External Temperature Sensor - Webasto Air Top 2000 ST Installation Manual

Heating Air Circuit
5.3 Heating Air Intake Options
Option 1, Recirculation Mode:
The return air for heating is drawn in from the cabin (and any side-rooms) either via flexible ducting or return
openings. Use a Webasto fixed open grille to terminate the flexible duct. If the heater is mounted in a locker,
use the grille supplied in the kit to ventilate the locker.
Locate the air intake grille close to the heater intake, so that outside air is drawn in, in preference to the
locker air. It is not necessary to connect the grille to the heater with flexible ducting, unless there is a risk of
contaminated air reaching the heater.
If the heater is fitted in the engine room, use flexible ducting to draw in fresh cabin air, thus, avoiding engine
room air and associated fumes from being drawn into the heating air system.
Option 2, Fresh Air Intake Mode:
The air for heating is drawn into the heater from an external source either via flexible ducting or a grille
located on an external locker wall or wall opening. It is important that the rooms being heated are
adequately ventilated, otherwise air flow through the heater will be reduced, in which case the heater's
overheat protection is likely to respond.
WARNING!
Asphyxiation risk! The fresh air intake must be located where exhaust fumes from the heater or the
engine cannot be drawn in to the heater intake and heating system.
To control the room temperature in the case of fresh air intake, an optional external temperature sensor
must be installed in a location with average room temperature and be connected to the control unit.
ATTENTION!
IT IS IMPORTANT THAT A SUPPLY OF CLEAN, UNOBSTRUCTED AIR REACHES THE HEATER THROUGHOUT ITS
OPERATION.
5.4 Hot Air Outlets
Hot air outlets should be located low in the rooms being heated. Be aware that the heated air discharged
can reach temperatures upwards to 90 °C (200 °F). Outlets should be located where contact with
passengers is unlikely. The hot air discharge should not be directed towards heat sensitive components or
surfaces in the immediate vicinity of the outlet.
Avoid long runs of ducting; they are inefficient and could lead to over heating. A heater is more efficient
when venting the hot air into free cabin space rather than being confined to a "rabbit warren" of ducting.
It is not always necessary to place outlets at every point where heat is desired. The pressure of the fan,
(particularly with minimal ducting), is effective at reaching most parts of the vessel. Keep the duct runs as
straight as possible and avoid running ducts where they could become crushed or broken.
The following diagrams illustrate typical ducting systems created with "Y" or "T" branches and outlets. Use
the clips provided to secure duct joints.
Webasto Thermo & Comfort N.A., Inc.
Air Top 2000 ST - Air Top Evo 40/55
20 www.techwebasto.com