Jump to content
smallblockfuelie

Geothermal heat sink greenhouse

Recommended Posts

Ive always wanted the ability to grow crops year around cheaply. Heating a greenhouse with gas is cost prohibitive, and wood heat is just a whole lot of work. I think Ive found a cheaper and easier alternative through a geothermal heat sink system.

 

So Im about to start a new project, a geothermal heat sink greenhouse. Im havng a hole dug and will filling it with 125 yards of rock. The rock will be 4 feet deep and will have two layers of perforated 4 inch Daumier drain tile. The bottom set of drain tiles, one every two feet, will be connected in a manifold (55 gallon drum) with a 6 inch inline fan attached. On the intake side of that fan will be some 6 inch PVC that goes to the peak of the greenhouse.

 

As the fun runs it will draw the hot air from the peak of the greenhouse, push it through the manifold and doen into 10 length of the the perforated drains tile. The air will be pushed up through the rock and transfer heat from the hot air into my screened sewer size rock (2-4 inch). Near the top of the rock will be a se onds et of perforated drain tile. The air will enter and be pushed back up into the greenhouse.

 

Between the rock and the walls of hole will be 4 inches of styrofoam. This will insulate the rock from the soil around it, helping to hold the heat in the rock for transfer back into the greenhouse after the sun goes down and greenhouse temps drop. Over the top of the rock we are putting a drainage fabric. It will prevent the soil from being washed down into our rock and perforated drain tile, but will allow water to drain. On the top of the drainage fabric will be 2 feet of soil. On top of that will be grow boxes where everything will be grown.

 

Im in 5b, but think this should allow me to grow year round and only require enough electricity to run the fan in order to keep the greenhouse warm. If I cant grow frost sensitive crops like tomatoes I can totally grow cabbage, broccoli, cauliflower and the like

Share this post


Link to post
Share on other sites

It'll probably do fine for you. I built a 14'x30', two story glass atrium on the back of one of my houses. Before they started work, I had a hole dug that was 8'x8'x8'. Ran a system of perf-pipe down in it and filled it with river rock. Ran a pipe to the top of the room with a duct fan that dragged the heat from the ceiling down to the bottom of the rock. It ran continuously. I was able to grow vegetables in tubs years round with no additional heat applied to the room from the house. During the Summer months, the sunken "room" actually allowed the air moving through the rocks to cool the heat of the room down some. Best of both worlds. I love passive solar. Good stuff.

Edited by Chris645
  • Like 1

Share this post


Link to post
Share on other sites

I have it up and running, finally.  We are planing our winter crops now and will get them started next month.  I am pretty excited to see how the greenhouse does this winter with hardy crops.  If anyone is interested in seeing what we have done, it is documented in this play list.  As winter gets here we will further document successes and failures.

 

https://www.youtube.com/playlist?list=PLgxEEe-u51rsDh8NFWEnU9BdCMTtQwqv8

Share this post


Link to post
Share on other sites
7 minutes ago, smallblockfuelie said:

I have it up and running, finally.  We are planing our winter crops now and will get them started next month.  I am pretty excited to see how the greenhouse does this winter with hardy crops.  If anyone is interested in seeing what we have done, it is documented in this play list.  As winter gets here we will further document successes and failures.

 

https://www.youtube.com/playlist?list=PLgxEEe-u51rsDh8NFWEnU9BdCMTtQwqv8

 

I am absolutely intrigued by what you are doing.

I hope it does very well for you this winter, and many more to come. 

The cooling in summer makes sense too, as Chris mentioned. 

Please keep us posted. 

 

May I ask what region of Missouri you are in ?

Is elevation involved ? 

 

Share this post


Link to post
Share on other sites
6 minutes ago, Retcop said:

 

I am absolutely intrigued by what you are doing.

I hope it does very well for you this winter, and many more to come. 

The cooling in summer makes sense too, as Chris mentioned. 

Please keep us posted. 

 

May I ask what region of Missouri you are in ?

Is elevation involved ? 

 

 

We are seeing a drop in the greenhouse temps of around 11 degrees after we turn the fan on around mid morning.  It absolutely makes a difference and helps cool during the summer.

 

We are in NW Missouri, rolling hills but no mountains.

 

I just created a new topic in this section that includes a link to a garden tour video.  You can see our results so far.

Share this post


Link to post
Share on other sites
5 minutes ago, smallblockfuelie said:

 

We are seeing a drop in the greenhouse temps of around 11 degrees after we turn the fan on around mid morning.  It absolutely makes a difference and helps cool during the summer.

 

We are in NW Missouri, rolling hills but no mountains.

 

I just created a new topic in this section that includes a link to a garden tour video.  You can see our results so far.

 

I was watching a bit of your videos when you replied.

Best of luck ! !

WAY  cool.

John

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

  • Recently Browsing   0 members

    No registered users viewing this page.

×