Thermal loop to existing water heater - efm520

Thermal loop to existing water heater - efm520

PostBy: Joe G On: Sun Nov 03, 2013 4:42 pm

Guys,

As I go about planning to replace my electric baseboard for hot water baseboard I've been wondering if it makes any sense to add my existing 82 gallon electric water heater to the mix via a thermal loop. I'm struggling to figure out the best way to have hot water during the summer months. When my Dad had this running we simply just kept the coal burner going but I wonder if there's a better way.

Any thoughts? Has anyone done this and was it worth while?

Thanks
Joe
Joe G
 
Stove/Furnace Make: EFM
Stove/Furnace Model: DF 520

Re: Thermal loop to existing water heater - efm520

PostBy: Rob R. On: Sun Nov 03, 2013 4:55 pm

Joe, as long as your electric water heater is well insulated (modern ones have spray foam and hold heat really well) I would just use a tankless coil in the EFM...hook it up to preheat the water going to the electric water heater. I did this in my brother's house and it works very well.

One thing to remember, be sure you pipe things so that if you don't want to use the coal boiler the water DOES NOT go through the coil. Running water through the coil in an unfired coal boiler will cause condensation and corrosion in the firebox.
Rob R.
 
Stoker Coal Boiler: EFM DF520
Hand Fed Coal Stove: Hitzer 50-93
Other Heating: Dad's 1953 EFM Highboy

Re: Thermal loop to existing water heater - efm520

PostBy: franpipeman On: Sun Nov 03, 2013 7:18 pm

IF using a indirect hot water heater, i would pipe parallel, in a geyser hot water heat pump in the summer , it also provides dehumidification and the space and provides cooling for approx. 700 watts of operation Heavy and severe demand may require intermittent short term back up like electric resistance heating , but i prefer getting dehumidification and cooling from my summer hot water production rather than additional heat,,,,, call me eccentric.
franpipeman
 
Stoker Coal Boiler: efm 520 stoker fitzgibbons pressure vessel
Hand Fed Coal Stove: harman, russo
Coal Size/Type: rice

Re: Thermal loop to existing water heater - efm520

PostBy: franpipeman On: Sun Nov 03, 2013 7:18 pm

IF using a indirect hot water heater, i would pipe parallel, in a geyser hot water heat pump in the summer , it also provides dehumidification and the space and provides cooling for approx. 700 watts of operation Heavy and severe demand may require intermittent short term back up like electric resistance heating , but i prefer getting dehumidification and cooling from my summer hot water production rather than additional heat,,,,, call me eccentric.
franpipeman
 
Stoker Coal Boiler: efm 520 stoker fitzgibbons pressure vessel
Hand Fed Coal Stove: harman, russo
Coal Size/Type: rice

Re: Thermal loop to existing water heater - efm520

PostBy: Mark (PA) On: Sun Nov 03, 2013 8:10 pm

my Hot water tank is plumbed as Rob Mentioned above.

About 4 months a year i do not usually run my coal boiler. sometimes I do. Just depends on how much coal I have left etc.

But bottom line this setup works fine for me. Just so you can shut off the Coil when not in use as mentioned.
Mark (PA)
 
Stove/Furnace Make: 1953 EFM SF-520 High Boy
Stove/Furnace Model: Fitzgibbon Boiler

Re: Thermal loop to existing water heater - efm520

PostBy: Joe G On: Mon Nov 04, 2013 10:01 am

Rob R. wrote:Joe, as long as your electric water heater is well insulated (modern ones have spray foam and hold heat really well) I would just use a tankless coil in the EFM...hook it up to preheat the water going to the electric water heater. I did this in my brother's house and it works very well.

One thing to remember, be sure you pipe things so that if you don't want to use the coal boiler the water DOES NOT go through the coil. Running water through the coil in an unfired coal boiler will cause condensation and corrosion in the firebox.



Rob, since I'm nothing more than an advanced DIYer, can you or anyone else, help me understand what a tankless coil is and how it connects to the EFM? Maybe a picture would be enough.
I happen to have a very new hot water heater, so you're correct, it's very well insulated
Regards,
Joe
Joe G
 
Stove/Furnace Make: EFM
Stove/Furnace Model: DF 520

Re: Thermal loop to existing water heater - efm520

PostBy: kstills On: Mon Nov 04, 2013 1:20 pm

Rob R. wrote:Joe, as long as your electric water heater is well insulated (modern ones have spray foam and hold heat really well) I would just use a tankless coil in the EFM...hook it up to preheat the water going to the electric water heater. I did this in my brother's house and it works very well.

One thing to remember, be sure you pipe things so that if you don't want to use the coal boiler the water DOES NOT go through the coil. Running water through the coil in an unfired coal boiler will cause condensation and corrosion in the firebox.


How did you do that?
kstills
 
Stoker Coal Boiler: WL 110
Stove/Furnace Make: Leisure Line

Re: Thermal loop to existing water heater - efm520

PostBy: Rob R. On: Mon Nov 04, 2013 2:00 pm

Joe G wrote:Rob, since I'm nothing more than an advanced DIYer, can you or anyone else, help me understand what a tankless coil is and how it connects to the EFM? Maybe a picture would be enough.


A tankless coil is a heat exchanger for domestic hot water. Basically it is a bundle of copper tubing that bolts into the boiler with a gasket, the domestic water flows through it and gets warmed by the hot boiler water surrounding the copper tubing. Here is a link that shows what the various coils look like for an EFM: Pictorial: DF520 Domestic water coils w/part numbers

kstills wrote:How did you do that?


You just leave a bypass between the connection points. Picture a straight piece of pipe going to the water heater. Cut into the pipe, install a tee, then a ball valve, then another tee. The two tee's connect to the coil in the boiler, close the valve between them to force the water through the coil...open it and valve off the coil (always put ball valves and unions prior to the coil) to protect the boiler when not in use.
Rob R.
 
Stoker Coal Boiler: EFM DF520
Hand Fed Coal Stove: Hitzer 50-93
Other Heating: Dad's 1953 EFM Highboy

Re: Thermal loop to existing water heater - efm520

PostBy: kstills On: Mon Nov 04, 2013 3:26 pm

Rob R. wrote:
Joe G wrote:Rob, since I'm nothing more than an advanced DIYer, can you or anyone else, help me understand what a tankless coil is and how it connects to the EFM? Maybe a picture would be enough.


A tankless coil is a heat exchanger for domestic hot water. Basically it is a bundle of copper tubing that bolts into the boiler with a gasket, the domestic water flows through it and gets warmed by the hot boiler water surrounding the copper tubing. Here is a link that shows what the various coils look like for an EFM: Pictorial: DF520 Domestic water coils w/part numbers

kstills wrote:How did you do that?


You just leave a bypass between the connection points. Picture a straight piece of pipe going to the water heater. Cut into the pipe, install a tee, then a ball valve, then another tee. The two tee's connect to the coil in the boiler, close the valve between them to force the water through the coil...open it and valve off the coil (always put ball valves and unions prior to the coil) to protect the boiler when not in use.


Ah, crap. You used a water heater, I'm using an indirect. Different setup.
kstills
 
Stoker Coal Boiler: WL 110
Stove/Furnace Make: Leisure Line