
10
Low level
540 cm
2
plus 4.5 cm
2
per
(inlet)
kilowatt in excess of 60 kW
total rated input (gross)
The actual minimum effective areas of the air vents required are as follows:
BOILER MODEL
POSITION
AREA OF VENT
OF AIR VENT
(Air direct from outside)
High Level
567 cm
2
per boiler
Regency 4 Modulek-152
Low Level
1133 cm
2
per boiler
High Level
615 cm
2
per boiler
Regency 4 Modulek-169
Low Level
1230 cm
2
per boiler
High level
663 cm
2
per boiler
Regency 4 Modulek-186
Low Level
1326 cm
2
per boiler
High level
709 cm2 per boiler
Regency 4 Modulek-203
Low Level
1418 cm
2
per boiler
High level
757 cm2 per boiler
Regency 4 Modulek-220
Low Level
1514 cm
2
per boiler
High level
808 cm
2
per boiler
Regency 4 Modulek-237
Low Level
1615 cm
2
per boiler
High level
856 cm2 per boiler
Regency 4 Modulek-255
Low Level
1712 cm
2
per boiler
High level
907 cm
2
per boiler
Regency 4 Modulek-272
Low Level
1813 cm
2
per boiler
2.4.2
AIR SUPPLY BY MECHANICAL VENTILATION
Mechanical ventilation systems serving the area containing the boiler should be designed
with an extraction air rate of 0.45 m
3
/sec per 1000 kW total rated input, and an inlet air
rate of 1.1 m
3
/sec per 1000 kW total rated heat input.
Systems employing an extract fan only must not be used, whereas the use of a single inlet
fan, or an inlet together with an extract fan is acceptable.
All air inlet and extract fans should be electrically interlocked to cause safety shut-down
or lock-out of the boiler in the event of malfunction of either fan.
The requirements of mechanical ventilation schemes is fully outlined in BS.6644.