Potterton Osprey CF 125, Installation & Service Instructions Manual, Page: 7 / 30

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.
Open Flue
Boiler In Room
Table 1
Combustion Air
Model Output kW Free Area cm²
Osprey 125 35 163
Osprey 150 43 208
Table 1a
Combustion Air - High and Low Level
Model High Level cm² Low Level cm²
Osprey 180 281 562
Osprey 220 315 630
Open Flue Boiler Compartment
Ventilated From Inside
O
S
P
R
0
1
7
A
Table 2
Compartment Ventilation - Free Area
Model High Level cm² Low Level cm²
Osprey 125 388 776
Osprey 150 478 958
Fig. 3