Should I get Rice or Buckwheat?

Upcoming will be the first year of real dollar saving use of my new Keystoker Kaa2.I have come to believe that it can take either size coal [rice/buck].Soon I will go and get the coal for the fall,which is coming fast.What has been anyone's experience with buckwheat in the Kaa2? I see Harmony has it for $145.Superior has it for $160. They are both good pricing and actually even-stephen for me since Harmony is a bit more of a drive and $15.doesn't get much fuel anymore. So,what should I be getting when I head North to collect it? Thanks Mike

Hi Mike. I don't have the answer to your question but from my experience, buck would be preferable if the kaa2 can handle it. It has less fines and consequently less dust. Good luck with your new baby.

Terry

I have the Kaa-2 and have burned both rice and buck (and mixed):

I think the unit is optimally designed to burn rice. However, sometimes the clinker/ash mass can get pretty big as it gets pushed off the burner and drops with a thud. Sometimes the rice backs up behind it and can dribble over the sides, unburned. My house is in Central NY, 2700sqft, DWH, family of 7. Yes, the Kaa-2 is undersized. Admittedly, but I had size constraints. Anyway, when it is really cold (0F), it needs to run almost flat out. That's when the over-flow/back up/spillage is a problem.

My dealer told me to try buck. Buck, he said, would be fine and work well but that it would be harder on the stoker. Both statements are true: buck burns fine, it doesn't roll over the sides as much, and the clinkers drop off way better. You will hear the stoker "groan and grind" more with the buck. In my experience, it also burned hotter. So, when super cold and the unit is struggling to keep up, buck seems to give it a little extra "boost" to keep the house warm (and avoid the dreaded oil boiler from kicking in."

Don't take this to be an endorsement of buck over rice. Like I said, I think rice is optimal. Rice seems to burn more completely, i.e. "all the way through." Digging through the buck ash, I'm sure that more incompletely burned coal is making it through the stoker and dumping. The Kaa-2 stoker grate is fairly short; even an inch or two would have made a big difference. Also, as mentioned, buck can give you a "boost." I think the bigger pieces allow air to squeeze through much easier, essentially fanning the coals. The fire is hotter, the flames are higher, and the boost works. But stack temperatures were the highest I had seen as well. So, hotter yes, warmer house yes, more un-captured heat going up the chimney yes. Clearly, I'm up against the limitations of heat transfer given the surface area of the combustion chamber.

1/4 to 1/2 buck in the mix seemed to be the best compromise, but only when I needed to push the little boiler. Otherwise rice.

Thank all of you for the reply.Kenbod ,I was hoping for a response just like yours.There is not much better than first hand knowledge.This house is very close in size to yours, so heat load would be roughly similar but we seldom get near that zero degree temperature you mentioned.I did realize that I was getting close to the wire in the boiler output sizing but it is my belief that the boiler should work rather than lay around,run on timer, and wait for a call for heat. I don't want excess standby loss. What I want to avoid is a two ton pile of mis-calculation.I very much like the 25% buck mix concept and I think that could be easily accomplished by loading the trailer with a ton or so of rice and then filling my 5 gallon buckets in the back of the pickup with buck. I do not like to see cold weather come but by the same token,I am getting anxious to shuffle coal and watch the antics of Mr.Keystoker. Mike

If you check around, you may find a dealer who sells the rice-buck mixed already. I don't know if many dealers do his, but there is at least one here that premixes it due to the demand locally. I'm not sure what the percentages are but it seems to be mixed fairly well. Good luck.

Jeff

Mike,

I purchased 6 tons for last winter and burned about 5.5 between mid October and mid April. In CNY, coal costs about $230/t delivered. Even at that, I think it idled too much in October (but I was excited to get it going) and I shut it down when it happened in April. This year, I think I'll target Nov-Mar (1 month less) and burn more oil. When burning coal, I try to factor in my work/effort as well as the costs of coal and oil.

By the way, even in CNY and even with DHW for a family of 7, we burned less than 50 gallons of oil all winter. That little Kaa-2 was a mighty mite. Sometimes I regret not buying the K-6. But practically speaking, the Kaa-2 was able to take on the vast majority of the load. When below zero, I just could not get the living room above 62F some mornings, but that was the only problem area.

I bought a tekmar 256 outdoor reset boiler control and it, too, was an impressive gizmo. Definitely worthwhile. No doubt.

Ken

Ken, it is my way of thinking that if the Kaa2 can handle the vast majority of the winter heat load and needs to be helped a small portion of the time using a backup fuel already in place ,that is an ideal situation.It is the undersizing of a coal boiler when no existing backup system is able to help out if necessary that could become a costly error.At the very end of this spring I ran this unit about #135 worth and have it somewhat dialed in but will have a few more questions when I bring it on for real this fall.Thanks for the advice. Mike