Webasto GBW 300 Installation instructions manual - page 53
Combustion air supply
GBW 300
50
12
Combustion air supply
Under no circumstances may the combustion air be taken from areas
occupied by people. The combustion air intake opening must not point
in the direction of travel. It must be located so that it cannot become
clogged with dirt or snow and cannot suck in splashing water.
The combustion air intake must not be routed above the exhaust outlet.
You must ensure that no exhaust fumes are drawn into the system.
The combustion air must not be drawn in from areas with a high
concentration of dirt and dust.
A ventilation opening measuring at least 100 cm
2
is required if the
heater is installed in an enclosed box.
The combustion air intake line may be extended with a special version
for heaters (available on request from Webasto). The maximum
dimensions of the combustion air intake line for this heater version are
as follows:
– Internal diameter: 60 mm
– Maximum line length: 3 m without the exhaust extension
– Maximum bend: 450°
The combustion air intake opening must be designed in such a way that
a sphere with a diameter of 16 mm cannot fit into it. The clear cross-
section must be maintained.
If the combustion air intake line cannot be installed so that it slopes
downwards, a water drain hole with a diameter of 4 mm is to be made at
its lowest point.
The size of the ventilation opening must be increased subject to
consultation with Webasto if the temperature in the box exceeds the
permitted ambient temperature of the heater (see Technical data).