The difference between an open and a closed chamber in gas boilers.

Gas boilers are available in two common versions - with an open chamber and a closed chamber. What are both types of device?

What is a gas boiler with an open chamber?

Gas boilers of this type, also called natural draft devices, function by using atmospheric air as a source of oxygen for combustion. Thus, it is taken from the room where the boiler is installed, in the required amount due to natural draft, which is formed due to the movement of air from the premises to the outside.

Gas boiler with an open chamber

Combustion products in devices of this type are removed through a special chimney: its presence in the boiler structure is mandatory. This can somewhat complicate the installation of the unit in residential premises: good ventilation must function there, otherwise the operation of the boiler due to the active use of air can negatively affect the health of people in the rooms.

It is therefore recommended to install gas boilers in special rooms located in those parts of the building that are at a sufficient distance from living rooms. These premises must comply with established safety standards. Chimneys are also installed in them.

Open chamber boilers are fairly easy to maintain. They are relatively inexpensive. An alternative to them can be units with a closed combustion chamber. Let's study their features.

What is a closed chamber gas boiler?

Boilers of this type also use atmospheric air for gas combustion. However, the combustion products of the considered units are removed not through a traditional chimney, but through a coaxial one. This is possible thanks to the horizontal smoke extraction function. The coaxial chimney is easier to install than the traditional one. Air intake from the atmosphere is carried out by a special fan, and the action of natural draft is not used.

Gas boiler with a closed chamber

The advantage of boilers of this type is that, unlike units with an open system, it is not necessary to install them in special rooms, if necessary - it is possible in residential. True, the rooms should have a sufficient area, since a gas boiler is a very voluminous unit.

The main structural element of the fan, which removes the smoke generated in the boiler, is the electric motor. Therefore, the room in which the gas boiler is installed must also have a free socket.


The main difference between an open chamber and a closed one in gas boilers is that the first structural element of the unit operates by natural draft and involves the removal of combustion products through a traditional chimney installed in a special room. Desirable - located at a distance from living rooms.

The second type of chamber in gas boilers involves directing air from the atmosphere into the unit using a fan, and also provides for the removal of the resulting smoke. As a result, combustion products can be removed by means of a coaxial chimney. It has a less complex design, as a result of which the boiler of the type in question can be installed in residential premises.

Having determined what is the difference between an open and a closed chamber in gas boilers, we reflect the conclusions in a small table.


Open chamber in the gas boiler Closed chamber in the gas boiler
Operates by using natural draftDoes not use natural draft as air from the atmosphere is directed to the boiler by a fan
Assumes the removal of gas combustion products through a traditional chimneyAssumes the removal of gas combustion products, reduced in volume due to the removal of the resulting smoke, through a coaxial chimney
Boiler with an open chamber should be installed in a special room - where it is possible to install a traditional chimney, in many cases it is desirable to locate it at a distance from living roomswhich directs air into the chamber and dissipates emits smoke in the unit, to the socket)