0505T2D0GBEN
6/21
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 width of
the air heater plus 200 mm, this distance allows for
the removal of the burner tray assembly, necessary
en 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
connected duct-work.
3.3
Ensure that the air heater is installed in a level plain.
3.4
If the air heater is to be base mounted in an open
position then it must be secured to supporting
devices.
3.5 4 suspension brackets with holes
φ
10.5 mm are
available as optional accessories.
Use 10 mm
i
rods for suspending the heater when
using the 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 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-work.
3.8
Euro-T.. Series D 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-T.. air heaters in a side by side
configuration it is necessary to specify this requirement
when ordering type D models. 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.
3.8 Figure 5. illustrates the recommended principle that
should be used for the connection of ducts 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.
3.9
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 duct 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.
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
E
. Abrupt transitions
create excessive pressure drops and lead to uneven air
distribution across the air heater.
