
13
Products of
combustion to
ventilated area
Fresh
Air
Products of
combustion
Firing
tube
A Forced
Burner
B Heat
Exchanger
C 4ins
Clips
D
4ins Flexible Vent
E
4ins Flexible Vent to Fan
F
Shroud for unvented heater
installation
if heaters are installed with no vent the
ventilation instructions detailed in section
1.8 must be applied.
Ducted air must be used in locations
where there is airborne dust or where
there is a polluted atmosphere e.g. Chlorinated
Vapours.
Maximum length = 25ft
Minimum diameter = 4ins
Maximum no of bends = 2
Option 2 - Figure 8.f. Forced Burner with Heat Exchanger (No External Venting)
For ducted air and products of combustion to ventilated area