VENTILATION INFORMATION
VENTILATION INFORMATION
Conventional flue boilers require an adequate supply of fresh air which must be delivered to the boiler
for combustion purposes through a permanent inlet, such as an air brick, into the area where the
boiler is situated.
If a cupboard or compartment which is to be used for storage or airing is built around the boiler after
installation there must be a non-combustible partition around the boiler. Further information can be
found in BS 5410 which also describes venting requirements.
Conventional flued boilers:
Minimum area of of air inlet for combustion:
MINIMUM AIR VENT AREA (cm
2
) FOR BOILERS INSTALLED IN A COMPARTMENT:
1Internal air to and from a space/room inside the building. 2External air to and from directly outside the building.
Venting compartments:
Ventilation must be provided for boilers fitted into compartments as described in BS 5410
A minimum of two air vents must be fitted, one at low level and another at high level onto the
same wall using the same air for circulation.
Combustion air must not be taken from a room or internal space containing a bath or shower and
must not communicate with a protected area such as a hall, stairway, landing, corridor, lobby,
shaft etc.
Air vents must allow access for clean free air and must be sited to comply with the flue
terminal position requirements.
Air ducting runs must not exceed 3m.
Low level air vents must be less than 450mm from the floor.
A warning label must be attached to the vents with a statement to the effect:
''Do not block this vent.
Do not use for storage''.
Conventional flue
kW
Internal
1
ventilation External
2
ventilation
High
Level
Low
Level
High
Level
Low
Level
12/18
198
279
99
198
18/25
275
413
138
275
25/32
352
528
176
352
kW
Area (cm
2
)
12/18
99
18/25
138
25/32
176
Room Sealed flue:
kW
Internal
1
ventilation External
2
ventilation
High
Level
Low
Level
High
Level
Low
Level
12/18
198
198
99
99
18/25
275
275
138
138
25/32
352
352
176
176
GREENSTAR HEATSLAVE 12/18 - 18/25 - 25/32
8 716 106 253f (03.2010)
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