How does a gas fire combustion system work?

For all fires and stoves, a distinction is made between an open combustion and a closed combustion system. For every kind of combustion, whether it is wood or gas, oxygen is required to enable combustion to take place. Open combustion systems extract the necessary oxygen from the room itself and, in the case of closed combustion systems, the oxygen is extracted from the outside.

Combustion systems for gas fires and gas heaters

All gas fires and gas heaters will have an open or closed combustion system.

Gas fire with open combustion

A gas fire with an open combustion system can have the appearance of a fire, but also occur behind a glass door. Open combustion occurs when the air for the combustion is directly drawn from the surrounding space. A gas fire with open combustion cannot be used in just any home. A gas fire in the form of an open fire has low efficiency. An open gas fire only creates an atmosphere and generates very little heat.

For open gas heaters, the output is slightly higher, but this is certainly not sufficient. An open gas fire cannot be used in a house that is equipped with mechanical ventilation, a system that is present in many contemporary homes. For instance, the use of an extractor hood in an open kitchen is not safe. Gas fires with an open combustion system are hardly ever used due to these limitations and for safety reasons.

1. Oxygen supplied from the living area 2. Flue gas outlet through the chimney

Gas fires with closed combustion

In almost all contemporary gas fires and gas heaters, a closed combustion system is used if possible. The fire or stove is connected to an outlet with two ducts. The innermost pipe removes the flue gases. The surrounding, outer pipe transports the oxygen for combustion. Gas fires with closed combustion have several advantages:

• Gas fires and heaters with a closed combustion system are very safe in modern, well-insulated homes.
• A flue gas fan is not necessary.
• The inside of the fire reaches a higher temperature and combustion therefore takes place with greater efficiency. Contemporary gas fires and gas heaters are high-efficiency appliances.

This type of combustion system does not necessarily require an existing chimney. Obviously, it is possible to use existing channels, but it is also possible to opt for a different location in the home.