HAMWORTHY HEATING LTD
50
FLEET V series
500001217/D
Figure D1 Mechanical Ventilation Flow Rates
Flow rate per kW
total rated heat input (Net)
Inlet air
(Combustion
ventilation)
Difference between
Inlet & Extract air *
m³/h.
m³/h.
Volume
2.6
1.35
Note * : Where the associated air extraction is also by means of a fan, this shall be selected such as not to
cause a negative pressure to develop in the boiler house and to maintain the difference between inlet and
extract flow rates shown above.
The calculated extract flow rate is the actual inlet flow rate minus the appropriate figure in the table above.
D 1.4. Boiler House Temperatures
The air supplied for boiler house ventilation shall be such that the maximum temperatures within the boiler house
shall be as follows:
At floor level (or 100mm above floor level) = 25°C.
At mid-level (1.5m above floor level) = 32°C.
At ceiling level (or 100mm below ceiling level) = 40°C.
D 1.5. General Requirements
The air supply should be free from contamination such as building dust and insulation fibres from lagging. To
avoid unnecessary cleaning and servicing of the boiler modules, the boilers should not be fired whilst building
work is being undertaken.
High and low level ventilation grilles shall be positioned as high and as low as practicably possible. Low level
grilles should be located within 1 metre of the floor for Natural Gas. High level grilles should be positioned within
15% of the boiler room height from the ceiling. High and low level grilles shall communicate with the same room or
space where compartment ventilation is used. Where grilles communicate directly with outside air, they shall be
positioned on the same wall.
