Many look to 'lost' art of heating with coal stoves

As more and more people turn to coal stoves for home heating, they're finding that coal is a lot harder to burn than wood.

In fact, burning coal in the home is very nearly a lost art in this petroleum generation. It takes a lot more than a flick of the thermostat to get heat from a coal stove. You have to know what you're doing. What kind of coal should you burn in the stove?

Anthracite, the hardest coal, should be used for home heating. More dense than bituminous (soft) coal, it also is purer, less polluting, steadier in its burn, and virtually odorless.

Generally, the smaller sizes of coal burn better than the larger sizes because they allow more oxygen-carrying air to circulate over a greater area of exposed coal. Most air-tight, European-style coal stoves burn pea-size (9/16ths to 13/16ths of an inch) bits, although other stoves may burn nut coal (13/16ths to 15/8ths of an inch). Automatic stocker furnaces in a basement use very small rice-size coal.

Generally, the smaller sizes of coal burn better than the larger sizes because they allow more oxygen-carrying air to circulate over a greater area of exposed coal. Most air-tight, European-style coal stoves burn pea-size (916 to 13/16 of an inch) bits, although other stoves may burn nut-size coal (13/16 to 15/8 of an inch). Automatic stoker furnaces in a basement of a house use very small rice-size coal.

Generally, the smaller sizes of coal burn better than the larger sizes because they allow more oxygen-carrying air to circulate over a greater area of exposed coal. Most airtight, European-style coal stoves burn pea-size (13/16ths to 9/16ths of an inch) bits, although other stoves may burn nut coal (13/16ths to 15/8ths of an inch).Automatic stoker furnaces in a basement use very small rice-size coal.

It's important to know and follow the manufacturer's recommendations. Using too small a size may allow coal to fall through the grate and be wasted.

A coal fire will often die out because ashes have built up below and on top of the grate, thus blocking essential oxygen from reaching the coal bed. Unlike wood, a coal fire gathers about 80 percent of its oxygen from beneath the grate.

For this reason it is necessary to shake down the ashes and empty the ash pan frequently. Depending on the type of stove and the rate of burning, the grate should be shaken two to four times a day.

Clinkers, which keep the coal from getting enough oxygen, also cause fires to die.

Clinkers are the noncombustible minerals of coal that show up as lightweight fused ashes capable of forming larger and larger chunks. Whenever you shake the grate, break up the clinkers with a poker, preferably at the grate level. If possible, remove them, but remember a coal fire does not like to be disturbed.

What are clinkers? Clinkers are the noncombustible minerals of coal that show up as lightweight fused ashes capable of forming larger and larger chunks. Whenever you shake the grate, break up the clinkers with a poker, preferably at the grate level. If possible, remove them, but remember a coal fire does not like to be disturbed.

If your newly ignited coal fire dies out without ever reaching its full potential, the reason may be that you do not have enough coals together in the stove. A coal fire burns best if it is concentrated; therefore, a dispersed bed of coals doesn't burn for long.

To start a coal fire from scratch and keep it going, prepare a large red-hot bed of wood coals first. The ignition point of coal is roughly 660 degrees F., about 100 degrees higher than the ignition point for wood. Anthracite will never ignite directly from merely crumpled paper and kindling alone.

If your fire seems to be fading, open a damper or door that feeds air to the bottom of the stove. This increases the rush of oxygen up through the coals and injects new life into the fire.

In mild weather your coal fire may stall and dim to the vanishing point. All factors being equal, this may mean that the outside temperature is approaching the chimney temperature, thereby reducing the draft. This, in turn, slows down the flow of oxygen through the firebed. Opening the damper or the door that feeds the fire may rejuvenate the coals.

Coal stoves that automatically feed a fire by gravity through a hopper are easier to control and maintain. On the other hand, so-called batch-burner stoves , into which you shovel the fuel all at once, must be ''banked'' at night.

In other words, for continued nighttime burning, rake the coal forward toward the feed-door damper so that a hot red spot remains visible. Shovel in fresh coal and slant the new coal up the back and sides of the firebox. This keeps oxygen available directly to the hot coals and makes sure the carbon-monoxide exhaust is burned away safely.

If all else fails and your fire still goes out, clean out the totally extinguished coals from the firebox and start all over again - patiently and methodically.

Respect coal for what it can be--a very hot, warming fire.