PDA

View Full Version : Heating and cooling with a geothermal loop


coryjones
10/07/2008, 07:38 PM
has anyone done this i have a 220g tank and 75g sump and running 3 400w mh. I was thinking of digging a hole out side throwing a loop of plastic tubing in it and using the ground temperature to cool the tank.
I am just not sure what size tube to use what length and if i dig a 3' hole if it would be enough or if i should go with a long horizontal loop. I don't know what flow to go with as well? I would like to have some type of controller to shut a pump on or off it gets to cold. Doe's anyone know of a controler or anyone that has done this? The ground temp should be 50-60deg at 3' around here year round. I am a hvac installer and have put in many geo units to heat and cool houses. So i am not new to this.

SWINGRRRR
10/07/2008, 07:55 PM
Theres a ton of threads on here about it. Try a search.

I never attempted it, or see it as an option. Its just not feasible for my location. But it seems that others have attempted this.

NewBostonConst
10/07/2008, 08:20 PM
I think you idea is great and will definitly work. But another way to do it would be by just adding another large tank to your system. This will give you more water for stability and cooling. I have bought a 150 gallon for $80 and a 80 gallon for $60 both used but in good shape.

BeanAnimal
10/07/2008, 08:25 PM
You are going to need more than a hole and a loop of tubing... you will quickly saturate the ground with heat from the tank. You will need a horizontal loop of substantial length at least 3' deep. There are some threads with the math. You will not want to run tank water through the loop (for MANY reasons). You will need to setup a heat exchanger and temperature controller to turn the loop on and off.

coryjones
10/07/2008, 09:32 PM
I have found some threads where people use tank water and i don't see any reason not to it is not possible to drop a loop in my sump just not enough room. I don't have the room to add any more water volume. I have it setup now 220 upstairs with 100g stock tank ans 29g fuge down stairs and i am going to move and go to a 220g display and 75 sump that will house fuge and skimmer. Everyone says the inside of the pipe will grow closed with algae or what not the pvc that runs from up stairs to down now has been in use for 2 years and there is almost nothing in it.

BeanAnimal
10/08/2008, 07:26 AM
<a href=showthread.php?s=&postid=13504733#post13504733 target=_blank>Originally posted</a> by coryjones
I have found some threads where people use tank water and i don't see any reason not to it is not possible to drop a loop in my sump just not enough room. I don't have the room to add any more water volume. I have it setup now 220 upstairs with 100g stock tank ans 29g fuge down stairs and i am going to move and go to a 220g display and 75 sump that will house fuge and skimmer. Everyone says the inside of the pipe will grow closed with algae or what not the pvc that runs from up stairs to down now has been in use for 2 years and there is almost nothing in it.

If you run tank water through the loop:

The detritus WILL settle in the pipe. The detritus will rot and you will have a phosphate/nitrate farm.

The long, pitch black run WILL grow sponges, tube worms and other structures that will trap detritus. It is horizontal, not vertical! The structures will coat the walls and cut down thermal efficiency AND/OR end up restricting/resisting the flow.

Bacteria will grow in the loop and deprive the water of oxygen on its long trip (along with the rotting detritus)

You will not be able to turn the loop on and off to control temperature it will have to run 24/7 or the water will become anerobic very quickly.

You run the chance of a leak draining and/or contaminating your system.

coryjones
10/08/2008, 04:29 PM
So what do have to back this up? Not being a *** just woundering a lot of people say a lot of things ya know i cant see it growing to much with no light. If it works for a couple years it will be worth it. I am looking at dropping $700 on a chiller otherwise.

das75
10/08/2008, 06:29 PM
Why would a geo-loop be such a hazard compared to a denitrator coil (http://www.reefcentral.com/forums/showthread.php?s=&threadid=1014664&highlight=pvc+glue) .

Other than one coil is in the ground, other in a dark container, seems the same idea in principle, flow water through tubing. If anything would assume with a open geo-loop you could also have the advantage of reduced nitrates.

Have neither, my comments are for discussion.

BeanAnimal
10/08/2008, 06:55 PM
Very simply, the volume and flow of the loop.

