Combustion Air Supply - Webasto Thermo Pro 90 Installation Instructions Manual

Thermo Pro 90
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Combustion air supply

The air inlet (ø 30 mm) must be so positioned or guarded that blocking by rub-
bish or luggage is unlikely.
(Requirement from ECE-R 122, point 5.3.5.2.).
Under no circumstances may the combustion air be taken from areas occupied
by persons.
The fuel intake opening must be arranged in such a way that it cannot become
clogged with dirt. It must not face in the direction of travel.
The take-off point for the combustion air must be positioned in a splash-proof,
cool position above the wading line of the vehicle.
A combustion air intake line is required.
A combustion air line with a minimum length of 0.5 m and a minimum internal
diameter of 30 mm should always be used.
The maximum permissible length of the combustion air line is 5.0 m.
The combustion air line may have a number of bends, but the sum of the bend
angles must not exceed 360°.
The smallest permitted bending radius is 45 mm.
The combustion air intake may not be routed above the exhaust outlet.
If it is not possible to install the combustion air intake line with a
continuous incline from the outlet opening to the heater, a con-
densation drain hole with a diameter of 4 mm must be installed
at the lowermost point.
When installing the heater in the vicinity of the vehicle fuel tank in a common
installation space, the combustion air intake must come from the open air
and the exhaust gas must be expelled to the open air. Through holes must be
made splash-proof.
If the heater is in an enclosed casing, a ventilation opening is required. This
opening should be at least twice the diameter of the combustion air intake
line. If the temperature in the casing exceeds the permissible ambient tem-
perature for the heater (see Chapter 14 Technical data, on page 56), the
ventilation opening must be enlarged accordingly.
Combustion air
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