Geothermal Heating

[Mr. Ninja]

I wasn't sure where this would go, as there isn't any other place that was as close as this one, but here I go...

So recently I read an article about this guy who built a greenhouse that was heated geothermally. This is him.

I was wondering if that would be viable in aquaponics, especially here in Canada. The air would be heated by pipes running air underground, and the fish tanks could be heated by circulating water.

I was wondering, what's everybody's take on this?

Fixed the link, you just forgot the .com, that's all Jackalope

[badflash]

Can't follow your link but check this thread. I will be doing one of these this year.

How Would You Heat 5000 Gallons?

[bretthogan]

green house effect would possibly work, but i think the best bet would be either a wood fire stove with heating coil inside, or a thermosiphon design, but idk about in canada.

[badflash]

Sunny John is in Canada

[bretthogan]

http://www.monsterfishkeepers.com/forum ... pical-Pond

if that guy can heat 25000 gallons with wood fire/theromosiphoning you should have no problem heating a aquaponic system.

[15mules]

My take on Geothermal heating.
Geothermal heating and cooling in a house (its applicable, just give me a minute). The simple version. You dig a deep hole where there is a constant year round temp of say 45-60 degrees, depending on where you live. In the summer time you want your house 75 degrees. Now you run some lines down in the hole and you are cooling your freon with a much cooler medium, compared to just using outside air, which may be 80 to 100 degrees. The winter time comes and you want to heat your house. The heating unit can take 45-60 degree medium and raise the temp a little to get to your 75 degree comfortable temp, instead of using outside air that may be 30 degrees or colder. Keep in mind, we have no intention of cooling water, our main job in a home heating unit is to change the air temp, which is what we live in.
Greenhouse/ AP system cooling and heating. I am assuming we all plan on having an AP system of some sort in our greenhouse?? Now we have options as well as problems. I think we can also agree both our fish and plants live in water, not air! Correct?
The options. We can cool/heat the air (which is a terrible thermal mass, because it lacks MASS. Or we can heat/cool the water, which is a much better thermal mass, because, well, it has MASS). The water will easily help heat/cool the air. The air can not so easily heat/cool the water. For efficiencies sake, and because we agree both the fish and plants live in water, while only one, lives in both, we will focus on the water (the better thermal mass)
Ok, we have agreed on geothermal, or the hole in the ground, where it is 45-60 degrees. During the summer we circulate some water down in the hole and run it through a heat exchanger to take our, lets say 75 -85 degree AP water down a bit in temp., so it is better for our plants and fish. This works, we are transferring heat to the cooler ground below. Now it is winter time and our water is dropping down to say 58 to 65 degrees and we want to warm our water to keep our fish alive and our plants growing and most importantly our bacteria active to make the whole thing work. We circulate our water down the hole where it is 45-60 degrees??? Wait, this is colder than our AP system water, so how will it warm the AP system water?? It will not. But why did it work for our house? Because the air in our house is not a closed system, as our AP system is. The air in the house, must be exchanged with outside air or we die in our house from lack of oxygen. The water in our AP system does not have to be and should not be exchanged with outside water, it is a closed system.
Basic thermal dynamics. Just to be sure we are all on the same page. (please excuse me if you have a thorough grasp of this, I do not mean to speak down to anyone, just want to make sure for those who may not have a background in refrigeration we all understand the concept) An air conditioner, does not COOL the air, at all!!. But my house gets colder when I turn it on?? This is because thermal dynamic law says heat must move to a cooler place. The freon running in your ac is cooler than the air in your house. The hot air in your house must (by law) move to the freon. The freon is then circulated outside superheated, and the fan cools the freon, by making the heat leave the freon (by law) to go to the cooler (relative to the freon) outside air. This is why geothermal heating does not work so well to heat your AP water. If your AP water is 58-60 and your geothermal hole is 45-60, (by law) the only thing that can really happen is the geothermal medium ( the ground) which is cooler, must take the heat from your AP water, which is hotter. This is not what we want to do.
The best heating for our AP water in the winter, in my opinion, is to capture the radiant heat from the sun during the day (solar panels, heat sinks, etc) and store it in our thermal mass (also known as AP water) for use at night. If this is not enough, then we must burn something to heat the water, gas, oil, wood etc.