Geothermal Heating

[Michael Quinones]

Is anyone using geothermal heat to heat a green house.  For example pumping air threw a pipe burried in a trench 200' feet long 6' down?   Or pumping well water trew a hose under the stock tank? 

Maybe I should have asked the question before I burried the pipe Hmmmmm.

We are in Gainesville, North Florida I do understand the warmest the air comming out of the ground in this are will be about seventy degrees but at least we can capture that heat being cost effective.

 

[John Wroten]

Yes Michael, I put in the sub teranium heat and cooling pipes in my greenhouse. I have just been up and running about 2 months now, so I cant tell you alot. I am in Ky so now I am worried about the heating aspect. On a night that.outside temps are in the 20"s, with two 1500 watt heaters, I can mantain temps at the floor of 60 and at 6 foot, 70. The air coming out of my pipes under the floor is 60. On a sunny day the temps at the floor are 70, @ 6 feet, they can get to 110. I'm afraid to go to the top to see the temp there. My problem now is when the temps get so high on a sunny day, I have to open the door. When I do this the air on the floor gets cold, and this is the air going into my sub-terr, so I am not heating the dirt underneath.

As far as water pipes under the ground, when I went down 3 feet for the sub heating and cooling, I went outside the foundation and placed 180 feet of 3/4 in PVC 4 feet deep. I will use this to cool the water in my fish tank when summer gets here. I did place a home made solar water heater in the top of the greenhouse. I ran about 100 feet of CPVC pipe inside an insulated wooden frame with a double glass top. On a sunny day the water temps coming through this is 3 degrees warmer than the tank water.

I dont have it all figured out, but Rome wasn't built in a day...John

[TCLynx]

John, if you can figure out how to blow the hot air from the top of the greenhouse during the day into your under ground pipes, that will help warm the dirt and maybe help cool the greenhouse a bit without chilling the floor as much during winter.  And that warming of the underground pipes during the day will help at night.

[John Wroten]

TCLynx said:

John, if you can figure out how to blow the hot air from the top of the greenhouse during the day into your under ground pipes, that will help warm the dirt and maybe help cool the greenhouse a bit without chilling the floor as much during winter.  And that warming of the underground pipes during the day will help at night.

[John Wroten]

John Wroten said: The inlet to my under ground system had a wooden top with two inputs each with screen wire on the sides. I cut another opening in the top, placed a 12 volt moter that runs on a solar panel, and to this I ran a cloths dryer 4 inch hose going to the top of the house. The heat from the top of the house has to help, but to what extent, I dont know. Still when I open the door, cool air is also sucked into the under ground pipes. The constrution  is an on going chore, and I know when I put in my exhaust fan, it will help take the heat form the top of the greenhouse and keep the floor warm.

Thanks TCLynx for the come back....John

TCLynx said:

John, if you can figure out how to blow the hot air from the top of the greenhouse during the day into your under ground pipes, that will help warm the dirt and maybe help cool the greenhouse a bit without chilling the floor as much during winter.  And that warming of the underground pipes during the day will help at night.

[Japan Aquaponics - アクアポニックス 日本]

I saw something of this nature on a British TV programme.  A retired engineer from the British army has "gone green" and he did a series of programmes called "It isn't easy being green".  It is a really interesting programme if you can download it.  

In any case - he dug a hole in his greenhouse floor - lined it with heat insulation and then added heat absorbing material (in his case, crushed glass).  From that "heat sink" there is a PVC pipe that extends to the top of the greenhouse, and at the top of the pipe is a small fan that is powered by a small solar panel (something like a Computer fan).  During the daytime the fan draws air down into the heat sink, and then at night it stops.  The heat sink then radiates the heat stored, back into the greenhouse at night.  All very simple and cheap to put together... nothing fancy in there.

I am not sure if I have explained it well - but could something like this, in principle, work with what you have set up?

[Michael Quinones]

That is a very interesting concept.  I actualy recall reading some thirty years ago about a similar concept.  That one involved filing a pit with large river rocks pulling ait threw the pit from the cealing of the house during the day and in the evening continuing to circulate the air but in the evening you would be heating the air. 

