fgb5 wrote:I am going to try the pea. Do you get longer burn times? I run my stove at a surface temp of 500-600. If I run it any lower I get clinkers as well as a cold house. But at 500-600 I go thru a bag and a quarter a day. I believe that this is tipical?
My burn times are about the same for nut or pea. A big factor in this is the Vigilant's thermostatic air control. A 700* stove in balmy 40* outdoor temperatures is the same 700* stove when it's 20 and breezy outside. Mainly, fuel usage and BTU output varies if the draft is consistent. It really doesn't seem to matter in my set up. Pea generally is a little slower to light off on recharging. I think the biggest factor is coal quality. If you have good draft, you shouldn't see anything different if the coal is good quality. In a hand fed, pea will cut back on the draft because the air passages are more numerous and smaller throughout the loaded fire box. I've had bulk pea from the local yard that has varied in size. The last load was on the small side of the pea range, more like large buck, and was a little harder to light off when recharging.
Right now, I have some nut that has a nice long burn time and lower ash but is really hard to shake down with the Vigilant 2310's gentle grate action. No clinkers, almost all powder. I run at max of ~ 700* most of the main heating season. With my current coal, I'm going through roughly 50 - 70 Lbs. If the day is sunny & in the 20s, closer to 50. When it gets into the low 20s and the teens and the days are cloudy, my usage will be on the higher side and the oil furnace assists in the heating load. If you are using 40 lb bags, you're seeing about the same usage rate. Although not with this season's coal so far, I've burned as much as 80 - 90 Lbs/day but that's the extreme.
One peculiar thing is you said you see clinkers when running cool. Generally, clinkers are formed when the burning coal bed gets overly hot and the minerals fuse together, analogous to how glass is made. When I run cold (in hand fired stove), the anthracite doesn't all go to powder. I get coal ash shaped like the original piece but it's all solid ash and will crumble when I mash it. Some describe this as 'granola' ash. Check this thread
for clinker pictures.