Also, a misadjusted denitrator can cause very serious problems.

areze
10/08/2008, 06:58 PM
Id start off seeing if you need a chiller.

not every large tank with MH needs a chiller. few fans and you might be fine.

sjm817
10/08/2008, 08:15 PM
I've been to Dr Mac's Aquaculture, and they have the whole place on a geothermal setup. They have a decent size piece of land, so I'm sure the setup is pretty large.

coryjones
10/08/2008, 10:12 PM
I no i will need a to cool the water in the summer. I am reducing my water volume by 50 gallons when i move and right now at 76 deg in the house the tank is up to 83.6 what is it going to do when it hits 80 or 90 i don't always run the air it is nice sometimes to have the windows open. 1200wats of light on ths tank has raised the temp quiet a bit. i have fans on the reflectors now

http://i252.photobucket.com/albums/hh20/coryjones/220%20build%20up/IMG_6803.jpg

http://i252.photobucket.com/albums/hh20/coryjones/220%20build%20up/IMG_6844.jpg

http://i252.photobucket.com/albums/hh20/coryjones/220%20build%20up/IMG_6855.jpg

BeanAnimal
10/08/2008, 10:51 PM
I hope that is not copper pipe that you are using to hold the lights up!

The fans on the lights are not going to help much in the way of preventing heat transfer. The fans would do a LOT more cooling if they were blowing at the water. Evaporative cooling is the most efficient way to keep a tanks temperature down (over 8,000 BTU per gallon).

coryjones
10/08/2008, 10:52 PM
copper looking paint

BeanAnimal
10/08/2008, 10:55 PM
:)

coryjones
10/08/2008, 10:56 PM
Been down this road lol i just like the look of copper.

8BALL_99
10/09/2008, 01:06 AM
<a href=showthread.php?s=&postid=13509437#post13509437 target=_blank>Originally posted</a> by coryjones
So what do have to back this up? Not being a *** just woundering a lot of people say a lot of things ya know i cant see it growing to much with no light. If it works for a couple years it will be worth it. I am looking at dropping $700 on a chiller otherwise.

LoL, Not sure what you need to back it up.. If you run tank water through the loop instead of doing a closed loop you will have all the problems listed above.. You don't need light for sponges and feather dusters to grow. Just look in a sump of any tank that is established. The water will become anerobic if you ever turn the loop off for any length of time. So if you can't ever turn the loop off it would be like running fans and your heaters at the same time..Pointless. The other issue is if you ever get a leak at any point in the loop you just added a drain to your tank that is several feet below your sump. A geothermal loop isn't a bad idea and has been done by tons of people, But running tank water through it is just a bad idea..

8BALL_99
10/09/2008, 01:07 AM
Yikes you cut holes in the top of your reflectors to mount fans?!

coryjones
10/09/2008, 09:36 AM
ya and it drop the tempture from 180 dep in the light housing to 119. I figure if i can get the heat away from the tank it will stay cooler.

<a href=showthread.php?s=&postid=13512338#post13512338 target=_blank>Originally posted</a> by 8BALL_99
Yikes you cut holes in the top of your reflectors to mount fans?!

BeanAnimal
10/09/2008, 09:43 AM
Most of the heat transfer to the tank is via radiation, not convection. You cut holes in the outer shell, not the reflective material correct?

8BALL_99
10/09/2008, 09:45 AM
Biggest issue with that is you cut out the reflector directly behind and the sides of the bulb. A fan pointing across the top of the tank would have did more for your temps with out hurting your light output.

8BALL_99
10/09/2008, 09:51 AM
<a href=showthread.php?s=&postid=13513747#post13513747 target=_blank>Originally posted</a> by BeanAnimal
Most of the heat transfer to the tank is via radiation, not convection. You cut holes in the outer shell, not the reflective material correct?

Cross post, I see yeah it looks like he didn't cut the reflector just the outer casing. Thats not a big deal then. That will keep the reflector cooler but won't do much for the tank itself.

coryjones
10/09/2008, 02:19 PM
It isn't going to hurt the tank either for the 100ma it is drawling.I seemed to make a diffrence and you can't even see them or hear them.

BeanAnimal
10/09/2008, 06:39 PM
No it is not going to hurt the tank :) However, the same 300ma would do a LOT more cooling if it were used to aid evaporation. You get over 8,000 BTU of cooling per gallon of evaporation. Keeping air moving over the surface of the water will greatly enhance evaporation :)

coryjones
10/09/2008, 06:57 PM
Got the covered on the sump down staris the furnace a/c vent blows across it.I don't really have a problem with cooling just yet. I did pick up a reef keeper 2 to controll fans chiller or loop.