0108X1DHGBEN
6
SECTION 3 INSTALLING
3.1 When installed as an in-line duct heater i.e. not fitted
within an air handling appliance cabinet it is necessary
to ensure that clearance is maintained around the
appliance from combustible materials and for service
access. The clearances necessary to ensure safety for
combustibles is 150 mm on all sides. Service access
should be allowed on the controls side of the
appliance equal to the dimensions given in table 3 this
distance allows for the removal of the burner tray
assembly, necessary when servicing the appliance.
3.2 Ensure that the structural elements which will be used
to suspend or support the appliance, are adequate to
carry the weight of the appliance and its ancillary
components i.e. flue system and any dependant duct-
work.
3.3 Ensure that the air heater is installed in a level plain
both laterally and horizontally.
3.4 If the air heater is to be base mounted in an open
position then it must be secured to the floor or other
supporting device/s.
3.5 4 suspension brackets with holes
φ
10.5 mm are
available as optional accessories.
Use 10 mm
φ
rods for suspending the heater when
using these Reznor options.
3.6 If the appliance is to be suspended or base mounted
from cantilever brackets, specially designed wall
brackets should be manufactured to suit the
application respecting the clearances indicated in 3.1
above and the live load factors the appliance and it's
air handler will impose.
3.7 After suspension, the air heater should be rigid so as
to avoid placing a strain on the flue system, gas
services, electrical wiring and duct system.
3.8 Euro-X 1000 D series air heaters, wether or not they
are installed within an air handling appliance may be
installed in multiple form as illustrated in figure 4. In
all instances the air flow passed through the
appliance/s should not exceed the volumes required to
ensure that dew point conditions within the
combustion circuits/s as indicated in figure 3 do not
occur.
By-passes should be constructed as necessary to
ensure that the optimum temperature rises are met
taking into account the pressure resistance of the air
heater as indicated in figure 2.
When designing by-pass ducts ensure that the
requirements for service access, flue and
controls connections are maintained. An adjustable
damper should be included within by-pass ducts to
enable air flow pressure and volume to be adjusted
after installation.
When fitting Euro-X 1000 D air heaters in a side by
side configuration it is necessary to specify this
requirement when ordering type D models. Opposite
handing of the appliances may be required. Whilst the
air may be passed through the appliance from either
end, provision for locating the thermal over-heat
(limit) control device has to be made so that the air
off side (the hottest side) is monitored for this
purpose. Further to this the flue down draught spillage
slot (normally at the front air discharge side of the
appliance) must not become obstructed with another
air heater or air ducting. A distance of 200 mm must
be maintained for flue products to freely spill.
3.9 Figure 5. illustrates the recommended principle that
should be used for the connection of ducting or air
handling appliance element transitions.
A positive seal must be maintained between the air
circuit and the air heater, this is particularly important
when the air heater is installed within an air handling
cabinet. A neutral pressure zone around the appliance
must be maintained to ensure that the atmospheric
burner operates at all times at normal ambient
pressure.
3.10 Figure 6 illustrates some of the situations to be
avoided when connecting an air handler to the
appliance. A rule of connecting a straight length of
ducting equal to 3 times an equivalent duct diameter
onto the appliance should be maintained whenever
possible. It is essential that an even air flow is
distributed across the heat exchanger to ensure that
the heat is scrubbed from all the exchanger elements
thus preventing hot spots which will greatly reduce
the working life of the air heater and nuisance burner
shut-down through over heating may occur.
Always avoid installing a centrifugal fan so that the
swirl effect created by the direction of rotation is
counter directive. As well as the effect of uneven air
flows, excessive loss of static pressure is created
resulting in inefficiency of the fan.
Where it is necessary to connect a transition section
as part of the connection then the degree of taper in
any plain should not be greater than 15
°
. Abrupt
transitions create eccessive pressure drops and lead
to uneven air distribution across the air heater.
3.11 Adequate clearance from combustible materials must
be maintained between the appliance and its flue
system.
3.12 EURO-X air heaters are open flued natural draught
appliances, it is therefore, important that they are
installed in a draught free zone i.e. away from doors
etc. Consideration must be given to the effects that
any power extraction might have on the buildings
natural pressure condition. The appliance flue will act
as a pressure relief in the event that a negative
pressure exists within the space where the air heater
is installed.
Extract systems must be electrically interlocked with
the air heater controls.
