Hot air system
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9
Hot air system
NOTE
The heater must not be integrated into the vehicle‘s front heating system.
Only recirculation air mode is possible, with the heating air intake from the
interior.
The recirculation mode ensures frost protection of the coolant hoses with
underfloor installation. It also contributes to a high total efficiency and
avoids fumes from the outside to be sucked inside.
The desired interior temperature can be adjusted at the Control Panel
(5 to 35 ºC). The heat is generated with a diesel-operated burner, and on
the RHA 101 / 102 also with an electric heater or with combined use of
both devices.
Power of the electric heater, depending on the type and setting:
RHA 101: low power = 600 W, high power = 1200 W
RHA 102: low power = 1000 W, high power = 2000 W.
The diesel powered heater automatically modulates the heating power be-
tween 1,500 W and 6,000 W depending on the output requirement (cal-
culated from difference between selected temperature and current interior
temperature).
To ensure that the heater functions satisfactorily, the flow resistance of the
connected hot air system has to be minimised. Maximum pressure drop be-
tween the inlet and outlet side of the hot air line: 3.0 hPa at maximum
speed of heating air ventilator.
(1 hPa corresponds to 1 mbar corresponds to 10 mm water column).
The points table for air guide parts in the Webasto air and water heaters
accessory catalogue can be used to design the hot air system.
The overall flow resistance of 3.0 hPa means that 190 points must not be
exceeded. Ensure that the air flow (air velocity) does not differ more than
factor two comparing the two hot air distribution channels.
If the resistance of the hot air distribution channels is too high, the temper-
ature sensors inside the heater will detect a high air temperature. This re-
sults in a higher speed of the heating air ventilator, causing then more
noise and power consumption.
The hot air hoses (intake and output) must be secured with clamps or
screws at their connection points.
NOTE
The installation must be checked for:
• No air short circuit between the vehicle‘s heating system and the heater
air inlet;
• No air short circuit between the heater‘s air inlet and the heater‘s air
outlet (see Fig. 21);
• No air leakage where openings have been made to route the hoses into
or outside the interior.
Fig. 21: Avoid short circuits
Содержание DUAL TOP RHA 100
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