Harman Mark II

Harman Mark II

PostBy: jrplumber87 On: Fri Aug 09, 2013 6:57 pm

Hello all! Awhile back I posted a question about the Reading Swatara. I never received a response and long story short I never bought the stove. However, after last winter (cold here in NY) I need to get off my butt and settle on a stove. I have one question about the Harman Mark II. If anyone out there has one, what is the average unattended burn time you are getting out of it. By unattended I mean no shaking, filling, or poking. They advertise 24 hour unattended burn but the real world is different. This stove would be the perfect size for my 1300sq ft house. The only reason I ask this is I am a heating technician and sometimes I get home a few hours late in the winter and I don't want to come home to a cold stove and the sound of my propane furnace running if I can help it. Thanks for your time! I would appreciate any insight anyone has.
jrplumber87
 
Stove/Furnace Make: alaska
Stove/Furnace Model: channing 2

Re: Harman Mark II

PostBy: Anthracite Ed On: Fri Aug 09, 2013 7:09 pm

Greetings , I have been burning a mark II for about 12 years in central penna, in the dead of winter I get about 8-10 hours unattended,
Anthracite Ed
 
Hot Air Coal Stoker Stove: Alaska Channing III
Hand Fed Coal Stove: Harman Mark II
Coal Size/Type: UAE Classic Deep Mined
Other Heating: Electric Heat Pump
Stove/Furnace Make: Harman
Stove/Furnace Model: Mark II

Re: Harman Mark II

PostBy: jrplumber87 On: Fri Aug 09, 2013 8:18 pm

Thank you! Not as long as I expected for burn time but your info is valuable! Thank you for your time. I'm sure experimenting with pea and nut mix and adjusting air intake could extend these burn times. If anyone has more input please chime in. Thanks!
jrplumber87
 
Stove/Furnace Make: alaska
Stove/Furnace Model: channing 2

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Re: Harman Mark II

PostBy: jpete On: Fri Aug 09, 2013 8:24 pm

I had a Mk I and now have a Mk II.

I typically tend mine twice a day. If I'm running it hard, maybe 3.

Normal routine is tend it in the morning before work. ~6:30am

Hit it again anytime after work between 4pm and 7pm.

Then maybe a quick shake and top off the fire box before bed at ~11pm.

That's not to say the stove "needed" to be tended. Those are just easy times for me. I went 22hrs on my Mk I once but I don't think I'd try that every day.

And for the record, I normally burn nut in the early and late seasons and stove in the dead of winter.
jpete
 
Hand Fed Coal Stove: Harman Mk II
Coal Size/Type: Stove, Nut, Pea
Other Heating: Dino juice

Re: Harman Mark II

PostBy: Chuck_Steak On: Sat Aug 10, 2013 10:27 am

As a heating tech, you know it is strictly a math proposition..
24 hour burn does work.
If it's cool outside, and you need to take the chill off.
If it's zero outside and windy, you may only get 8-10.
All depends on temp differential, and how warm you want to be..

Dan
Chuck_Steak
 
Coal Size/Type: mostly nut, sometimes stove, Santa brand
Stove/Furnace Make: Harman
Stove/Furnace Model: Mark III

Re: Harman Mark II

PostBy: JohnB On: Sat Aug 10, 2013 6:49 pm

You might want to also consider the Hitzer 30-93. The 30lb gravity feed hopper would give you longer burn times.
JohnB
 
Hand Fed Coal Boiler: Hitzer 50-93

Re: Harman Mark II

PostBy: SMITTY On: Sun Aug 11, 2013 12:50 am

I used to get 10 -15 hour burn times until I switched brands of coal. Kimmels to Blaschak.

My Mark III will easily go over 24 hours during the not-so-cold part of the fall. During a sub-zero January night, that gets knocked back to about 18 or so.

