Heating large tanks with your gas hot water heater. Save 40% on energy cost!

[Leland Foley]

Your tank heating loop would need to connect to your boiler heating loop through a heat exchanger so that there is no chance of contamination.

-Leland

 

[Blue Carbon Reefing]

I have roughly a 1250 Gallon System all connected through multiple tanks. My electric bill has been $500 every month this winter because it has been so cold. I am estimating that it is costing me $100 to $150 a month just to heat my tank with electrical heaters that are running 24 - 7 and never shutting off for more than a few minutes a day. I am definitely looking into doing this as I have two hot water heaters. My house is new so I have no copper lines but very comfortable using Pex lines. My only question would be should I look at a higher size heat exchanger based on my water volume? It appears the 55k BTU one suggested is good up to 4700 Gallons in a swimming pool application. Not sure about what we would be using it for. Any suggestions?

Thank you.

 

[Leland Foley]

You will have to install a recirculation line, if you don’t already have one, with a pump on your water heater and connect it to your farthest away hot water line. You’ll need to install two spring checks in your lines. After that’s installed, you’ll need to install a flat plate heat exchanger in the recirculation line, and connect your pump and coil/heat exchanger from the aquarium to that with a thermostat control on the pump to the heat exchanger. Your water heater is fine, you’re keeping the aquarium at 75, and it’s likely heating to 120 or higher, so it can easily heat that and recover with likely no noticeable difference on your domestic hot water usage.
Make sure to insulate all of your hot water lines and recirculating lines.

-Leland

 

[DBR_Reef]

I have roughly a 1250 Gallon System all connected through multiple tanks. My electric bill has been $500 every month this winter because it has been so cold. I am estimating that it is costing me $100 to $150 a month just to heat my tank with electrical heaters that are running 24 - 7 and never shutting off for more than a few minutes a day. I am definitely looking into doing this as I have two hot water heaters. My house is new so I have no copper lines but very comfortable using Pex lines. My only question would be should I look at a higher size heat exchanger based on my water volume? It appears the 55k BTU one suggested is good up to 4700 Gallons in a swimming pool application. Not sure about what we would be using it for. Any suggestions?

Thank you.

Short answer is no, either of the smallest inline heat exchangers or the titanium coils you put in the sump (from fish street) should provide plenty of heat. Based on the cost you gave you have about 1500w of heaters running constantly? The 55k btu heat exchanger I used can transfer the equivalent of 15,000 watts. If there is a limiting factor it would probably be your hot water heater.

 

[AlexG]

Short answer is no, either of the smallest inline heat exchangers or the titanium coils you put in the sump (from fish street) should provide plenty of heat. Based on the cost you gave you have about 1500w of heaters running constantly? The 55k btu heat exchanger I used can transfer the equivalent of 15,000 watts. If there is a limiting factor it would probably be your hot water heater.

I have roughly a 1250 Gallon System all connected through multiple tanks. My electric bill has been $500 every month this winter because it has been so cold. I am estimating that it is costing me $100 to $150 a month just to heat my tank with electrical heaters that are running 24 - 7 and never shutting off for more than a few minutes a day. I am definitely looking into doing this as I have two hot water heaters. My house is new so I have no copper lines but very comfortable using Pex lines. My only question would be should I look at a higher size heat exchanger based on my water volume? It appears the 55k BTU one suggested is good up to 4700 Gallons in a swimming pool application. Not sure about what we would be using it for. Any suggestions?

Thank you.

I would agree with @DBR_Reef that a larger heat exchanger should not be needed and the limiting factor will be the hot water heater. I am heating 1600 gallons of water and my radiant heating system has only been kicking on 3-4 times a day during the winter and my system is in an unfinished basement. The big thing to ensure is that whatever type of heat exchanger you use that its not overheating the water before it flows back into your displays. Using water flow controls, water heater temperature controls, and proper temperature controller probe placement will help to ensure a gradual heating taking place in your displays so tank inhabitants are not shocked by rapid temperature fluctuations.

 

[Blue Carbon Reefing]

I would agree with @DBR_Reef that a larger heat exchanger should not be needed and the limiting factor will be the hot water heater. I am heating 1600 gallons of water and my radiant heating system has only been kicking on 3-4 times a day during the winter and my system is in an unfinished basement. The big thing to ensure is that whatever type of heat exchanger you use that its not overheating the water before it flows back into your displays. Using water flow controls, water heater temperature controls, and proper temperature controller probe placement will help to ensure a gradual heating taking place in your displays so tank inhabitants are not shocked by rapid temperature fluctuations.

Thank you all. I have seen you @AlexG on the live chats. Next time I am on one with you maybe you can show me how you plumbed yours into your water heater. Unless you have a video or a link to share. I am going through your build thread now to see if you have any pictures in there.

