2 zones off a keystoker boiler

I have my boiler set up with 2 zones, one for the house the other heats the barn. What I'm wondering is too much for the boiler? Are you supposed to have just one zone. I seem to burn more coal, then when I was just heating the house, which is understandable. But it always seems to in the demand mode. Is there a protocol for a 2 zone system? The instructions of course only show one thermostat. Anyone have suggestions or knowledge that would help me?

You can have as many zones as you want. When you get multiple zones (especially if one or more are small) the control strategy changes a little, but it isn't a big deal.

How is the extra zone wired and piped?

ranger13148 wrote:I have my boiler set up with 2 zones, one for the house the other heats the barn. What I'm wondering is too much for the boiler?

First

do a heat loss calculation on your load so you know what to look for - size is everything

http://www.pvsullivan.com/Downloads.html

Download this heat loss calculator if you want to do the best job for your self - It will conclude exactly how big of a heating appliance you really need. Too big a boiler is a fuel hog -- too small -- well your cold This will even tell you - if you listen = how to size your zones distribution to the zones and the pumps.

or

Here’s an example of a no brainer version:

http://www.builditsolar.com/References/ ... atLoss.htm

I have my boiler set up with 2 zones, one for the house the other heats the barn.

What square footage are you heating with the 2 zones?

I spoke with someone at Key stoker, he got me a bit more settled down on coal burn. I was running from very high, over 200 to a low of about 140. Now my temps aren't fluctuating as much. I'm going from 180 to 160 now. I'm heating about 2200 square feet between the house and my barn. The barn is much better insulated than the house is and I don't keep that as warm as I do the house. My main concern was efficiency. The ash bucket has very little unburnt coal, but what comes off the grate seems to clump together, sometimes causing the bucket to overflow, even tho the bucket isn't really full. This is only the 2nd year I've been heating both buildings off the same unit. I used to bucket coal over to the barn and used an Alaskan stove over there. Now I've eliminated that chore at least. I thank you all for your answers and suggestions, and would still be willing to hear any other ideas you may have to better run my system.

Rob R. wrote:You can have as many zones as you want. When you get multiple zones (especially if one or more are small) the control strategy changes a little, but it isn't a big deal.

How is the extra zone wired and piped?

I have a Modine unit heater hanging from the ceiling in the barn, which has a blower motor behind it, kinda like a radiator in a car. This zone is about 80 feet total in supply and return lines. The lines run 4' underground in an insulated pipe, same as they have for and outside wood boiler. The house lines are much more than that maybe 150' with a supply side and a return side. The coal boiler circulates through the oil boiler, which is for back up and heating domestic water during the warmer months. There is a switching relay for the thermostats which tells which circulator pump to turn on, or both if needed. If the boiler gets to hot it will pump the extra heat to the barn. I suppose that's about as best as I can describe what I have and what I'm doing with it.

Your system sounds like it needs to have some time to teach you about adjusting it. Long runs for the house, however the loss should not be an issue, and an active dump zone....all good logic and piping.
Understand that your coal usage is still less than half of what oil or gas would cost- wise; so don't think a bag a day will satisfy a heat loss of 80K.....plus hot water production.
Without a heat loss, you are flying by the seat of your pants, and that may well be fine, so relax, and learn as you burn. History for next season is what you are recording right now.

I suggest you keep a log of daily usage as best you can, and/or install a run-time meter on the stoker motor.
If you are using 100 lbs a day that produced 100 times 13,000 btu's per pound/24hrs or 55,000 btu's per hour. 55K/13000=4.25 lbs/hr.
Oil would require the same btu, but run time would not be at 55k/hr so now you have 1,300,000 btu requirement and 134,000 production per hour of boiler run time...or about 10 hrs a day of run time.

Ten hours through a 1.00 gph nozzle or 10 gallon times $3.50+/- or $35.00 a day with oil. 100 lbs of coal at $7.00 a bag...or $14 a day for coal.
Simple numbers, rounded off, but coal is producing more radiant heat off the boiler, thus surrounding areas get 'conditioned' as a benefit.


Comfort level: PRICELESS!

I don't believe I'm using 100 lbs of coal. I'd say I'm more like 40-50 lbs. I'm not sure what a 5gal bucket of coal weighs. I'm estimating, I'm using 2 5gal pails a day to heat both areas. I suppose I can weigh a bucket and find out for sure. I only dump one pail of ashes per day, and that pail is not full to the top, but close. What I have seems to work well as both areas are comfortable, I'm trying to be as efficient as possible is all.

ranger13148 wrote:I don't believe I'm using 100 lbs of coal. I'd say I'm more like 40-50 lbs. I'm not sure what a 5gal bucket of coal weighs. I'm estimating, I'm using 2 5gal pails a day to heat both areas. I suppose I can weigh a bucket and find out for sure. I only dump one pail of ashes per day, and that pail is not full to the top, but close. What I have seems to work well as both areas are comfortable, I'm trying to be as efficient as possible is all.

Figure about 38 to 42 lbs. per 5 gallon pail, depending upon the coal, and upon how full the pails are. Call it 40 lbs. per pail.

It's pea coal, and I'd say they are usually about 3/4s the way full.

ranger13148 wrote:It's pea coal, and I'd say they are usually about 3/4s the way full.

Then you are currently burning about 60 lbs. per day. I'd say that is quite good.

ranger13148 wrote:It's pea coal, and I'd say they are usually about 3/4s the way full.

Will a Keystoker boiler reliably feed and burn pea?

lsayre wrote:

ranger13148 wrote:It's pea coal, and I'd say they are usually about 3/4s the way full.

Will a Keystoker boiler reliably feed and burn pea?

Not unless the pea is undersized...in which case it would really be buck.

2200 sq. ft with underground piping and domestic hot water is a sizeable load for a KAA-2 boiler. Don't be surprised if it runs 12-15 hours per day in cold weather...maybe more - and as long as it meets your needs, that is fine.

Free advice - if your boiler is being pushed to max capacity in cold weather, I'd plan on giving it a brush down sometime in January.

I did post pea, I'm sorry I meant rice.

Just checking to see who was awake and who was a zombie......good trick!