Sure, I could refresh it every 12 .. but why? It's enough work as it is. Besides, if it's still burning hot, refreshing is a waste, IMO.
SMITTY
 
Stoker Coal Boiler: Patriot Coal - custom built by Jim Dorsey
Hand Fed Coal Stove: Harman Mark III (not currently in use)
Coal Size/Type: Rice / Blaschak anthracite
Other Heating: Oil fired Burnham boiler

Re: Harman Mark II

PostBy: Lightning On: Sun Aug 11, 2013 3:56 am

jrplumber87 wrote:The only reason I ask this is I am a heating technician and sometimes I get home a few hours late in the winter and I don't want to come home to a cold stove and the sound of my propane furnace running if I can help it. Thanks for your time! I would appreciate any insight anyone has.

I don't have a mark II or a "stove" for that matter but hopefully this may help. I have a hand fed furnace much tended to the same way as a stove would be. My opinion is that an appliance properly sized for the space should get 12 hour tending times minimum thru a majority of the winter. Occasionally when its below normal cold, tending 3 times a day may be required to maintain a steady high heat output. That's why we love coal right? To get burn times that don't make us a slave to the heat 8-) SO, it would be wise to figure out how many BTUs you average use thru an average winter day and take it from there. It may take some math work to figure out your btu needs based on propane usage. Since yer a heating technician the following should be right up your ally :) I had a 100,000 BTU propane furnace (which nets 80,000) so I decided to go after an appliance that could max 120,000 btu (which would net 100,000 btu) so I would have the extra umph to get thru the abnormal lows without more than 2 tendings per day. On the coldest days I burn 75-80 pounds which is roughly 42,000 btus per hour to maintain 75 degrees in the house. Keep in mind that maximun rated btu output from the manufacturer isn't realistic. I would never want to push my furnace to produce 100,000 btus per hour. It probably wouldn't be safe and definitely wouldn't be efficient. My opinion would be to get a stove that is rated double what you need, so you don't have to crank the hell out of it and you could maintain the steady heat output required to get 12 hour burn times. Once you learn the burn, you'll see that even an oversized appliance can be cut back to throw low heat on warmer days. Those days you could get a 18-24 hour burn and not heat yourself out of the house. Better oversized than undersized. :D
Lightning
 
Hand Fed Coal Furnace: Clayton 1537G
Coal Size/Type: Nut Size / White Ash

Re: Harman Mark II

PostBy: lowfog01 On: Sun Aug 11, 2013 6:58 am

The Mark II is a heat monster that you should be able to get a 20 hour burn out of with no effort. I've burned one for 7 or 8 years and get 12 - 14 hour burns routinely because that's what convenient for my schedule, I get up in the morning I tend the stove, I go to bed I tend the stove. The one issue I know you will have with the Mark II is the small ashpan. That will fill up fast - get two if at all possible so you can switch them out quickly. The Harman is a very easy stove to use and as I've said is a heat monster. Good luck, Lisa
lowfog01
 
Hand Fed Coal Stove: Mark II & Mark I

Re: Harman Mark II

PostBy: wilder11354 On: Sun Aug 11, 2013 8:07 am

not a Mk2 user, but i live a few miles down the road from you. 12 hour burn times should be no problem, except on extremely cold/windy days. i burn a SF260 boiler, go 12 hours between tendings. Extreme cold days i try to get home mid day to top off with a little bit more coal, to ensure it will keep up the burn, and not get to low a fire and have a long recovery time after tending. But it will burn for 12 hours on the extrememly cold days, just takes longer to restoke the bed of coals.(recovery time).
wilder11354
 
Hand Fed Coal Boiler: Harman SF260
Coal Size/Type: nut or pea, anthracite
Other Heating: crown oil boiler, backup.if needed

Re: Harman Mark II

PostBy: michaelanthony On: Sun Aug 11, 2013 8:12 am

...like jpete say's, it's about what works for you and your schedule. If I didn't have to get up and out for work I could squeeze 16 -20 hrs. of moderate heat, but I want HEAT and more than moderate so my stove works on my schedule not the other way around!
michaelanthony
 
Hand Fed Coal Stove: Vigilant 2310, gold marc box, vogelzang pot belly coat rack
Coal Size/Type: Pea, and a little nut
Other Heating: Very cold FHA oil furnace

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