# Geo Thermal Heating



## 3KP (Jun 19, 2008)

I have a builder that is building a house and wanting to use Geo Thermal. I have never had to do this before. I thought it was only for heating and cooling the house. So he asked me what W/H am I going to put in? He said he was going to put in 2 Envision systems seer 30 to equal 5 tons. Does Geo run through the W/H? doesn't sound efficent to me if it does.??

Sorry something new and would like to learn!


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## user2090 (Sep 26, 2009)

You want to get with a wholesaler on the specs for the job. 

In my experience. A typical geo has two water heaters. You pipe the De-Super heater into the first one, which then feeds into the next one, which is actually wired for heating. 

The reason why. In the cooling season, the extra B.T.U's are dumped into the heater which then feeds the house with hot water, which keeps the wired heater from running. This is the most efficient way of piping them in, to my knowledge.


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## Master Mark (Aug 14, 2009)

*Best advice here*

If it were me, I would steer clear of provideing any of the materials on one of those deals....or you could end up married to those tanks for 10 years.... 

Let the* BUILDER* provide the brand of heaters for *you *to hook up to *your plumbing system....* the longer the warranty on the tanks the better...

Recently , I have been dealing with a couple of Bradford white electric heaters that kept leaking .... the fellow finally tore them out and installed marathons...

he has gone through 2 sets of 50 electrics in the past 4 years,, for whatever reason. the get thermal seems to eat them up...


... these were the second set, and last spring I had to change them out and
install 2 fiberglass Rheem marathons...I hope that those last longer than these


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## Protech (Sep 22, 2008)

Why just in the cooling season? During the heating season the heat may not be free waste heat but it's still between 4-8 times cheaper than electric resistance heating. I'd pipe the tanks in series and pull all of the elements out except the last one. That way you will almost never use electric resistance heating and depend mostly on the highly efficient geoheat pump.

Pull the t/p valve and install dip tubes in both t/p ports. The first in heater should have a standard dip tube with the anti-siphon hole at the top welded shut. The last out heater should have a dip tube installed with the same anti-siphon hole welded shut AND the end must be twisted shut. Drill baffle holes on the sides of the tube about 12" below the thermostat height. Both outlet ports will need a brass tee with a close nipple installed. Install an extra long shanked t/p valve in the top leg of the tees and use the middle leg as your outlet port. The desuperheater should pull from the dip tube with the open end and pump back into the baffled dip tube.

I agree with master mark, Some rheem marathons would be an ideal choice for this situation as it will be low temperature. The lack of anodes helps out because there won't be any large chunks of magnesium or aluminum salts falling to the bottom of the tanks to clog the desuperheater heat exchanger. Periodic draining of the boiler scale should be easy as those flakes tend to be smaller than the super clogging anode salts.

Protech's green plumbing tip of the day :thumbsup:



Indie said:


> You want to get with a wholesaler on the specs for the job.
> 
> In my experience. A typical geo has two water heaters. You pipe the De-Super heater into the first one, which then feeds into the next one, which is actually wired for heating.
> 
> The reason why. *In the cooling season*, the extra B.T.U's are dumped into the heater which then feeds the house with hot water, which keeps the wired heater from running. This is the most efficient way of piping them in, to my knowledge.



Addition: This method only works for tanks with the T/P port on the top (like the marathon). Additionally, If you want to go cheap and easy, American's electric tanks have an optional T/P connection on the the side as well. If you move the T/p valve to the side port, you now have an extra port on the top (the original T/P port) to connect your suction and return lines for the desuperheater. No need for the brass tees and long shanked T/P valves. :thumbsup:


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## Protech (Sep 22, 2008)

Also Indie, while your picture is not technically wrong, it will operate far less efficiantly than the above method.


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## 3KP (Jun 19, 2008)

I was thinking of using a tankless and a storage tank but might just say It's not my thing might have your heating guy do all of the geo set up?? Just never done it so little nervous about it. 

I have a diagram showing a storage tank with cold n hot into a mixing valve then to a tankless unit? That is if I go with a tankless.. So basically I remove the element, anode rod, and cap of the 1 of the ports on top of the heater.


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## Master Mark (Aug 14, 2009)

*its their job*

honestly 3pk just stay out of it....play dumb...

protect yourelf from delaing with the problems
with heating and cooling... let the hvac guy deal 
with it.. 

Unless you are willing to warrnty the hvac
part of the deal and dig the fuc/ing well 
just let the geo thermal guys 
beat their braines out.

stick with the plumbing and let 
the hvac guys have all the glory..


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## luigi15 (Jan 12, 2011)

you need a 2 hwt system because the geothermal doesn't supply enough hot water for your needs it's basically just a pre-heat help to reduce the cost of heating all your hot water.

:thumbsup:


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## Protech (Sep 22, 2008)

Most geothermal desuperheaters will heat water to 130F. That's plenty hot. 

The unit can be made to run simply to heat water as well. This can be done even if there is no need to run the HVAC system.


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## luigi15 (Jan 12, 2011)

it's not that efficiient thogh is it Protech?
\


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## Protech (Sep 22, 2008)

No, but it's more efficient than the electric resistance element that would replace it. :whistling2:



luigi15 said:


> it's not that efficiient thogh is it Protech?
> \


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