Hot water hook-up for geo-thermal install

[mongo3037]

I am in the process of having a Waterfurnace EO60 5 ton installed in our new house. I had previously read on this forum that it is a good idea to have a second water tank (without electric) connected tothe desuperheater for additional water storage capacity. Any comments as to feasability of this setup and specifics, ie; tank size, plumbing configuration, etc, would be appreciated. Also, any other tips or suggestions on installation or setup are welcomed. Tks John

[pyropaul]

We have a system which doesn't have an extra buffer tank and it works well. The tank is gas heated and the gas consumption goes down to near zero in winter. However, we're only two and don't use huge amounts of hot water. The best configuration is to use an unconnected electric tank and connect the cold water input to this first unheated tank. The de-superheater heat exchanger then goes into the bottom of this tank. Connect the output (top) of the buffer tank to the cold water inlet of your normal (heated) tank. As you take water out of your regular tank, the pre-heated water from the buffer tank will enter the bottom of your normal tank. Depending how much water you use and how cold a climate you live in, you could save over 50% in your hot water costs and soon repay the additional cost of the buffer tank. In our case, there wasn't space to install a buffer so we just put the desuperheater loop into the bottom of the regular (gas) tank and it works well for us.

Hope this helps,

Paul.

p.s. gas consumption in our system also goes down during air conditioning season too

[tecman]

All of the units I install use a second 50 gallon electric HW heater. The electric is not connected. It is connected to the cold water line in series with the main HW heater. The desuperheater loop should draw out of the bottom, where the drain valve is connected, and return to a "T" in the cold water inlet.

Having a buffer tank is a much better solution, since trying to use the normal HW heater, especially a gas model, may not have enough delta T to work well. With the buffer tank you will heat preheated water. Any BTU's and temp rise are heating that the main tank does not need to do.

paul

[danf58]

I'm surprised there's any value to installing one w/o the second tank. In fact, I'd have thought it mildy bad. I'm sure the second tank will pay for itself, and rather quickly so it seems a no brainer to me..

I'm using an E60 w/a 75 gallon has, not hooked up, feeding a 50 gallon gas, hooked up, feeding another 50 gallon gas, hooked up. I'm fairly confident I can't run out of hot water, and I've certainly tried..

[mongo3037]

After many months, we are finally about ready to fire up the geo-thermal and hook-up the hot water and aux storage tank. Thought I would bump my original post to see if there might be any new idas or suggestions for hooking up the unwired second hot water storage tank. Any suggestions are welcomed. Tks John

[frankspinz]

Just moved in to our new house. The Waterfurnace Premier geothemal pump is running fine to keep the house toasty in the cold Canadian winter... the desuperheater is causing me problems however. My installation is like this:

http://img.photobucket.com/albums/v653/frankspinz/Desuperheater2.jpg

- I get hot to warm water at the cold water faucet for a few seconds when turned on ( cold water supply comes from "T" above "cold water in" .
- I get warm water from the hot water faucet at best and cold when the furnace blower is running. (feels like the water is coming directly from the preheat tank) - household hot water is supplied from the: "hot water out" line .
- checked the pipes and all is like the diagram.
- turned off the dwh pump and closed the valves to the preheat tank and the problem is solved: cold water to cold faucet and hot (very hot) to hot water faucet ...

I'm hoping to have a few clues before calling my installer. Any help will be appreciated !!!

[pyropaul]

.

[tecman]

I have done a number of these, and the only difference is that we pull the cold from the bottom of the tank to the HP and return to the cold inlet of the tank. Reverse flow from what you show.

What you describe seems almost impossible. Is the main HW tank powered up ? It should be. You are basically feeding warm pre-heated water into your HW heater to reduce the work that it does. No way should the HOT water temp be any different with or w/o the desuperhreater running. The main tank should bring it up to nominal hot temp. As far as warm water from the cold tap, again there should be no reverse flow from the preheat tank line to the cold water. Something is screwed up in the piping somewhere.

paul

[frankspinz]

I'm thinking maybe the plumber reversed the pipe connections at the HW tank or the preheat tank. There are no markings on the water tanks I can use to verify which pipe should be plugged in where !?:confused:

Model: http://www.giantinc.com/english/products/residential/electric-standard.htm

I've looked at the documentation and the only way I've seen to differentiate the hot water outlet from the cold water inlet is that the outlet should be on the same side as the drain valve .

[tecman]

Facing the tank (heating elements directly in from of you), normally then cold is to the right, hot to the left. It should have an H and C in the metal near the fittings.

paul

[frankspinz]

Facing the tank (heating elements directly in from of you), normally then cold is to the right, hot to the left. It should have an H and C in the metal near the fittings.

paul

Thanks,:cool: if that is the case the plumber inverted the preheat tank hook-up. I'll have him reverse the connections in the hopes it solves this issue for me ! I'll post the outcome ...

