How many tons to purchase for season?

I am new to burning coal. I have purchased a new hand fired firechief 700 furnace (150K). The furnace has a forced draft blower and a rotary grate. Furnace will burn coal or wood it has a long skinny fire box. I have not burnt any wood for 10 years or so used to heat with wood only then went to fuel oil. Oil has gotten to expensive so I am going give coal a try.The house is 1800 sf well insulated located in upstate NY. I have thought about getting 1 ton of pea coal for fall and spring and 2 tons of nut coal for the cold months.
I use approx 3 tanks of oil per season which comes out to 750 gallons. I have searched and found site that says I would need 2.6 tons based on 750 gallons of oil. Does this seem right ? I would like to know how much other people are using for a season.

Please post a photo of your firebox with dimensions.. that description makes me concerned about it's ability to burn coal well... I'd use nut coal.. Pea is probably too small for the unit...

I'd recommend buying some bagged coal first and finding out if your furnace will burn coal well enough to make buying several tons worthwhile..

Roughly put, 180 gallons of oil is equal to 1 ton of coal.. if burnt and distributed to the house with the same efficiency.

Greg L

Thanks for the reply my firebox dim. are 28 inces deep x 18 wide at top of fire brick and tapers down to 8 inches over the rotary grates. Do you see a problem with burning coal in this stove?
I will try to figure out how to post a few pics of fire box.

Directions here for posting images: post photo

As I suggested in the other thread I'd get 4 or 5 tons. Be sure to test it first before committing to large purchase.

Here are afew pics of furnace with fire box.
Thanks for the help that you have given thus far.

Nice looking furnace jimbo. Good luck with it!

Well, a lot of times the 'V' shaped firebox causes problems,, A well designed firebox for burning coal has vertical sides or nearly vertical sides.. The problem is that coal has at least 10% ash,, and as the coal burns,, the coal bed settles down with a tapered 'V' firebox, the coal and ash get compressed together as it settles,, this causes clinkers. and the concentrated ash on the grate can cause airflow problems..

I built my own boiler using the 'V' shape,, and regretted it.. If I were to build another hand fired stove or boiler the sides would be vertical, and the firebox very deep, so I could easily have a coal bed that is at least 10" deep.. this is what anthracite likes.. a deep fire with vertical sides..

Do a search on the forum for US stove, and wood coal combination. You will find several threads about the frustration some members have had burning in these type of stoves..

Your particular brand, I don't think has been mentioned on the forum before,, maybe the smaller firebox will work for you.

Greg L..

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The grates appear to be too big for pea and it would fall through***, it's roughly the size of quarter if not smaller. Your best bet as suggested would be to get 4 or 5 bags of nut and try it out. If it works as i suggested I'd get 4 to 5 tons. Not sure where you came up with the the 2.5 tons but 1 ton of coal is about 180 gallons of fuel oil. Going by that you're over the 4 ton mark.

***What you can do is if you find it burning a lot an you can't control it is use the pea over the top of the nut or mix it with the nut.

That looks just like my Steel King, the firebox will work fine with good coal. If you have poor quality coal and/or overfire it, it may become cranky (clinkers). Examine the combustion blowers duct and be sure there is no overfire air allowed. Some of these combo wood/coal units have overfire air ports in them and it won't help your learning curve with coal. Mine had two quarter size holes at the top of the airbox, plugging them really made life a lot easier.

Jimbo, nice pictures. There are may on here that can help you more regarding pea vs nut though heres my enjuneer data put. My Mark II has a .9 cu ft coal volume and expect around 2-2.5 tons based on what I've read here. Based on the pictures and assuming a ~20" firebox length you have something like 1- 1.3 cu ft of coal up to the brick top (I could be wrong here..it's a V shape..I did a rough box and divided by 2 because of the V ) . At every recharge you always should have some burning coal remaining so lets say every recharge takes 1 cu ft of coal..that is ~50 # coal....maybe 2X per day for 80-100 lbs per day. You can go from there. Be interesting to see your cu foot capacity assessment up to the tops of the bricks plus some banking. Also, consider that each lb of coal has around 13.2 K btus so with something like a 65-75 % efficiency, your heat out put is ~9K btu's per lb. Your home sounds pretty energy efficient, so you may find to some degree that you can idle this baby pretty low, which may be good to avoid the clinker issues discussed prior cause by overfiring with a V. I'm pretty much a newbie here on the forum, like to do calculations stuff, see ya.

Thanks for all the tips and info. I checked my draft blower duct and it does have over fire holes I am going to get them plugged off before I fire it. I went and bought 1 bag of nut coal today and am going to try to burn it at the first chance I get. I asked about price and was told it is at $269 a ton now and is going to jump to $289 July 1st. I am not going to be able to fire furnace before july 1st so I guess I will be paying $289 for coal.

You will need at least six inches of coal in your firebox for it to burn properly, might want to get a few more bags.

Jimbo, one of the keys to good coal fire is you have a lot of it, you need a deep bed. Control it through the amount of air.

jimbo wrote:Thanks for all the tips and info. I checked my draft blower duct and it does have over fire holes I am going to get them plugged off before I fire it.

I am not going to be able to fire furnace before july 1st so I guess I will be paying $289 for coal.

I just tapped the holes and put bolts in them. Make sure any vents in the door are closed off too.

Save yourself some money and buy the coal now. It can sit a few centuries without going bad, not so with money (which you will have more of now ).

That firebox will require a very deep bed to stay out of trouble. If the water jacket runs down to the firebrick you can fill it deeper than the top of the firebrick. When it is real cold, I'll fill mine right to the bottom of the door.

Guys
Thanks for info I will go today and buy a few more bags to try and make sure I get a good bed of coal at least 6 inches deep.
How long should that burn with it throttled down?