Post
by Berlin » Mon. Feb. 01, 2010 2:21 am
As I've said before anthracite is a good coal to use, it has less variability, no visable smoke in a hand-fired appliance, and there exists a variety of appliances on the market designed specifically for its combustion. Having said all that, in many cases bituminous coal is an excellent choice. It has higher btu's, less ash, and with good coals can be easier to use in certain appliances.
Greg, while many stoves do not thoroughly combust the volitile matter, they usually manage to combust a large portion of it, at least partially. This, I believe, is enough to bring the usable btu's/lb to at least the level of anthracite's average, and, depending on the coal and appliance, probably higher. Don't forget that while dampering down anthracite you lose combustion efficiency in the form of large amounts of CO; when both bituminous and anthracite are operating at high burn, I believe the usable BTU's in bituminous will easily exceed that of anthracite, determined, obviously by the BTU's over anthracite in the bit coal. As far as finding a bituminous boiler that will not have to be tended for days at a time, you are right, there isn't much on the market. Any bituminous "clinkering" stoker will have to be tended at least once/day when demand is high, and at least every other day when demand is lower. There are some stokers now available that will allow multi-day and longer use without attention. These are the rotating ring stokers such as the coal-man etc. with bin feed and ash augers; those stokers will require a low coke button coal, less than 4. While the majority of eastern coals have coke-button's higher than 4, with relative ease coal can be found in every eastern state that will deliver a coke button of 4 or lower. As Interest in heating with coal continues to grow, I believe there will be more GOOD options for heating with bituminous coal.