20 and  I heat it part of the winter with a   box or 3 inch rock burried in the center of the house and had a 4 inch pipe  run up to the top center of the GH.              In the middle of the  pipe i had a box with a small  electric fan that  sucked air in from the top of the pipe in the top of the GH.     It blew on the rock in the box heating it up from the bottom to the top.     At night Id reverse the little fan and it would put out 55 degres heat most of the night.
My overload permit starts after sunset

Holmes

Years ago you could get an 8" diameter cement pipe and use it for a buried flue pipe. It was about a half inch thick, and might have been made with asbestos.   You could use any 8" to 10" cement pipe and surround it with pea stone or small 1" crushed stone and that may work. Or you could use steel pipe. The 1" stone will give you a thermal mass you can blow air thru with a fan.
Think like a farmer.

OneWithWood

I would be concerned about creosote buildup in a horizontal flue giving up heat to the ground.
One With Wood
LT40HDG25, Woodmizer DH4000 Kiln

Holmes

When he said he could keep a big fire going in the heater I assumed he would and I assumed that it would not be an air tight stove. An air tight stove will develop a huge amount of creosote in this application.
Think like a farmer.

beenthere

Regardless if it is not an airtight stove or it is a big fire, the smoke/gases will cool quickly in the horizontal flue pipe and plug solid with creosote...prolly within a week or two at most. The soil/fill/stone around the flue pipe will keep it at around 100 deg F, and that is 'cold' when thinking smoke.

Better to pull heat off the stove to move through the horizontal pipe, and let the smoke/gases vent out a conventional chimney (straight up is best). 
south central Wisconsin
It may be that my sole purpose in life is simply to serve as a warning to others

Al_Smith

FWIW most likely that pipe which was mentioned was a product called "Transite " ,a mixture of Portland cement and asbestos .It isn't made any more .Never the less it was not an all fuel rated fuel, only for natural gas .

doctorb

Could you build a water jacket to the stove that circulated to a radiant floor in the greenhouse?  More expensive, I know, but no flue issues.
My father once said, "This is my son who wanted to grow up and become a doctor.  So far, he's only become a doctor."

Taylortractornut

 My fire box would be huge, I may make a short horizontal flu   just the heat one area.   If I could get the creosote in the flue to burn that would be good to lol.      I think a water jacketed set up woud be a bit hard for me to build.    I my just make a forced air   heater.  bt hte ground is what I need to warm.     I thing the heater hoses on the boiler would be a weak point under my beds.   I did see a wood fired water heater from Lemans  But Id like something I could loade with the loader and alot of wood. 

If I did used the water jacket heater I wonder if the soil will hold the heat and slowly release it.
My overload permit starts after sunset

Mooseherder

How many weeks is the temperature below 50 degrees where you live?

Taylortractornut

I live in NE  MS.    Right around starting time we have a big long cold snap February and March we get a snow or two.    If I can heat my soil I can hold over older plants in the ground for season extension.     I would settle for gettign the soil warmer to let off heat at night the help the pepper and mater plants.      I think I may be abole to make a large forced air woodburner to.  I may go that route with  hydronic coil attached to warm the starter beds.
My overload permit starts after sunset

Thank You Sponsors!