[geodude]

We have a system which doesn't have an extra buffer tank and it works well. The tank is gas heated and the gas consumption goes down to near zero in winter. However, we're only two and don't use huge amounts of hot water. The best configuration is to use an unconnected electric tank and connect the cold water input to this first unheated tank. The de-superheater heat exchanger then goes into the bottom of this tank. Connect the output (top) of the buffer tank to the cold water inlet of your normal (heated) tank. As you take water out of your regular tank, the pre-heated water from the buffer tank will enter the bottom of your normal tank. Depending how much water you use and how cold a climate you live in, you could save over 50% in your hot water costs and soon repay the additional cost of the buffer tank. In our case, there wasn't space to install a buffer so we just put the desuperheater loop into the bottom of the regular (gas) tank and it works well for us.

Hope this helps,

Paul.

p.s. gas consumption in our system also goes down during air conditioning season too

That is not is not a recommended install practice by waterfurnace. The reason is IF the burner lit up,the intake of water from the dip tube will be heated from the burner and possibly turn off the desuperheater pump. When the pump limit sensor sees 120 degrees fahrenheit, it will turn off the pump. Look at the installation instructions. Fossil fueled single tank systems are not recommended.

[geodude]

Just moved in to our new house. The Waterfurnace Premier geothemal pump is running fine to keep the house toasty in the cold Canadian winter... the desuperheater is causing me problems however. My installation is like this:

http://img.photobucket.com/albums/v653/frankspinz/Desuperheater2.jpg

- I get hot to warm water at the cold water faucet for a few seconds when turned on ( cold water supply comes from "T" above "cold water in" .
- I get warm water from the hot water faucet at best and cold when the furnace blower is running. (feels like the water is coming directly from the preheat tank) - household hot water is supplied from the: "hot water out" line .
- checked the pipes and all is like the diagram.
- turned off the dwh pump and closed the valves to the preheat tank and the problem is solved: cold water to cold faucet and hot (very hot) to hot water faucet ...

I'm hoping to have a few clues before calling my installer. Any help will be appreciated !!!

How old is your unit? There were some units about 6-7 years ago that went out with the DHW IN and DHW out stickers put on backwards. This was on the premier units.

[geodude]

I'm thinking maybe the plumber reversed the pipe connections at the HW tank or the preheat tank. There are no markings on the water tanks I can use to verify which pipe should be plugged in where !?:confused:

Model: http://www.giantinc.com/english/products/residential/electric-standard.htm

I've looked at the documentation and the only way I've seen to differentiate the hot water outlet from the cold water inlet is that the outlet should be on the same side as the drain valve .

Can you post a pix of the plumbing from the HP to the tank?

[geodude]

I'm surprised there's any value to installing one w/o the second tank. In fact, I'd have thought it mildy bad. I'm sure the second tank will pay for itself, and rather quickly so it seems a no brainer to me..

I'm using an E60 w/a 75 gallon has, not hooked up, feeding a 50 gallon gas, hooked up, feeding another 50 gallon gas, hooked up. I'm fairly confident I can't run out of hot water, and I've certainly tried..

You will find that an electric tank used as a storage tank is far more efficient then a gas tank. The gas tank waterheater has a hole up the middle of the tank and it will convect air from temperature rise and cool off the tank rather quickly. Use an 80 gallon electric for your storage tank and if you want to go even farther insulate the 80 gallon electric storage tank. It will maximize your efficiency.

[geodude]

Thanks,:cool: if that is the case the plumber inverted the preheat tank hook-up. I'll have him reverse the connections in the hopes it solves this issue for me ! I'll post the outcome ...

Give your plumber a copy of the piping diagram for the desuperheater.

[geodude]

I am in the process of having a Waterfurnace EO60 5 ton installed in our new house. I had previously read on this forum that it is a good idea to have a second water tank (without electric) connected tothe desuperheater for additional water storage capacity. Any comments as to feasability of this setup and specifics, ie; tank size, plumbing configuration, etc, would be appreciated. Also, any other tips or suggestions on installation or setup are welcomed. Tks John

Put in the biggest storage tank you can. We recommend an eighty gallon electric tank, (not wired in )for storage. it is much cheaper to buy then a super store tank. Follow the recommended installation instructions provided by the manufacturer of your heat pump.

[pyropaul]

That is not is not a recommended install practice by waterfurnace. The reason is IF the burner lit up,the intake of water from the dip tube will be heated from the burner and possibly turn off the desuperheater pump. When the pump limit sensor sees 120 degrees fahrenheit, it will turn off the pump. Look at the installation instructions. Fossil fueled single tank systems are not recommended.

