8
xtra
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Installation & Servicing
GENERAL
3
VENTILATION
The ventilation requirements of these boilers are dependant
on the type of flue system used, and their heat input. All vents
must be permanent with no means of closing, and positioned
to avoid accidental obstructions by blocking or flooding.
Detail reference should be made to BS. 6644 for inputs
between 70kW and 1.8MW (net). In IE refer to the current
edition of I.S.820. The following notes are for general
guidance only:
Dust contamination in the combustion air may cause
blockage of the burner slots. Unless the boiler room
provides a dust free environment then direct connection of
the air intake via ducting to clean outside air should be used.
The temperature within a boiler room shall not exceed 25
o
C
within 100 mm of the floor, 32
o
C at mid height and 40
o
C within
100 mm of the ceiling.
IMPORTANT NOTE.
If combustion air is drawn from within the boiler room,
ensure no dust or airborne debris can be ingested into the
appliance. Dusty concrete flooring should be sealed to
reduce the presence of dust. Ideally where possible duct
the air supply into the boiler room from a clean source
outside the boiler room/building.
Open Flued Installations
If ventilation is to be provided by means of permanent high and
low vents communicating direct with outside air, then reference
can be made to the sizes below. For other ventilation options
refer to BS. 6644. In IE refer to the current edition of I.S.820.
Required area (cm
2
) per kW of total rated input (net)
Boiler Room
Enclosure
Low level (inlet)
4
10
High level (outlet)
2
5
Note: Where a boiler installation is to operate in summer
months (e.g. DHW) additional ventilation requirements are
stated, if operating for more than 50% of time (refer to BS6644).
Room Sealed Installations
A minimum of 2cm
2
free area per kW of net heat input at both
high and low level is required for boiler rooms. For enclosures
refer to BS6644.
2
BOILER CLEARANCES
The minimum dimensions as indicated must be respected
to ensure good access around the boiler.
Recommended minimum clearances are as follows.
Rear:
700mm or adequate space from the rear of the jacket to
make the flue connections and access to the flue sample
point, drain connection, flue and any safety or control devices.
Left Side:
450mm
Right Side:
150mm
Front:
600mm; except, access doors may be closer, but not
less than 200mm and 600mm must still be available
for service across the width of the boiler.
Top:
500mm.
