Technical data

15
operation should mechanical air
supply fail for any reason
The table below provides specific data for
each heater model as -
2.5 Flue Installation.
An integral flue spigot is fitted to all Variante
Air Heaters thereby allowing the flue to
connect directly to the heater.
The design of the flue must ensure that it
can be disconnected to allow for cleaning
and servicing.
All joints should be sealed between the
sections.
Warning
It is essential that the products of
combustion are flued to the outside of the
building.
Each heater must have its own separate
flue, with a flue diameter of not less than is
detailed in section 7.2 within this manual.
WARNING
On VRA 60 to 120 installed in flue only
option (type B appliance) - a combustion
air grille is supplied as standard. This MUST
be fitted in place of the combustion air
spigot.
On VRA145 ONLY installed in flue only
option (type B appliance) - a combustion
air grille is supplied as standard. This MUST
be mounted on the top of the unit replacing
the blanking plate. The blanking plate is
then fitted in place of the combustion air
spigot.
The flue assembly must comply with all the
relevant regulations regarding height and
materials, and must terminate with an
approved flue terminal.
Care should be taken to ensure that the flue
terminal is not situated in a high pressure
area, the proximity of buildings and other
obstacles which will influence this must be
taken into account, preferably at the design
stage.
All Variante Heaters are equipped with a
built in flue venter fan which prevents the re
-circulation of combustion products,
consequently an external draught diverter,
barometric damper, or anti spillage system
must not be installed. Such devices are
unnecessary on the BVA/C range of
heaters.
Horizontal flue installations:
Distance from heater connection to
terminal must not exceed the following
length-
12kW 3 Metres
20/60kW 6 Metres
72/145kW 8 Metres.
Each 90
°
bend corresponds to 1m of flue
length.
Each 45
°
bend corresponds to 0.8 m of flue
length.
Flue pipe should be supported at intervals
not exceeding 1.8 m.
In order to provide adequate natural
draught, the minimum length of horizontal
flue must not be less than 1m.
MODEL
Mechanical Ventilation
Rate for Plant Room or
Enclosure
M
3/
h
12
54
20
88
30
133
42
177
50
221
60
265
72
327
95
436
120
543
145
652