Technical information

Position ventilation grilles to avoid the risk of accidental obstruction by blocking or flooding. BS
5540.2
Table 12 Ventilation
Vent Position Into room or internal space Direct to outside air
High level 9 cm
2
per kW of input 4.5 cm
2
per kW of input
Low level 9 cm
2
per kW of input 4.5 cm
2
per kW of input
In a room or internal space None required None required
Conventionally flued appliance
Vent Position Into room or internal space Direct to outside air
High level 9 cm
2
per kW of input 4.5 cm
2
per kW of input
Low level 18 cm
2
per kW of input 9.0 cm
2
per kW of input
Any air vent, which is to supply air to an
open flued appliance, must not
communicate with any room/space
containing a bath or shower or private
garage.
If further guidance on ventilation is required
then consult BS. 5440.2.
Detailed recommendations for air supply
requirements are given in BS.5440.2. and
can also be found in the CORGI Gas
Installer Manual. The following notes are
intended for general guidance only. Where
open flued appliances total input ratings
exceed 7 kW the room or internal space
containing them must have an air vent of
minimum effective area 4.5 cm
2
for every 1
kW in excess of 7 kW.
17.3 Compartment Ventilation
Due to the low standing losses
compartment ventilation is not required.
EC 25 Compact Installation/User Manual page
29