Technical data

means to safely inhibit heater(s)
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/C 200 to 490 a Combustion Air
Plate is supplied as standard this MUST
be fitted in place of the combustion air
spigot if the heater is to be installed in the
flue only option
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 must not
exceed the following
VRA/C 040 3 Metres overall length.
VRA/C 070/200 6 Metres overall length.
VRA/C 250/490 8 Metres in overall length.
Each 90
0
bend corresponds to 1Mtr of flue
length
Each 45
0
bend corresponds to 0.8 Mtr of flue
length
Flue pipe should be supported at intervals
not exceeding 1.8 mtrs
In order to provide adequate natural draught,
the minimum length of horizontal flue must
not be less than 1Mtr.
For vertical flue installations the flue should
rise vertically where possible bends should
not exceed 45
0
and the number of bends
should be kept to a minimum.
Maximum vertical flue length must not
exceed 10 Metres
The temperature of the combustion products
can be as high as 170
0
C and therefore tend
to rise naturally within the flue. Unnecessary
bends and restrictions should therefore be
avoided.
MODEL
Mechanical Ventilation
Rate for Plant Room or
Enclosure
M
3/
h
40
54
70
88
100
133
135
177
170
221
200
265
250
327
330
436
410
543
490
652