 

[DBR_Reef]

You will have to install a recirculation line, if you don’t already have one, with a pump on your water heater and connect it to your farthest away hot water line. You’ll need to install two spring checks in your lines. After that’s installed, you’ll need to install a flat plate heat exchanger in the recirculation line, and connect your pump and coil/heat exchanger from the aquarium to that with a thermostat control on the pump to the heat exchanger. Your water heater is fine, you’re keeping the aquarium at 75, and it’s likely heating to 120 or higher, so it can easily heat that and recover with likely no noticeable difference on your domestic hot water usage.
Make sure to insulate all of your hot water lines and recirculating lines.

-Leland

Any reason you used the additional plate heat exchanger? IE is it to remove water at pressure from your sump area?

 

[Leland Foley]

Any reason you used the additional plate heat exchanger? IE is it to remove water at pressure from your sump area?

They’re just available everywhere, so that’s what I suggested. You don’t want to have a direct connection to the domestic water and the water being circulated in the sump. If there ever would be a leak or failure in the heating loop, you’d be drinking and bathing in water contaminated with tank water.
The best option, IMO, would be to have Bill Wann build a titanium heat exchanger for you, and circulate it through that.

-Leland

 

[DBR_Reef]

They’re just available everywhere, so that’s what I suggested. You don’t want to have a direct connection to the domestic water and the water being circulated in the sump. If there ever would be a leak or failure in the heating loop, you’d be drinking and bathing in water contaminated with tank water.
The best option, IMO, would be to have Bill Wann build a titanium heat exchanger for you, and circulate it through that.

-Leland

Do you use apex as the heat exchanger for the sump?

 

[Leland Foley]

Do you use apex as the heat exchanger for the sump?

No, you could use an Apex to open a zone valve or turn on a pump that would start circulating water through the heat exchanger. You can also use an aquastat or other thermostat designed for hydronic systems.

-Leland

 

[DBR_Reef]

No, you could use an Apex to open a zone valve or turn on a pump that would start circulating water through the heat exchanger. You can also use an aquastat or other thermostat designed for hydronic systems.

-Leland

Sorry, that was supposed to say pex, not apex

 

[Leland Foley]

Sorry, that was supposed to say pex, not apex

You could use pex, but Bill Wann pointed out to me, that it doesn’t transfer heat very well at all. There are titanium heat exchangers made for home beer brewing that can be used instead, that just drop in and have male threads on them to attach any water line you like. He also makes great heat exchangers for very fair prices.

-Leland

 

[DBR_Reef]

You could use pex, but Bill Wann pointed out to me, that it doesn’t transfer heat very well at all. There are titanium heat exchangers made for home beer brewing that can be used instead, that just drop in and have male threads on them to attach any water line you like. He also makes great heat exchangers for very fair prices.

-Leland

Yeah, I obviously use titanium, I was just wondering if you were worried about leaks because you were using pex (which I would think has a greater chance of leaking).

 

[Blue Carbon Reefing]

Yeah, I obviously use titanium, I was just wondering if you were worried about leaks because you were using pex (which I would think has a greater chance of leaking).

I can say I have Pex plumbing throughout my entire house and have never had a single leak. It was new construction but I have been there over 2 years now. I can definitely attest that they are not very good at insulating. The cold water lines definitely collect moisture in the summer when the humidity is higher. That is easily solvable by putting foam insulation around them which can be found at any hardware store.

 

[BZOFIQ]

Hello guys, where can one buy different Ti coils?

 

[DBR_Reef]

Hello guys, where can one buy different Ti coils?

you can buy the inline on ebay, or the coil off fish street, or apparently Bill Wann
www.fish-street.com/aquarium_titanium_evaporator

 

[Blue Carbon Reefing]

I am looking for a grundfos recirculation pump on EBAY. Everything I see is around $250 or higher with a timer on it which I assuming is not needed. Can anyone find a good link for a quality re-circulation pump that isn't a Chinese knockoff?

 

[AlexG]

I am looking for a grundfos recirculation pump on EBAY. Everything I see is around $250 or higher with a timer on it which I assuming is not needed. Can anyone find a good link for a quality re-circulation pump that isn't a Chinese knockoff?

I got my Grundfos pump from Supply House

 

[DBR_Reef]

I am looking for a grundfos recirculation pump on EBAY. Everything I see is around $250 or higher with a timer on it which I assuming is not needed. Can anyone find a good link for a quality re-circulation pump that isn't a Chinese knockoff?

https://www.ebay.com/itm/Watts-Hot-...In-Timer-Water-Pump-500800-Used/132498327622?
https://www.ebay.com/itm/Watts-Hot-...uilt-In-Timer-Water-Pump-500800/132498506224?
https://www.ebay.com/itm/Grundfos-U...ot-Water-Recirculation-Pump-3-4/112791501685?

 

[Leland Foley]

Grundfos do not have the best track record in the plumbing world. There are many brands available through any local plumbing supply house. Bell & Gossett and Taco are big names with good reputations. Also, any brand of reliable recirculation pump will not be cheap.

-Leland