DHW coil testing
- oeespo
- Member
- Posts: 76
- Joined: Tue. Nov. 24, 2015 10:12 am
- Hand Fed Coal Furnace: Hitzer 82FA
- Coal Size/Type: Anthracite NUT
Finally just completed installing my DHW coil in my in Hitzer 82FA hand fed hot air furnace. Getting it hot after chasing some leaks. anyone have any experience with thermosiphon? How do I tell how good or bad its working? Top pipe 'hot side' of the coil is too hot to hold your hand on. The cold side from the bottom of the tank is pretty cool. None of the lines are insulated and i'm at the limit on distance about 10' horizontal. 14lf of pipe run.
- Lightning
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- Location: Olean, NY
- Stoker Coal Boiler: Modified AA 130
- Coal Size/Type: Pea Size - Anthracite
Mine has about a 25 degree differential between the cold side and the hot side but that's because the tank is close and I used 3/4 inch copper for less flow friction.
Here's a diagram of my hot water system.
"Pardon the crudity I didn't have time to build it to scale or paint it.."
In coal preheat mode
Valve 1 and 3 are open, valve 2 is closed.
Valve 2 stops flow directly to the electric tank and forces it to go thru the temper tank.
During the off season
Valve 1 and 3 are closed, valve 2 is open
Valve 1 and 3 isolate the tank during the summer so no cold water gets to the coil while I'm not burning coal.
Valve 2 allows cold water to flow directly to the electric tank.
Attachments
- Lightning
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- Stoker Coal Boiler: Modified AA 130
- Coal Size/Type: Pea Size - Anthracite
I have two tanks in series, one is looped thru the coal furnace, the other is electric and powered on. The first tank sends preheated water to the electric tank.
Are you using a single tank?
Are you using a single tank?
- Lightning
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- Stoker Coal Boiler: Modified AA 130
- Coal Size/Type: Pea Size - Anthracite
Quite honestly, that looks like a lot of distance for a thermo siphon to work out well. I'm guessing the turn over will be pretty slow and you'll have a small volume of water at the top of your tank that will be dangerously hot at the spigot.
Can you hear any boiling in the coil?
Can you hear any boiling in the coil?
- oeespo
- Member
- Posts: 76
- Joined: Tue. Nov. 24, 2015 10:12 am
- Hand Fed Coal Furnace: Hitzer 82FA
- Coal Size/Type: Anthracite NUT
Running single tnk. I heard or read 10' max for thermosiphon. I'm 14ft 'of pipe' with the hz runs. I just ran downstairs and measured the hot pipe measures 9'-3" the cold measures 9'-1" to the elbow that go to each appliance.
Think it will work?
and other than turning the tank breaker off, how do i tell if its working well. thanks
Think it will work?
and other than turning the tank breaker off, how do i tell if its working well. thanks
- Lightning
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- Joined: Wed. Nov. 16, 2011 9:51 am
- Location: Olean, NY
- Stoker Coal Boiler: Modified AA 130
- Coal Size/Type: Pea Size - Anthracite
Can you secure a meat thermometer to the hot pipe with some electric tape to monitor with?
As I mentioned above, it looks kind of long to me. I don't know how well it will work.
As I mentioned above, it looks kind of long to me. I don't know how well it will work.
- McGiever
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- Location: Junction of PA-OH-WV
- Stoker Coal Boiler: AXEMAN-ANDERSON 130 "1959"
- Hand Fed Coal Boiler: BUCKET A DAY water heater
- Hand Fed Coal Stove: Warm Morning 414A
- Coal Size/Type: PEA,NUT,STOVE /ANTHRACITE
- Other Heating: Ground Source Heat Pump and some Solar
- McGiever
- Member
- Posts: 10130
- Joined: Sun. May. 02, 2010 11:26 pm
- Location: Junction of PA-OH-WV
- Stoker Coal Boiler: AXEMAN-ANDERSON 130 "1959"
- Hand Fed Coal Boiler: BUCKET A DAY water heater
- Hand Fed Coal Stove: Warm Morning 414A
- Coal Size/Type: PEA,NUT,STOVE /ANTHRACITE
- Other Heating: Ground Source Heat Pump and some Solar
The degrees differential can be an indicator. The lower the differential the better the flow is.
- oeespo
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- Hand Fed Coal Furnace: Hitzer 82FA
- Coal Size/Type: Anthracite NUT
I have not heard any boiling in the coil yet. I have kids so your comment about small amt of dangerously hot water at spigot is most concerning to me. I didn't put a tempering valve inLightning wrote: ↑Sat. Dec. 30, 2017 8:33 pmQuite honestly, that looks like a lot of distance for a thermo siphon to work out well. I'm guessing the turn over will be pretty slow and you'll have a small volume of water at the top of your tank that will be dangerously hot at the spigot.
Can you hear any boiling in the coil?