Air Supply - Potterton Osprey CF 125 Installation & Service Instructions Manual

Installation Requirements - Page 7
Conventional Flue Models

1.4 Air Supply

The air requirements must meet BS 5440 Part 2 & BS 6644.
The room in which the boiler is installed must be ventilated.
Ventilation of the room containing the boiler shall include air
for combustion and correct operation of the flue (ie Draft
Diverter dilution).
A permanent air vent shall be provided in an outside wall of
the building either at high or low level in accordance with
Table 1 - Osprey 125 & 150 Only. The Osprey 180 & 220
must have high and low level vents in accordance with Table
1a.
The opening may be:
a) Directly into the room or space containing the boiler
(all models) or indirectly via an opening of at least
the same area (125 & 150 models only).
b) Via a duct either directly into the room or space (all
models) or indirectly via an opening of at least the
same free area (125 &150 models only).
Where air is drawn indirectly from outside through more than
two air vents refer to BS 5440 Part 2 - Osprey 125 &
models150 only.
Where an extraction fan is fitted in the room containing the
boiler, special ventilation requirements must be
implemented. Refer to BS 5440 Part 2 and BS 6644.
Any grille and/or duct should be so sited and of a type not to
become easily blocked or flooded and should offer low
resistance to airflow.
If the boiler is installed in a compartment, permanent air
vents are required in the compartment, one at high level and
one at low level (Table 2), either direct to the outside air or to
a room Osprey 125 & 150 Only. The Osprey 180 & 220
cannot be installed in a compartment except those specified
in BS 6644 using a monodraught system. Both high level
and low level air vents must communicate with the same
room or must be on the same wall to outside air (125 & 150
models only).
Ensure that all air inlets and outlets are always completely
free from obstruction.
Boiler In Room
Table 1
Combustion Air
Model Output kW
Osprey 125 35
Osprey 150 43
Table 1a
Combustion Air - High and Low Level
Model High Level cm²
Osprey 180 281
Osprey 220 315
Open Flue Boiler Compartment
Ventilated From Inside
Table 2
Compartment Ventilation - Free Area
Model High Level cm²
Osprey 125 388
Osprey 150 478
Fig. 3
Open Flue
Free Area cm²
163
208
Low Level cm²
562
630
Low Level cm²
776
958