Best Way to Do DHW

A Coal stoker furnace or stove controls most operations including automatically feeding the coal. They are quite similar to any conventional oil and gas units and easily operated for extended periods of time. They commonly use rice coal but may use larger sizes like buckwheat. They can be used as primary heat, supplementary heat or have a dual set up with your existing oil/gas furnace.
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Rick 386
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Posts: 2474
Joined: Mon. Jan. 28, 2008 4:26 pm
Stoker Coal Boiler: AA 260 heating both sides of twin farmhouse
Hot Air Coal Stoker Stove: LL Hyfire II w/ coaltrol in garage
Coal Size/Type: Pea in AA 260, Rice in LL Hyfire II
Other Heating: Gas fired infared at work
Location: Royersford, Pa
Contact:

Post Wed. Nov. 06, 2013 10:33 pm

We have kept our AA 260 burning for 6-7 maybe more years in a row now.

Initially we used to just use it for the heating season by starting it around thanksgiving and turning it off near memorial day. Initially my father in law just used the cold oil boiler as the tempering valve. We would always warn everyone when we switched to coal due to the higher temps.

Finally I installed a tempering valve on the coal boiler coil and actually the oil heated water would be hotter.

We have never run out of hot water when on the coal burner. sometimes it may not be as hot and require adjusting the shower control more to the hot side, but all in all, we are happy with just using the coil direct to the hot water lines in the basement. No tank, no buffering, nothing.

Rick
Master of "Trial and Error."


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Rob R.
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Posts: 11367
Joined: Fri. Dec. 28, 2007 4:26 pm
Stoker Coal Boiler: EFM DF520
Hand Fed Coal Stove: Hitzer 50-93
Coal Size/Type: Lehigh Rice
Other Heating: Dad's 1953 EFM Highboy
Location: Chazy, NY

Post Wed. Nov. 06, 2013 11:05 pm

You indicated that your DHW load is average, and you are considering an EFM or AA...so I think a tankless coil with tempering valve would work fine for you. When possible, I do like being able to send the heated water from a coil into an electric hot water heater. Modern water heaters are well insulated, offer some buffer capacity, and it is really nice to let the water heater pick up the load when it is time to service the boiler. In the event you forget to turn the boiler back on after service, your other half will still get a warm shower.

Pacowy
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Posts: 2751
Joined: Tue. Sep. 04, 2007 10:14 pm
Stoker Coal Boiler: H.B. Smith 350 Mills boiler/EFM 85R stoker
Coal Size/Type: Buckwheat/anthracite
Location: Dalton, MA

Post Wed. Nov. 06, 2013 11:34 pm

Rob R. wrote:In the event you forget to turn the boiler back on after service, your other half will still get a warm shower.
Does Rob know this is important because he is a whiz on coal and boiler stuff and a nice guy, or as the result of a harrowing personal experience? :gee: :lol:

Mike

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Rob R.
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Posts: 11367
Joined: Fri. Dec. 28, 2007 4:26 pm
Stoker Coal Boiler: EFM DF520
Hand Fed Coal Stove: Hitzer 50-93
Coal Size/Type: Lehigh Rice
Other Heating: Dad's 1953 EFM Highboy
Location: Chazy, NY

Post Thu. Nov. 07, 2013 7:56 am

Pacowy wrote:
Rob R. wrote:In the event you forget to turn the boiler back on after service, your other half will still get a warm shower.
Does Rob know this is important because he is a whiz on coal and boiler stuff and a nice guy, or as the result of a harrowing personal experience? :gee: :lol:

Mike
2 out of 3.

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Sting
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Posts: 2967
Joined: Mon. Feb. 25, 2008 4:24 pm
Other Heating: OBSO Lennox Pulse "Air Scorcher" burning NG
Location: Lower Fox Valley = Wisconsin

Post Thu. Nov. 07, 2013 8:18 am

SMITTY wrote:I'm hoping Sting will chime in again. That avatar is absolutely WONDERFUL ... :love: :drool: toothy
OK - this is for you pal!
Pacowy wrote:
Point taken, but IMO overdramaticized.
Mike
IMO -- Who cares about IMO - I only care about "What you KNOW- not what you "THINK"

There is no possible way to be "over-dramatic or Melodramatic or stupid dramatic" in regard to the damages of DWH scalding

Stop and consider the possibility of skin damage to a young child -- even the "DRAMA" of death before you discount this warning
When you turn your boiler on -Does it return the favor?
I have finally lost my mind. Don't bother to return it. It wasn't working properly anyway!

