| If you burn coal on sand or just ashes from a previous | | | | Consider burning on a heavy cast iron grate with an |
| fire, it would be nearly impossible to burn. Coal requires | | | | adequate amount of air available to the firebox from |
| air under the fire or it will not ignite. Wood will burn | | | | below the grate, regardless of what type of wood or |
| without a grate but very imperfectly. There is a small | | | | coal burning appliance that you choose. Adequate air |
| amount of oxygen (air) in wood. Just enough to make | | | | under the grate helps assure you of a reasonably |
| a smoldering fire to create a great deal of creosote | | | | clean fire with reduced smoke or creosote coming |
| and smoke in your heating appliance, smoke pipe and | | | | from the flame. A wood fire will last a little longer |
| chimney. To burn wood or coal on sand or just plain | | | | without a grate at the cost of a dirty fire and more |
| steel is similar to burning garbage in a barrel. If you | | | | smoke and creosote build-up on every part of your |
| ever try it you will have a very smokey fire because | | | | wood or coal burning system, including the firebox, |
| there will be a lack of oxygen (air). Unless you cut | | | | smoke pipe and chimney. |
| some holes at the bottom of the barrel. Many | | | | If you want an even cleaner fire with less creosote |
| outdoor boilers use this (non) technology. That is one | | | | and soot buildup in the system, provide a secondary air |
| of many reasons why they smoke so much. | | | | source above the flame. This is known as secondary |
| To prove the above theory to your satisfaction, you | | | | air. If you provide 80% of the air from below the grate |
| can try the following if you have a wood-burning | | | | and 20% of the air from above the flame, you can |
| fireplace. Remove the grate. Start a wood fire on | | | | increase the efficiency of the wood burning appliance |
| the firebrick or steel hearth. It’s not only hard to | | | | by as much as 40%. This is because 40% of the |
| get burning, when it does start to burn, the flame will be | | | | energy produced by a wood or coal fire leaves the |
| uneven across the wood and it will be a smoky | | | | initial flame in the form of unburned gases. By igniting |
| flame. For a second test, place the wood in a steel | | | | these gases, you not only get a cleaner burn with less |
| box with only the top open. That will cause even | | | | soot and creosote, the efficiency of the wood or coal |
| worse results than the first test. Now place the | | | | is increased dramatically, thereby stretching your |
| wood in a fireplace-designed grate. Nice fire, right? It | | | | savings on the purchase of wood or coal. |
| is because you have provided air under the grate. | | | | |