Harman SF-250 owners...

2 questions:

How much are they getting for those, & what kind of hot water temps are you getting with the optional coil (if anyone is using it)?

I was thinking if the coil gets the water temp high enough, I could plumb it in to the oil furnace & keep that expensive pile from running.

I'm sick of burning $3.20/gallon oil -- I think it's time for an upgrade! Just filled oil tank -- $650 with 30 gallons still in it!

Getting that massive piece of steel into my basement looks like it may be loads of fun...

Hey Smitty,

I can't talk about the SF-250, since I have the same stove as you have, but based on what you have posted in the past it would help out your heating situation, if I remember correctly, the Mark I doesn't produce enough heat for your place. Maybe you could keep the Mark I connected to the flue, you could run both when it's really cold.
I do know that you need to have a storage tank to use the stove to heat domestic hot water. If you oil burner has a coil type water heater the results probably won't be good. You could get a used 40 gal. water heater in decent shape to use as a holding tank.
I'm in the process of installing a stoker with a hot water loop in it that I will plumb into my 30 gal. Aero Loboy hot water tank (oil fired) to heat domestic hot water. When I'm done the oil burner will still be able to fire under high demand, I'm hoping most of the hot water needed will be supplied by the coal burner.

http://cgi.ebay.com/Harman-SF-250-Coal- ... dZViewItem

Here's one on ebay for $450.00, just listed today in PA.

Wood'nCoal wrote:Hey Smitty,

I'm in the process of installing a stoker with a hot water loop in it that I will plumb into my 30 gal. Aero Loboy hot water tank (oil fired) to heat domestic hot water. When I'm done the oil burner will still be able to fire under high demand, I'm hoping most of the hot water needed will be supplied by the coal burner.

That's exactly what I need to do.

I have been tossing around a few ideas on how to use the coil.

One was to circulate the water thru the coil in the stove, then into the oil furnace. I have a 41 gallon indirect-fired boiler hooked up to the oil furnace as a 4th heating zone with it's own circulator (absolutely CANNOT run that thing out of hot water! Works great!!). The little computer on the boiler sends a signal to the oil furnace when it needs heat & it kicks on the circulator & the oil burner, if needed. If I could get the water in the oil furnace hot enough, the burner would never kick on to heat the hot water in the indirect tank.

The furnace also has a tankless coil that we used to use for hot water (sucks). It's not connected to anything now. Was thinking I could circulate the stove coil water thru that to heat the furnace, but judging from the sucky hot water we used to get out of it, the heat transfer will be useless.

The other idea I got from Greg -- run the icy cold water from the well, thru the water coil in stove, then into the indirect tank so the water is only being heated a few degrees versus 80*. But I would have to get another tank (i'm running out of space here!) to circulate the water when we're not using the domestic hot water to prevent a

Another idea I had was to get an 80 gallon tank connected to the stove & hook everything in parallel to it from the oil furnace. That way i could use the hydronic heat too. I'd probably have to slow the circulating water waaay down to get any kind of heat out of it, though.

I'll figure something out eventually .........I figure this is easier than insulating the house!

coalkirk wrote:http://cgi.ebay.com/Harman-SF-250-Coal-Wood-Stove-furnace_W0QQitemZ190192661772QQihZ009QQcategoryZ41987QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

Here's one on ebay for $450.00, just listed today in PA.

That figures! I've been looking for one on there for a while -- was going to buy one but never saw one for sale, so I figured I'd buy a new one next year. So I went ahead & bought my wife a newer RUST-FREE truck from down south. After shipping, ALL MY $$$ IS GONE!

My luck never fails...

Hi Smitty, your ideas are great, but the big [or little] problem is the area of the hot water coil in the stove.. Take a look at the heated surface in a coal boiler, lots and lots of square feet.. the surface area of the hot water coil is less than one square foot.. So you aren't going to get enough heat out of the small loop to heat the water in the boiler.. Take a look at this thread: custom water coil setup for Channing III
You can see what was needed to get a significant amount of heat out of a coil.

So you can get heat from the coil, but not loads of heat every hour.. the coil is meant to slowly heat a hot water tank and give you overnight or through the day a tankfull of hot water. A much bigger coil is needed to heat the amount of water you need. It can be done, but will need some creativity.

