Heating with Coal Furnaces
While few homes in the US burn coal for heat these days, it is still used by many industries, such as steel and cement plants. Natural gas and oil are preferred fuel sources because they burn more cleanly. In the year 2000 there were only about 140,000 coal furnaces in use in private homes.
Coal Furnaces and Boilers
Coal furnaces contain fumes within a sealed steel box. Heat exchangers extract the warm air and vent it through the same heat distribution systems that other types of furnaces use. Replacing coal furnaces, coal-burning boilers are now preferred for central heating. Manufacturers claim this type of heater runs 50% more efficiently than older coal-burning furnaces and also heats the hot water supply for the household. The following manufacturers sell coal-burning furnaces:
Drawbacks of Using Coal
Deadly fires frequently break out below ground in coal mines, and there is no viable way to extinguish them. These fires don't just destroy the coal; the smoke, sulfur, and carbon dioxide gases they release pollute the air. The fires also kill vegetation above ground. Underground coal fires in China destroy more coal than miners extract in that country. Some fires in the US are still burning after decades.
Coal is also a resource that is running out. Some experts claim there is only enough coal left worldwide to last about 150 years. Despite these drawbacks, in some parts of the world, coal is still a major heat source. In China and many other countries, people still burn coal in poorly ventilated and inefficient stoves. The health repercussions can be deadly.
Improvements in Coal Heating
Not all the news regarding coal is negative. Researchers interested in coal use are working on correcting its polluting properties. Their work also includes finding ways to preserve the coal supply so it will last longer. There is ongoing worldwide exploration to find new areas of coal deposits. Inventors are also creating more efficient appliances for burning coal.
Origins of Coal
Vegetation trapped between layers of rock turns into coal via underground heat and pressure. The process takes millions of years, which is why coal is designated as a non-renewable resource. Coal is a long-lasting fuel source because it contains hydrogen, oxygen, and carbon.