Your explenation was great I don't know about broken glass .... Perhaps the glass dosn't have to be broken and that would create more air space Hmmmm.  I like this ....... thank you so much for the idea.
 
Japan Aquaponics - アクアポニックス 日本 said:

I saw something of this nature on a British TV programme.  A retired engineer from the British army has "gone green" and he did a series of programmes called "It isn't easy being green".  It is a really interesting programme if you can download it.  

In any case - he dug a hole in his greenhouse floor - lined it with heat insulation and then added heat absorbing material (in his case, crushed glass).  From that "heat sink" there is a PVC pipe that extends to the top of the greenhouse, and at the top of the pipe is a small fan that is powered by a small solar panel (something like a Computer fan).  During the daytime the fan draws air down into the heat sink, and then at night it stops.  The heat sink then radiates the heat stored, back into the greenhouse at night.  All very simple and cheap to put together... nothing fancy in there.

I am not sure if I have explained it well - but could something like this, in principle, work with what you have set up?

[Michael Quinones]

John I had the same concern about creating more heat in the green house in the summer but the temperature undergroung remains fairly costant.  In the winter we can raise the temperature with the air comming from the underground circulation but in the summer we should be able to cool the green house becase the air comming out of the underground pipes should be cooler than the air in the gren house.  Air moving threw a pipe for 200 feet I think has to aclimate to the underground temperature.

[John Wroten]

Yes Michael. The air coming through the  underground pipes now is 60 (give or take a degree). The man that I read from, that designs these systems give the computations for the fan needed to circulate the air. As it turns out, his comps say a small 12 volt, 4 watt fan made to cool a computer will work. I bought 2. I put one on the intake end, and one on the exhaust end. After a month of this, I decided this was not enough. I put a small 110 volt 8 inch fan on the exhaust end and cut a hole at the very peak of my roof and placed the unused 12 volt fan to blow hot air out on hot days. I attached a 4 inch flexable hose to the intake fan, and ran the end of it to the peak of the greenhouse. I can see a small degree of heat rise in the air coming from underground.

The designer said to use dirt as a back fill on top of the sewer pipe, but me being a "rocketscientist" decided to use rock. I put 6 inchs of rock on the pipe, then 6 inches of dirt ( gravel has gotten very expensive), another run of pipe, then 6 inches of rock, and so on until I covered it all with small gravel as a floor.

The designer said the in the heat of the summer, the underground cooling would not be enough. You would still have to have help. I entend to place a 21 inch exhaust fan in the peak, and I have a 4 foot window on the oppisite end of the greenhouse to open.

My biggest chalenge now is how to automaticly open an exhaust port when I am not around. Those solar powered openers, open at 70 degrees. I need something that would open at a much higher temp. I could sure use some help on this. Anyone. Thanks....John

Michael Quinones said:

John I had the same concern about creating more heat in the green house in the summer but the temperature undergroung remains fairly costant.  In the winter we can raise the temperature with the air comming from the underground circulation but in the summer we should be able to cool the green house becase the air comming out of the underground pipes should be cooler than the air in the gren house.  Air moving threw a pipe for 200 feet I think has to aclimate to the underground temperature.

[Michael Quinones]

John  I have burried "2 four inch flex drain pipes 6 foot down in a trench 200 feet long"  I will use a six inch bathroom exhoust fan (you can buy the fan by itself for about twelve dollars).  I hope this creates enough circulation.  It seams that there needs to be enough volume to make any diference.  If a computer fan works the bathroom exoust fan may move more volume.  But compute fans are built to un continuously a bathroom exhoust fan is not.  It may not last as long.  Time will tell.  

