Need Help Deciding Which Keystoker Coal Boiler To Buy

Need Help Deciding Which Keystoker Coal Boiler To Buy

PostBy: coollx On: Tue Jul 08, 2008 1:03 pm

I'm new to this forum and am seriously considering the purchase of a Keystoker coal boiler to serve as an add on and primary heat source to my present oil fired boiler.

I need help deciding whether to purchase a KAA-2 or a KA-6 Keystoker.

Here's some background on my oil boiler and oil usage.

- 1900 SF ranch house on main floor...basement unheated except if using my workshop
which has a separate zone tied into my current boiler
- Also have a stand alone oil fired hot water heater for all domestic HW
- I use about 1100 gals of fuel oil a year
- current oil boiler has a hot water rating of 142,600 btuh and 950 SF
- The burner capacity is 1.5 GPH which has been significantly downsized now using a .85
nozzle

The dealer I'm talking with initially said the KAA-2 model would be fine based on the houses' SF but later said based on the amount of oil I'm using the KA-6 may be a better choice. I'm guessing the stand alone hot water heater uses 50-75 gals of the total oil consumed.

I don't want to buy a unit too large or too small. Plus theres a $1000 difference in price between a KAA-2 and a KA-6 which would buy alot of coal.

I'm hoping some of the experienced people on this board can give me some input and recommendations on which unit to go with and why.

Thanks

Dom
coollx
 

Re: Need Help Deciding Which Keystoker Coal Boiler To Buy

PostBy: Blackdiamonddoug On: Tue Jul 08, 2008 1:27 pm

axemax 130 with a dhw coil would take care of heat and domestic hot water.
BDD
Blackdiamonddoug
 
Stove/Furnace Make: axemen 260 rebuilt by Matt
Stove/Furnace Model: stoker AA 260

Re: Need Help Deciding Which Keystoker Coal Boiler To Buy

PostBy: Yanche On: Tue Jul 08, 2008 1:43 pm

Buy the smaller unit. Plumb your existing oil and new coal boilers with a primary secondary loop. Most of the time your coal boiler will provide all the needed heat. Any boiler will run most efficiently at or near rated capacity. On the coldest but rare days when the coal alone can't produce enough heat the oil boiler will provide the additional needed heat. Save the cost of the larger boiler and put it into the piping/control system.
Yanche
 
Stoker Coal Boiler: Alternate Heating Systems S-130
Coal Size/Type: Anthracite Pea

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Re: Need Help Deciding Which Keystoker Coal Boiler To Buy

PostBy: Complete Heat On: Tue Jul 08, 2008 8:47 pm

I would go with the KA-6. I base my decision on hopper capacity. The KA-2 is going to require more tending to than a KA-6 (100 lb hopper vs. 275 lb hopper). 2000 sq. ft is going to take a bag a day (every other day loading on a KA-2). The KA-6 will go almost a week.

Mike
Complete Heat
 
Stove/Furnace Make: Axeman-Anderson
Stove/Furnace Model: AA-130/FHA

Re: Need Help Deciding Which Keystoker Coal Boiler To Buy

PostBy: efo141 On: Tue Jul 08, 2008 9:35 pm

Does Keystoker make an extended hopper for the kaa2? How long can you go before you have to pull the ash pan?
efo141
 
Stove/Furnace Make: New Yorker/Keystoker
Stove/Furnace Model: WC90-----/Kaa-2

Re: Need Help Deciding Which Keystoker Coal Boiler To Buy

PostBy: Complete Heat On: Tue Jul 08, 2008 11:30 pm

They do, but the ash pan is the limiting device then.

Mike
Complete Heat
 
Stove/Furnace Make: Axeman-Anderson
Stove/Furnace Model: AA-130/FHA

Re: Need Help Deciding Which Keystoker Coal Boiler To Buy

PostBy: coollx On: Mon Jul 14, 2008 5:00 pm

The theory mentioned by Yanche that most boilers run most efficiently at or near rated capacity makes sense. I guess I'd rather have a properly sized boiler than one that has a larger hopper for convenience but is too big. For me, adding a bag of coal every other day is not a big deal since I'm home every day anyways. I'm most concerned at this point about choosing the right size boiler based on my heating requirements.

Any other thoughts or comments would be appreciated.

Thanks

Dom
coollx
 

Re: Need Help Deciding Which Keystoker Coal Boiler To Buy

PostBy: vtec350 On: Mon Jul 14, 2008 5:47 pm

One thing to consider too is future additions, finished basements, garage heat, radiant floor heating. I could get by with the KAA-2 but chose the KA-6, I don't want to have to replace the boiler down the road if I decided to do any of the above. Also, besides the smaller hopper, the KAA-2 has a smaller blower motor.

Dave
vtec350
 
Stove/Furnace Make: Keystoker
Stove/Furnace Model: KA-6

Re: Need Help Deciding Which Keystoker Coal Boiler To Buy

PostBy: coalboy On: Mon Jul 14, 2008 6:23 pm

A buddy of mine heats his 900sf two story [ small house ] with K-2. he has two complaints. The hopper size,ash pan size. Must tend every day. You don't say how big your family is. Will the K-2 supply enough DHW. I have a 1500sf Two story.My dealers recommendation was the KA-6. From the other posts i have read. the advise was, size your new coal boiler BTU output. To what you currently have.
coalboy
 
Stove/Furnace Make: AxemanAnderson
Stove/Furnace Model: 1949 AA130

Re: Need Help Deciding Which Keystoker Coal Boiler To Buy

PostBy: Sting On: Mon Jul 14, 2008 6:44 pm

discount the advice to install based on whats there

who knows if that is correct

do your own heat loss calculation

this will help


http://www.slantfin.com/heat-loss-software.html
This link is broken, either the page no longer exists or there is some other issue like a typo.
Sting
 
Other Heating: BurnHAM=NG-gas

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