3 January 2022

The Fire Triangle: Fuel, Oxygen & Heat

What is the Fire Triangle?

The fire triangle is based upon the 3 key components required to ignite and maintain a fire; Fuel, Oxygen and Heat.

When lighting and keeping your fire burning, you need to ensure the fire triangle is maintained. If one of these elements is removed, the fire will diminish and eventually extinguish itself. Likewise, if one of the elements is not present when trying to start the fire, the fire will fail to light.

Fuel

A fire cannot ignite without combustible material. In terms of lighting a fire, the fuel is initially a firelighter and maintained with logs. You should start with kindling and some smaller logs as these have a lower burn point than bigger logs. As the fire progresses you can add larger logs. Without enough fuel, your fire will struggle to maintain the burn. It is crucial that you have enough logs on the fire to provide the fuel element of the fire triangle.

Oxygen

Oxygen is required to allow the combustion reaction to occur and for heat to be released. The best way to regulate oxygen levels in your woodburner is to utilize the air vents. When you are lighting the fire, you need more oxygen than once the fire is hot and burning well. To achieve this, make sure your air vents are fully open when lighting the fire. You can also keep the door/s ajar to let more air in.

Once burning, you can close the doors and adjust the air vents as required. Bear in mind, that whilst less oxygen is required to maintain the fire, it still requires some oxygen. The air vents should only be fully shut down if you want to extinguish the fire.

If you are burning in an open fire and are struggling to get enough oxygen to start your fire, a bellow can help!

Heat

Initially the heat for your fire will come from the match, which you light your firelighter with. Firelighters should be used over other flammable products as they are specifically designed to help light the fire safely. Starting your fire with paper or newspaper should be avoided. Paper doesn’t provide as much heat as firelighters or burn for as long, making it difficult to start your fire as the heat is removed from the fire triangle. Burning paper can also increase the risk of chimney fires as flakes of ignited paper can float up the chimney where residual creosote lies.

After the initial input of heat from the firelighter, the heat is maintained by burning multiple logs against each other. If you only put one or two logs in your fire the heat will slowly subside, especially if you are burning denser wood such as ash. For extra heat bits of wood can be added to the fire.

How do I get the fire to die down?

If you want to let the fire die down before you go to bed or go out, you need to remove at least one component of the fire triangle. The easiest way to do this is to stop adding logs and to close the air vents right down. The result won’t be instant but will slowly burn out.