*****  Do you know how deep the pit with the glas was?  I figure at least 4 feet.  
 
John Wroten said:

Yes Michael, I put in the sub teranium heat and cooling pipes in my greenhouse. I have just been up and running about 2 months now, so I cant tell you alot. I am in Ky so now I am worried about the heating aspect. On a night that.outside temps are in the 20"s, with two 1500 watt heaters, I can mantain temps at the floor of 60 and at 6 foot, 70. The air coming out of my pipes under the floor is 60. On a sunny day the temps at the floor are 70, @ 6 feet, they can get to 110. I'm afraid to go to the top to see the temp there. My problem now is when the temps get so high on a sunny day, I have to open the door. When I do this the air on the floor gets cold, and this is the air going into my sub-terr, so I am not heating the dirt underneath.

As far as water pipes under the ground, when I went down 3 feet for the sub heating and cooling, I went outside the foundation and placed 180 feet of 3/4 in PVC 4 feet deep. I will use this to cool the water in my fish tank when summer gets here. I did place a home made solar water heater in the top of the greenhouse. I ran about 100 feet of CPVC pipe inside an insulated wooden frame with a double glass top. On a sunny day the water temps coming through this is 3 degrees warmer than the tank water.

I dont have it all figured out, but Rome wasn't built in a day...John

[John Wroten]

Again I agree. I liked the comp fan because it was only 4 watt. I have a battery in the greenhouse that is hooked to 20 watt solar panel, and I have a 600 watt converter standing by for an eventual power failier. I had a small (8 in) fan with a base that was used in the house to set in front of you for cooling. I hope this is a continuous use fan. Are you putting your 200 feet inside the foundation of your greenhouse or outside. I am thinking that the underground pipes are heating the whole mass of dirt and gravel that will act as a heat sink inside the house. I was recently given a fan that was used as a radiator fan out of an automobile. I thought this would be great (12 volt) but when I hooked it up to my battery to check it out, the small gauge wire that I had going to my existing fan got very hot, very quickly. There were no numbers as to what amp were written on the radeator fan. I still have it though, standing by, for future use. If you cant tell by now, I am a cheap skate. I dont have much mula. I have to improvise.....John

Michael Quinones said:

John  I have burried "2 four inch flex drain pipes 6 foot down in a trench 200 feet long"  I will use a six inch bathroom exhoust fan (you can buy the fan by itself for about twelve dollars).  I hope this creates enough circulation.  It seams that there needs to be enough volume to make any diference.  If a computer fan works the bathroom exoust fan may move more volume.  But compute fans are built to un continuously a bathroom exhoust fan is not.  It may not last as long.  Time will tell.  

*****  Do you know how deep the pit with the glas was?  I figure at least 4 feet.  
 
John Wroten said:

Yes Michael, I put in the sub teranium heat and cooling pipes in my greenhouse. I have just been up and running about 2 months now, so I cant tell you alot. I am in Ky so now I am worried about the heating aspect. On a night that.outside temps are in the 20"s, with two 1500 watt heaters, I can mantain temps at the floor of 60 and at 6 foot, 70. The air coming out of my pipes under the floor is 60. On a sunny day the temps at the floor are 70, @ 6 feet, they can get to 110. I'm afraid to go to the top to see the temp there. My problem now is when the temps get so high on a sunny day, I have to open the door. When I do this the air on the floor gets cold, and this is the air going into my sub-terr, so I am not heating the dirt underneath.

As far as water pipes under the ground, when I went down 3 feet for the sub heating and cooling, I went outside the foundation and placed 180 feet of 3/4 in PVC 4 feet deep. I will use this to cool the water in my fish tank when summer gets here. I did place a home made solar water heater in the top of the greenhouse. I ran about 100 feet of CPVC pipe inside an insulated wooden frame with a double glass top. On a sunny day the water temps coming through this is 3 degrees warmer than the tank water.

I dont have it all figured out, but Rome wasn't built in a day...John

[Kou]

Very interested. Can you guys post pics up? 

The biggest concern I have is heating the gh during the cold winter months in MI.

[Rob Torcellini]

I'm installing "geothermal" in my greenhouse.  I really wouldn't classify it as geothermal, but more of a thermal mass.  http://www.youtube.com/watch?v=sNIhxGjVcSM   it starts around the 4 minute mark if you don't want to watch me do concrete work.