Pacowy
Member
Posts: 2751
Joined: Tue. Sep. 04, 2007 10:14 pm
Stoker Coal Boiler: H.B. Smith 350 Mills boiler/EFM 85R stoker
Coal Size/Type: Buckwheat/anthracite
Location: Dalton, MA

Post Thu. Nov. 07, 2013 10:16 am

My point was only that the remedy for this potential problem is known and commonly used; maybe even required by code (?). When you buy a car there is no doubt it could injure or kill people if it doesn't have functioning seatbelts, or if you expose a youngster to airbag deployment. The fact that you may need to use proper and effective safety equipment and procedures doesn't seem like a reasonable basis for ruling out or downgrading the entire option.

Mike

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Townsend
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Posts: 567
Joined: Tue. Nov. 21, 2006 7:38 pm
Stoker Coal Boiler: Axeman Anderson 260
Coal Size/Type: Pea / Buck
Location: Connecticut

Post Fri. Nov. 08, 2013 9:05 am

Well said Mike.

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dave brode
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Posts: 478
Joined: Fri. Jan. 15, 2010 5:47 pm
Stoker Coal Boiler: Keystoker KAA-2
Hand Fed Coal Boiler: used to have a 5 section Red Square
Coal Size/Type: rice anthracite
Location: Frostburg, Maryland [western]

Post Tue. Nov. 19, 2013 9:50 pm

Joe,

Could you locate a normal DHW tank next to the boiler?

I have a normal 50 gallon elec beside my KAA2. A short "gravity" loop runs from the bottom of tank, through the boiler's coil, and back to the top of the tank. I switch the elec off when I have a fire in the boiler. I must note that I also have side-arm style water "pre-heaters" on the boiler piping that warms the well water prior to it entering the tank. I haven't tested to see how much heat they add to the 58* ish water from the well, but some for sure.

Sorry, pics aren't the greatest. Taken during boiler install. The first 3 pics show sloped 'gravity" piping.

Dave
Attachments
Oct09^06.JPG
Oct09^06.JPG
Oct09^06.JPG
Last edited by dave brode on Tue. Nov. 19, 2013 10:12 pm, edited 2 times in total.
I love my Kaa-2. It replaced a small 5 section Red Square, and Iron Fireman, burned bituminous for 20 yr.


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dave brode
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Posts: 478
Joined: Fri. Jan. 15, 2010 5:47 pm
Stoker Coal Boiler: Keystoker KAA-2
Hand Fed Coal Boiler: used to have a 5 section Red Square
Coal Size/Type: rice anthracite
Location: Frostburg, Maryland [western]

Post Tue. Nov. 19, 2013 10:00 pm

Pic showing the "side arm" style pre-heaters on boiler piping. Well water pics up heat from return then supply, then down to tank inlet. Other "in pipe" is for summer use, bypasses side-arms. The "side arms" are valved off, so water doesn't travel through them in summer.

note: side arm style heat exchangers are made by running 1.5" boiler piping through 2" [ground stops out of the tees]

note - there is one big difference between what's shown and how piping is run now. Supply water from side arms to DHW tank now does not run into normal top inlet of the tank. It now runs down and tees into the gravity loop at the bottom of tank. Water can enter both the bottom of the tank, AND the boiler's coil from said tee. This forces at least some of the supply water through the boiler's coil while water is being drawn. How much, I'm not sure, but it made a huge improvement. Hot water is pretty much endless now. Prior to the change, a 2nd consecutive shower was getting cool.

I can post pics of the change if you are interested.

Dave
Attachments
Oct09^12.JPG
Oct09^13.JPG
I love my Kaa-2. It replaced a small 5 section Red Square, and Iron Fireman, burned bituminous for 20 yr.

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Lightning
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Posts: 8304
Joined: Wed. Nov. 16, 2011 9:51 am
Hand Fed Coal Furnace: Overmodified/Bored out Clayton 1537
Coal Size/Type: Anthracite/Awesome Size
Location: Olean, NY

Post Tue. Nov. 19, 2013 10:25 pm

NJJoe wrote:Option 2. Use the boiler DHW coil and plumb the output to the input of a water heater. The coil could preheat the water entering the water heater and possibly lead to less water heater energy usage.
Expected DHW usage is for 2 people at the moment doing regular laundry loads, showers/baths, dishwashing and cleaning. Would like to build reserve capacity into this system for possibly more people.

