The Great Mystery…Explained

What makes a fire burn? Why do some fires in your fireplace burn longer and hotter than others? The one word answer: science. Fire is a chemical reaction that produces heat energy. This complex sequence of chemical reactions in which a fuel reacts with the oxygen in the air is known as combustion. As soon as that oxygen is used up, these chemical reactions begin losing steam and ultimately cease altogether.

The Fire Triangle Explained

Fire requires all three of these elements to burn properly. Too much or little or any can cause significant problems for performance.

Fire requires all three of these elements to burn properly. Too much or little or any can cause significant problems for performance.

Three things are required in proper combination before ignition and combustion can take place: heat, oxygen and fuel. This is often referred to as the fire triangle. There must be fuel to burn, air to supply oxygen, and heat to start and continue the combustion process. With a continuous supply of heat (which is a product of the combustion process itself), the ignition of additional fuel will continue as long as there is sufficient oxygen present.

If any one of the three sides of the fire triangle is removed, the fire will cease to burn. Weaken any one or more of the sides, and the fire will weaken. Increase any one or more of the sides, and the fire will increase in intensity. This knowledge helps firefighters manage and extinguish fires; why shouldn’t homeowners make use of it, too?

Getting the Most out of Combustion

The goal, as far as combustion in concerned, is to retrieve energy from the burning of fuels in the most efficient way possible. To maximize the efficiency of the combustion process, it is necessary to burn all fuel material with minimal losses. The more efficiently a fuel can be burned and its energy gathered, the cheaper the combustion process then becomes.

Complete combustion occurs when 100% of the energy in the fuel is extracted. There must be enough air in the combustion chamber for complete combustion to occur. The addition of excess air greatly lowers the formation of carbon monoxide (CO). The less CO remaining in the flue gas, the closer to complete combustion the reaction becomes because the CO still contains a significant amount of energy that can and should be completely burned.

Getting a more solid grasp on the combustion process and how to maximize its effects will better prepare homeowners to get the most bang for their heating bucks. This will also reduce the amount of creosote and other chemicals that can build up on the inside of your chimney. An annual chimney cleaning and inspection by a CSIA-certified chimney sweep is still recommended, however, as even a small amount of these substances is enough to cause a dangerous and potentially deadly chimney fire. We hope that you have found this material to be both informative and enlightening.