Technical data

0803UDSA-2GBEN, Pag. 8/36
7. Flue
requirements
Model UDSA-2 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. A
properly sized flue system is required for safe operation of the heater. An improp-
erly sized flue system can cause unsafe conditions and/or create condensation.
The air heaters may be installed as a balanced flue (type C) heater requiring both a
combustion air inlet duct and a flue pipe or as a power vented heater (type B) (the
combustion air is taken from the space where heater is installed), which requires
only a flue pipe exhausting to outdoors.
All products of combustion must be flued to outdoor atmosphere.
Each heater installed as a type B appliance must be fitted with an individual flue
pipe and the combustion air inlet opening is provided with a protection grill. Each
heater installed as a type C appliance must be fitted with an individual combustion
air/flue pipe system. Type C2 appliance, with single duct system for supply of
combustion air and evacuation of flue gasses, are not allowed.
Flue pipe diameters and maximum pipe lengths in table 5 apply to both horizontal
and vertical systems. Add all straight sections and equivalent lengths for elbow.
The total combined length must not exceed the maximum flue length.
Diameter & maximum
flue pipe lengths
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 regu-
lar maintenance and inspection.
Table 5 : maximum flue system pipe lengths
flue pipe 80 100 130
inlet pipe 80 100 130
flue pipe 9 9 9
inlet pipe 9 9 9
flue pipe 0.75 0.75 0.75
inlet pipe 0.75 0.75 0.75
flue pipe 1.5 1.5 1.5
inlet pipe 1.5 1.5 1.5
Heater socket & p ipe dia
m
025-2
Æ
050-2 055-2
Æ
100-2
Equivalent length of 90° elbow
Model UDSA 008-2
Æ
020-2
m
m
Max. straight length (with wall/roof
terminal)
Equivalent length of 45° elbow
mm
• Use only one diameter of flue pipe on an installation.
• Recommended minimum flue is 1m.