18
8. FLUES AND VENTILATION
VENTILATION
As the Contractor WM70 HE is a balanced-flue appliance, the
provision of an adequate supply of combustion air is not
necessary. However, adequate ventilation is required for the
cooling of the boiler controls if the appliance is to be installed in
a compartment or confined space (see
fig 19
).
The air opening should be positioned so as to cause the least
possible draught to the occupants and located so it is not liable
to be accidentally blocked.
British Code of Practice BS 5410: Part 1 requires a permanent
air inlet opening of 550mm
2
per kW of boiler rated output
above 5kW.
The following air openings, shown on
fig 19
, are required for
the Contractor WM70 HE.
Output
Detail ‘A’ (fig 19)
50,000 Btu/h
53cm²
60,000 Btu/h
69cm²
70,000 Btu/h
83cm²
FIG 19
VENTILATION