We don't have a waterfurnace unit, it's ClimateMaster. I didn't see anything in the manual about not using such a setup with gas hot water tanks. Anyway, it seems to work fine - the gas consumption goes way down in winter. The "dip tube" is a good 8" below the burner anyway so I'm not sure how it would see any hot water. Of course, all that said, it always makes sense to go with the manufacturer's instructions.

Paul in Montreal.

[tecman]

Independent of the brand, adding a second non powered tank piped in-front of the regular hot water heater will maximize the benefit of the geo hot water generator. Using a single tank will work, but the warm to hot water that you are circulating reduces the amount of heat that you can transfer. a separate tank will act as a "tempering" tank to preheat the water to the regular heater. Being at a lower temp reduces the chance that it will get hot enough to shut down (stat in the geo unit). Every BTU you put in the water is a BUT you are not paying for. Besides squeezing out the most heat, a second tank also increases the capacity of warm water available.

Both solutions work, but two tanks is better. Disadvantage is it will cost more to install.

Just a note, ClimateMaster install manuals show both single and double tank hook-ups. In the install manual, it states "If a gas, propane, or oil water heater is used, a second preheat tank must be installed (Figure 15)." Further the manual comments "Typically a single tank...is used to limit installation costs and space. However, a dual tank, as shown in figure 15, is the most efficient system, providing the maximum storage and temperature source water to the HWG."

paul

[geodude]

We don't have a waterfurnace unit, it's ClimateMaster. I didn't see anything in the manual about not using such a setup with gas hot water tanks. Anyway, it seems to work fine - the gas consumption goes way down in winter. The "dip tube" is a good 8" below the burner anyway so I'm not sure how it would see any hot water. Of course, all that said, it always makes sense to go with the manufacturer's instructions.

Paul in Montreal.

Paul, I'm certified in both brands, they both recommened against it. Your full potential of the desuper heater will not be reached. It will work as you have it installed, but not to its full potential.

[frankspinz]

How old is your unit?

The entire instalation is brand new ...

[geodude]

I'm thinking maybe the plumber reversed the pipe connections at the HW tank or the preheat tank. There are no markings on the water tanks I can use to verify which pipe should be plugged in where !?:confused:

Model: http://www.giantinc.com/english/products/residential/electric-standard.htm

I've looked at the documentation and the only way I've seen to differentiate the hot water outlet from the cold water inlet is that the outlet should be on the same side as the drain valve .

We have the same problems with some plumbers in our area. They get confused because it is out of the norm for them. We have a start up tech work with the plumber to make sure the lines to the HP and between the tanks are piped right.

[pyropaul]

Paul, I'm certified in both brands, they both recommened against it. Your full potential of the desuper heater will not be reached. It will work as you have it installed, but not to its full potential.

You're right, we're not getting the full potential but at the time it was installed there wasn't space for the buffer tank (long story). Anyway, in winter, our gas consumption goes down to about Can$1.85 a month (when the weather is cold) so it's hard to see how it could get much less than that for the amount of hot water we're using ;) At that low a consumption, it would take decades to pay back the cost of the buffer tank. One day when there's the time/money/space, I'll put in buffer tanks and hook them up to solar panels - but more to provide a source of auxiliary heat rather than hot water (as we obviously can't be using that much at the moment). I have in mind a mini Drake's Landing ( see http://dlsc.ca for a really neat interseasonal storage system in Alberta using vertical boreholes and arrays of solar collectors).

Paul.

[geodude]

You're right, we're not getting the full potential but at the time it was installed there wasn't space for the buffer tank (long story). Anyway, in winter, our gas consumption goes down to about Can$1.85 a month (when the weather is cold) so it's hard to see how it could get much less than that for the amount of hot water we're using ;) At that low a consumption, it would take decades to pay back the cost of the buffer tank. One day when there's the time/money/space, I'll put in buffer tanks and hook them up to solar panels - but more to provide a source of auxiliary heat rather than hot water (as we obviously can't be using that much at the moment). I have in mind a mini Drake's Landing ( see http://dlsc.ca for a really neat interseasonal storage system in Alberta using vertical boreholes and arrays of solar collectors).

Paul.

It would probably go down a lot more with a buffer tank. If the returning water to the desuper heater is hot (120 deg far.) your pump will shut off. With a buffer tank that possibility is eliminated. You may recognize more energy savings and pay off the buffer tank sooner. The tank can be 40 gallons or more, just get an electric tank ( don't wire it up ) and wrap it up in insulation. Don't use a gas tank, the hole up the middle creates a draft and will cool of the tank rapidly.

[frankspinz]

We have the same problems with some plumbers in our area. They get confused because it is out of the norm for them. We have a start up tech work with the plumber to make sure the lines to the HP and between the tanks are piped right.


I discussed the hookup issue with my plumber. He had indeed inverted the hot & cold piping on the storage tank. The hookup has been corrected and all the mysterious problems have disapeared. We are very pleased ! Thanks everyone for your input ! :D