Combustion Air Supply - Webasto Air Top 2000 ST Installation Instructions Manual

Marine Air Heaters
Air Top 2000 ST / Evo 40 / Evo 55
6

Combustion air supply

WARNING! Asphyxiation risk! The combustion air required for the
heater may only be drawn in from the outside or from spaces that are
not occupied by persons e.g. ventilated foredeck box or ventilated
*engine compartment (Diesel only).
*Explosion risk! Do not draw combustion air from engine compartment
of gasoline powered vessels.
6.1. Combustion air intake line
Combustion air intake line: must be arranged that it cannot be blocked

by objects
Keep combustion air intake line as short as possible

Mounting of combustion air intake line: with a hose clip at the intake

connection piece of the heater and with pipe clamps or cable ties on
fixed built-in components.
6.2. Combustion air intake from a well-ventilated area (locker,
stowage compartment or engine compartment)
No through-hull fitting required

The intake area must be at ambient pressure and sufficiently ventilated

to the outside!
Intake from engine compartment: the ventilation fan in the engine

compartment must not produce an overpressure or negative pressure
in the engine compartment.
Intake point: no intake of exhaust gases from heater or engine!

Fit a cap over the end of the hose to prevent water ingress (if no

through-hull fitting is used).
6.3. Combustion air intake directly from outside
Use a separate through-hull fitting if intake from a ventilated area is

not possible.
Arrange the end of the combustion air intake line as a gooseneck, as

illustrated. Prevent water from entering through the intake opening.
Do not position the through-hull fitting in the direction of travel (other-

wise backpressure and water ingress may occur in the intake pipe).
Fig. 27 Combustion air intake line not in direction of travel
Drill a drain hole at the lowest point as illustrated in Fig. 27.

Route hose free of kinks.

NOTE:
A combustion air intake line is required. A minimum
length is not specified. Max length 5m.
28
Combustion air