Nothing is built, this is still in planning phase. Any opinions would be appreciated. Thanks...
Option 2 hands down.. Why fiddle with coal in the summer for two people? For a family of 6, yeah sure... Doesn't seem to me it would warrant the heating load for two people.. Do a good job prepping it in the spring and forget about it till fall.. Plumb in a bypass so cold water isn't going thru it. 8-)
titleist1 wrote: one reason I like the change of seasons because I get tired of doing the same chores. I get tired of cutting grass toward the end of summer while at the same time I look forward to starting up the coal stove, I get tired of raking leaves and am glad when they are all back in the woods, but look forward to moving the occasional snow we get, by the time spring rolls around I am ready to shut down the coal stove (blasphemy, I know) and not have to deal with loading it up and emptying the ash, but I look forward to cutting grass.

i said all that to justify my personal choice - option 2! :gee: (with the bypass you mentioned)
Amen Brother!! :D Save summer for summer stuff :lol:

NJJoe
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Posts: 259
Joined: Wed. Jun. 08, 2011 1:28 pm
Location: Southern NH

Post Wed. Nov. 20, 2013 10:23 am

dave brode wrote:I can post pics of the change if you are interested.
Yes please. Perhaps a before and after pic would help me to understand what you accomplished here and how it is supposed to work.

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dave brode
Member
Posts: 478
Joined: Fri. Jan. 15, 2010 5:47 pm
Stoker Coal Boiler: Keystoker KAA-2
Hand Fed Coal Boiler: used to have a 5 section Red Square
Coal Size/Type: rice anthracite
Location: Frostburg, Maryland [western]

Post Wed. Nov. 20, 2013 9:04 pm

NJJoe wrote:
dave brode wrote:I can post pics of the change if you are interested.
Yes please. Perhaps a before and after pic would help me to understand what you accomplished here and how it is supposed to work.
Joe,

Will do. send me a pm if I forget and don't post back by the weekend
I love my Kaa-2. It replaced a small 5 section Red Square, and Iron Fireman, burned bituminous for 20 yr.

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dave brode
Member
Posts: 478
Joined: Fri. Jan. 15, 2010 5:47 pm
Stoker Coal Boiler: Keystoker KAA-2
Hand Fed Coal Boiler: used to have a 5 section Red Square
Coal Size/Type: rice anthracite
Location: Frostburg, Maryland [western]

Post Sun. Nov. 24, 2013 3:43 pm

Joe,

I'll post pics. Realize that what I'm calling 'side-arm" style heat exchangers on my boiler mains are functioning as pre-heaters. They heat the water coming from the well. The syphon, or gravity loop connected to my boiler's coil is doing most of the work.

The water comes from the well, and goes through the sidearm on the boiler's return, then jumps over to the sidearm on the boiler's supply. The water from well then goes down to the tee at the bottom, of the tank. From there it goes into the bottom of the tank, AND through the coil, and back to inlet in the side of the tank. Prior to the change, the water from the well ran only into the normal top inlet of the elec tank, and the gravity loop heated the water parked in the tank. That piping routing is shown in the Nov 19th post. Prior to that change, when water was drawn, it went directly into the normal top inlet in the tank. Now, the water enters the tank through either [both side inlets on the tank. None enters the normal top inlet.

Dave
I love my Kaa-2. It replaced a small 5 section Red Square, and Iron Fireman, burned bituminous for 20 yr.

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dave brode
Member
Posts: 478
Joined: Fri. Jan. 15, 2010 5:47 pm
Stoker Coal Boiler: Keystoker KAA-2
Hand Fed Coal Boiler: used to have a 5 section Red Square
Coal Size/Type: rice anthracite
Location: Frostburg, Maryland [western]

Post Sun. Nov. 24, 2013 4:00 pm

I'll post some pics asap. I have a new computer, and a new camera. I'm having a helluva time with both
I love my Kaa-2. It replaced a small 5 section Red Square, and Iron Fireman, burned bituminous for 20 yr.

User avatar
dave brode
Member
Posts: 478
Joined: Fri. Jan. 15, 2010 5:47 pm
Stoker Coal Boiler: Keystoker KAA-2
Hand Fed Coal Boiler: used to have a 5 section Red Square
Coal Size/Type: rice anthracite
Location: Frostburg, Maryland [western]

Post Sun. Nov. 24, 2013 5:43 pm

1st pic shows the original route from side arms down to normal inlet in top of tank. the two valves on the piping above the tank allowed bringing water directly from well, or routing through side arms.

2nd pic shows original connection of bottom of gravity loop from bottom of tank through boiler's coil, and back into side inlet high in tank.

3rd shows gravity loop top connection to tank.

4TH is a not too good pic that barely shows the loop's connections at boiler's coil.

This is how I originally had it piped. The loop did keep parked water hot, but a 2nd shower, or a shower after a load of laundry was getting cold. Even so, I still switched elect tank off when there was a fire in the boiler. After the water in the tank cooled some, it would take a few hours for the gravity loop to bring it back up. Fwiw, I did have a small pump on the gravity loop for a while. it could be used to speed up the gravity loop, but for reasons that I will not go into right now, I scrapped that some time ago.
Attachments
sidearm to tank original.JPG
flue 5.JPG
gravity loop top.JPG
flue 1.JPG
I love my Kaa-2. It replaced a small 5 section Red Square, and Iron Fireman, burned bituminous for 20 yr.


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