Hope this helps.. Greg L

Below is the interior of an EFM 520's firebox and heat exchanger, look at all the surface area!!


.

Thanks for the help Greg!

Now, what would happen if I slowed down the circulating water with a manual valve? Would it just turn the water to steam & cause a problem?

SMITTY wrote:Thanks for the help Greg!

Now, what would happen if I slowed down the circulating water with a manual valve? Would it just turn the water to steam & cause a problem?

That's what I plan to do, with thermometers on the inlet and outlet lines to the loop in the stove, I can adjust the ball valve to get the flow set to get the most heat.

Hi Smitty
I just got done posting a post in (introduce Yourself) tellin my storey. check it out and maybe it will help you. if you have any question about it i can try and answer them.

Wood'nCoal wrote:That's what I plan to do, with thermometers on the inlet and outlet lines to the loop in the stove, I can adjust the ball valve to get the flow set to get the most heat.

That's a great idea!

I was just looking at a setup like that in the link that Greg posted above. The previous owner of my house installed a couple of those thermometers in the return lines of 2 of the heating zones. I broke one of them last year while fixing a leaky valve, but before I did I got to watch the temp difference that showed how overloaded one zone was compared to the other.

I just had another idea......If I hooked the coil from the stove into the tankless coil in the furnace & circulated the water thru that, and then teed into that line to supply water to the indirect boiler. That way, when the domestic hot water is not used, the water will continually circulate & dump the excess heat into the furnace. Although, I think the oil furnace would be doing the heating instead of the coal, due to the small surface area.

Time for bed -- I'm not used to mental labor, just physical labor!

Thanks for the ideas guys! Keep 'em comin'

Hi razzler, could you go to your post in the 'introduce your self' thread, cut and paste your coil information and post it here on this thread.. this would help those following this thread's ideas.

thanks. Greg

hey Smitty
I have a mkI in the basement of my old house it keeps my floors warm and that was about it so I installed a hilkoil 16T and ran it in parallel with my gas boiler and it helps a lot my gas bill for dec. was $60 and $30 of that runs the hot water tank and I keep my 1700 sq ft house built in 1879 at a toasty 74* I circulate the water through my boiler and base board heat constantly and I can adjust the water temps from 90* t0 160* I have remodeled and insulated outside walls but no insulation in the attic and a drafty stone fondation I think this could take the curse off that oil bill for little money here is the link for hilkoil http://hilkoil.com/
Dan

Hope this helps
I put a hilkoil in and hooked it in to my EFM boiler but couldn't keep the water temp up much past 140* for a domestic hot water tank that would be fine, but not if you want to try to heat the house. So i designed my owne ciol, the hiokoil was 57" long and the one i made was 120" and it still wasn't anuff. I could get the water to 170* but couldn't maintain it to long. Now i install the 57" ciol in as well it was a tite fit but i got it in there and hooked it in sequel for total of 15ft. Now i can heat the hole house and the domestic hot water as well i can maintain between 160* and 180* the only time the oil burner will kickin if there are back to back showers (with three women in the house )that uses alot of hot water and then it will only run for 3 minutes or so. Harman makes a great stove the SF250 can make alot of heat.

SMITTY wrote:2 questions:

How much are they getting for those, & what kind of hot water temps are you getting with the optional coil (if anyone is using it)?

I was thinking if the coil gets the water temp high enough, I could plumb it in to the oil furnace & keep that expensive pile from running.

I'm sick of burning $3.20/gallon oil -- I think it's time for an upgrade! Just filled oil tank -- $650 with 30 gallons still in it!

Getting that massive piece of steel into my basement looks like it may be loads of fun...

i was looking at new ones last week. they were anywhere from $2k- 2200

i thought i found a used one, turns out it's a 150.

i just finished getting it hooked up in place of my hearthstone mainsfield.

the jury is still out, i really like the bigger firebox on the 250.

worse case i'll go get a new 250 or a sf-2500 and sell the 150

Thanks everyone for all the input.

I may buy that unit sometime before next season. In order to get that beast into the basement, I'll have to remove a door & frame, plus disassemble part of the wall in order to make the tight turn down the stairs. Now....... once I make that turn, well, that's where the fun starts!!

I'll have the motley crew here to help me -- I just hope the stairs hold up!! There will be a LOT of drinking after that project is done!

It needs to go down here: