1403BSHH_AMEN,page 7/29
5.2 Duct
connections
The air heaters are designed to be used in conjunction with
intake and or discharge ducting. A positive seal should be
made between any ducting and the air heater. A flexible
connection is desirable to eliminate transmission of noise
and to take account of thermal expansion. Figure 5
illustrates a method of connection between the appliance
and the duct using a proprietary patented connection
system.
Consideration should be given to the application of duct
fittings directly connected to the appliance. Air inlet and
outlet elbows, transitions etc. should be designed to ensure
an unrestricted and turbulent free air flow. This requirement
is to ensure that an even air temperature is maintained
when leaving the appliance thus eliminating heat exchanger
"hot-spots" and nuisance shut-down of the burner due to
over heating.
Figure 4 : Recommended procedure and method for connection of ducting and transitions to the air heaters using
a typical proprietary flange system.
1 Corner jointing framework
2 Cleats between sections to be joined
3 Fastening through all members
4 Checking alignment and joint worthiness
5 Applying gasket seals to prevent air leakage
6 Sectional view of completed joint
COMBUSTION AIR SUPPLY & FLUE SYSTEM
6.1 General
6.1.1 Flue
requirements
IMPORTANT
The flue must be installed in accordance with
national and local regulations. Failure to provide
proper flueing could result in death, serious
injury and/or property damage. The air heater
must be installed with a flue to the outside of the
building. Safe operation of any power vented gas
apparatus requires a properly operating flue
system, correct provision for combustion air and
regular maintenance and inspection.
Model BSHH heaters may be installed as Type-B and
Type-C installations.
Flue must be in accordance with BS6230 or BS5440.
Local requirements may apply in addition to national
requirements. These unit heaters are designed to
operate safely and efficiently with either a horizontal or
vertical flue system when installed with the specific
requirements and instructions.
If this heater is replacing an existing heater, be sure that
the flue is sized properly for the heater being installed
and that the existing flue is in good condition.
6
Cut and assemble flange
into frame to suit opening
Check dimensions and
position on duct spigot.
Ensuring flange is mated
correctly before fastening.
Checking location after
positioning.
