Crazy Aquarium Geo-thermal idea

[Splat]

Since the topic of geo thermal came up earlier this week, it got me thinking.

On my reef aquarium I have to run a homemade chiller to keep the water temp down with the use of HQI lighting and such.

So a thought occurred, why not run piping underground and circulate the water from my sump through it to keep the water temps down where they need to be, using the earth as a heat exchanger.

Any reasons this wouldn't work? Running a chiller is like running a air conditioner year round plus running the circulation pump, its a bit expensive. How long of a run would I need? And how deep would I need to bury the pipe in northern ohio? Come on guys let's think this one out.

I need to do some yard excavation next year so ripping up the yard isn't a concern.

Bill

 

[marlboro180]

Re: Crazy Aquarium Geo-thermal idea

Since the topic of geo thermal came up earlier this week, it got me thinking.

On my reef aquarium I have to run a homemade chiller to keep the water temp down with the use of HQI lighting and such.

So a thought occurred, why not run piping underground and circulate the water from my sump through it to keep the water temps down where they need to be, using the earth as a heat exchanger.

Any reasons this wouldn't work? Running a chiller is like running a air conditioner year round plus running the circulation pump, its a bit expensive. How long of a run would I need? And how deep would I need to bury the pipe in northern ohio? Come on guys let's think this one out.

I need to do some yard excavation next year so ripping up the yard isn't a concern.

Bill

Should be pretty simple- some sort of heat exchanger and a flow valve...cool idea, pardon the pun. Groundwater by me is 50 ish at the top.

 

[Bondo]

Re: Crazy Aquarium Geo-thermal idea

How long of a run would I need? And how deep would I need to bury the pipe in northern ohio?

Ayuh,.... I imagine the length of the run would depend on What you're running...
Copper tubing transfers heat quicker than plastic tubing...
Using Coils of tubing, rather than straight run tubing will shorten the trench length...
Many Geo-units use coils dropped down a well, rather than trenches...
And,...
I would imagine that Frost depth in your area would be 4' or Less, just go deeper than that...

I Like the idea,... Actually, I've thought of building a Huge fishtank stocked with Local species from the Chaumont river,...
I've also got a Plan to constantly cycle the Chaumont river through the fishtank,...
No filters, just constant water exchange with the bottom of the river...

I'd love to figure out how to put a multi-story fishtank, inside the proposed spiral staircase....
Something like 8' tall, by 2' or 3' diameter...
Oh well,... Still dreamin' on that 1....

 

[Splat]

Re: Crazy Aquarium Geo-thermal idea

Marlboro, you said a heat exchanger, are you talking to cool the water in the sump? I wass thinking just pumping the water from the sump through the piping and back into the sump, the cooled water would them be pumped into the aquarium as part of the normal filtering process. Perhaps there's something your seeing here I'm not.

Can I direct bury copper? Could I just use the heavy gauge copper piping and solder it together in the ground? I would imagine copper tubing in a roll would be easier to deal with...

My other concern here is temp controll in the tank. I don't want the heater to be fighting the cool water all the time, so I'm thinking a simple circuit with a temp probe.... When the tank water becomes warm it would turn on the circulation pump, pumping water from the sump thru the geothermal back to the sump, then the normal filtering will take that water and mix it back into the tank to cool its inhabitants. I think using a lower gph circulation pump to the geo thermal should keep the temp fluctuations minimal allowing everything to equalize slowly.

Bill

 

[Ken G]

Re: Crazy Aquarium Geo-thermal idea

You can direct bury type "K" copper. Its what is used for millions of water service branches around the country. For any buried joints I would recommend flared compression fittings rather than soldering. Soldered joints may corrode underground, they may be OK above ground but I don't know if the salt water would cause any corrosion.

 

[marlboro180]

Re: Crazy Aquarium Geo-thermal idea

Marlboro, you said a heat exchanger, are you talking to cool the water in the sump? I wass thinking just pumping the water from the sump through the piping and back into the sump, the cooled water would them be pumped into the aquarium as part of the normal filtering process. Perhaps there's something your seeing here I'm not.

Can I direct bury copper? Could I just use the heavy gauge copper piping and solder it together in the ground? I would imagine copper tubing in a roll would be easier to deal with...

My other concern here is temp controll in the tank. I don't want the heater to be fighting the cool water all the time, so I'm thinking a simple circuit with a temp probe.... When the tank water becomes warm it would turn on the circulation pump, pumping water from the sump thru the geothermal back to the sump, then the normal filtering will take that water and mix it back into the tank to cool its inhabitants. I think using a lower gph circulation pump to the geo thermal should keep the temp fluctuations minimal allowing everything to equalize slowly.

Bill

I guess I was thinking a multi-plate heat exchanger to keep the sump water segregated from your aquarium, eliminating the need for it to be filtered. Maybe I am missing something though....

As for the copper pipe, flexible copper K wall is fine to direct bury.I would not make underground connections. Backfill w/ CLST (controlled low strength material) for good heat transfer. Or low-tech water compaction with site material.
Or you could use high density poly pipe as is commonly used in geothermal apps., but they normally backfill with a bentonite to maximize heat transfer.

As for a temp . control, how about a strap-on or well type aquastat to control the pump(s)?

 

[j_martin]

Re: Crazy Aquarium Geo-thermal idea

How much cooling are we talking? What's the capacity of your homemade cooler in BTUH or tons?

I cool my entire house with about 2 gallons a minute of well water running through a coil in the plenum of the furnace. The spent water goes out to the fire pond.

The same coil heats the house with boiler heated water in the winter time.

John

 

[HVAC Cruiser]

Re: Crazy Aquarium Geo-thermal idea

It can be done very easily, but as j_ said how much cooling? you said you have a home made chiller BTU/ Ton, 1 ton is 12000 BTU. Do you know what your present flow rate through the chiller is and the delta (differential Temp ) your getting?
To give an example a 1 btu is the amount of energy it takes to raise 1 lb of water 1deg in 1 hr, John stated that he is cooling his home with 2gpm if he has a 20 degree delta, inlet to coil being 50deg outlet being 70deg @ 2 gpm he is @ 20,000 btu
Once you figure out your energy requirements its easy to figure the geothermal piping needed.
I would go with what Marlboro said and use a SS heat exchanger to keep it separate as far as tubing, you can use K copper, pex, AL Pex tubing or even there is a new modular polly panel that Viega makes for geothermal
For controls it depends on how critical temperature fluctuation is. you can use a simple aquastat or if you need to maintain a constant something like the
johnson controls A350P giving a 0-10v output to a Grundfos VS pump would be in order.


Regards,
Bill