Geothermal cooling idea

[Scuba_Dave]

So, with the garage foundation digging starting soon, I need to figure out a cooling method that I want to install
I'm thinking of buying one of these & having it buried in the garage
300g, 6' 8" high by about 3' across
water would enter the top, and be drawn from the bottom

Anyone know of a local supplier?

 

[MarkO]

I think the theory works!
On a similar note, I noticed a recent significant drop in my elec. bill this past month. Only thing I could attribute it to is the elec. hot water heater. Water source is the Merrimack, so very cold in winter. So maybe install a pre-tank warmed by ambient room temp.

 

[this is me]

Wouldnt you have to run a lot of heaters to keep it warm in the winter time?

 

[Scuba_Dave]

Why would you use a cooler in the winter

This is only for summer use - specifically for cooling

 

[naturebatslast]

What about a similiar setup as a heat pump. Granted you would have to dig deeper.

 

[this is me]

Why would you use a cooler in the winter

This is only for summer use - specifically for cooling

didnt know you can disconnect the system. I wasnt thinking.

 

[marco67]

I think this is likely a great solution for a smaller system, my concern on a larger system would be the ability of the drum to transfer heat. With relatively small surface area (or water touching the sides) compared to the water volume and low water flow, I fear the heat transfer in the barrel would be to slow to keep up with the daytime increase in tank temp.

 

[Kiah]

I agree with Marco. You are going to have a conflicting system. Water is unique in it's ability to hold heat - a wonderful thing for our aquariums. An isolated buried tank would eventually be about 50 D. Your tank is 80.

Might be better to run a lot of small diameter line through the tank and use the stability of the water to transfer to the water running through the lines. You could calculate the theorectical length of line and flow required for various temp differeneces.

 

[Greg Hiller]

Dave,

If you are going to be running tank water in and out you are going to get growth of stuff in the tank, and also settling of detritus in the tank. Each year when you shut the tank off all that stuff is going to die. Next year how are you going to clean that stuff out if the tank is completely buried?

Also, consider carefully the hydralics of your set up. This tank is going to be the most efficient at cooling when it is full. If you are going to be pumping water to it and there is any air entrained in the water, it is possible that the tank will slowly empty of water as the air separates from the water. If instead of pumping to the tank you are going to be allowing water to drain from an overflow, then you will need to figure a way to vent the system. Otherwise it will very quickly fill with air and your overflow may stop working all together.

I agree in general with Marc about the cooling, it is going to be dependent on the surface area of the tank, and also the heat transfer is going to have to deal with the resistance to flow though the walls of the tank. I really don't have a good feel whether for the size of reef tank you are using this on whether it will be overkill, or not enough.

 

[Scuba_Dave]

The tanks have a man hole cover for cleaning, the cover would be even with the cement floor - or slightly raised
It would also have a vent stack to allow air to escape
Water would be draining to the reservoir, pumped back to system
Maybe a small amount draining all the time - then a larger volume pump kicks on when the controller calls for cooling.

Water transfer would only occur when cooling was needed
At night it would shut off via a controller

I have 100g in the basement keeping a 125g tank cool for the majority of the summer with (3) 250w bulbs running. My basement stays just under 70 most of the summer - thats running a 1400gph pump - constant changeover - not much time to cool.
I think 300g of water at 55 would be a much better solution - no?

I meant to add it would be disconnected in the winter

I have more faith in this system then burying tubing in the garage floor - which could clog. Switching to coiled tubing in this resorvoir is an alternate solution at some point

I'm really looking for a supplier at this point...........

 

[NateHanson]

How much do those cost Dave?

Also, if it's going to be tank water in there, won't it be a horrible stinky mess come spring time? I know I didn't run a closed loop for a couple months, and when I opened it up to clean it, the water was extremely stinky. Sulphery smelling. I imagine that would be very bad for a reef to get 600g of that pumped into the tank on the first warm day.

To avoid it you could do a 600g water change every spring, but that's $150 of salt. That'll seriously cut into any energy savings.

 

[sw300galma]

better would be to install like a radiant flooring system only in the concrete...would transfer the heat better.

 

[Scuba_Dave]

I'm passing on the radiant floor idea. In my case they will be mechanically compacting the fill they bring in. I can just imagine what that will do to thin wall tubing

The tanks go for as low as $200, shipping is $100
Hence the need to find a local supply
The tank would be shut off & pumped dry in the fall
Spring time it would be filled w/NSW

 

[Greg Hiller]

Dave,

Sounds like a plan. As long as you can clean it it should not be a big deal. If you want to keep it from going anaerobic at any time you could just toss in an airstone running off a Luft pump. These pumps only use maybe 8 W to run.

 

[Scuba_Dave]

For the price it's worth a try. Worst case I use it to store NSW that I will collect, or for RO/DI waste water for the gardens

Best case is it works very well & eliminates the need for a chiller to run in all but very hot weather. I am planning on a chiller for the big tank - as a security/safety measure

If it doesn't work as planned I can try the coiled tubing inside the resorvoir
Or - I can rent a back hoe & bury tubing after the garage is in
They won't be compacting the soil on the outside of the garage - so I am considering tubing out side the garage
But I think I'd rather just sink a 1200g tank outside rather then doing that

 

[Greg Hiller]

Those are pretty good prices on those tanks. There's no question you will get some decent cooling by burying a tank that size.