The heater must not be installed in the passenger or
driver compartments of busses. Should the heater never-
theless be installed in such a compartment, the installa-
tion box must be sealed tight against the vehicle interior.
There must be sufficient ventilation of the installation box
from the exterior in order not to exceed a maximum tem-
perature of 40 °C in the installation box.
At filling stations and fuel depots the heater must be
switched off as there is a potential danger of explo-
sion.
Where flammable fumes or dust may build up (e.g.
in the vicinity of fuel, coal, wood, cereal depots, or
similar installations) the heater must be switched off
to prevent explosions.
Due to the danger of poisoning and suffocation the
heater must not be operated in enclosed areas such as
garages or workshops without exhaust venting, not even
if the start-up is activated by the timer or telestart device.
When removing the heater the gasket below must be re-
placed.
The heat exchanger of the air heater remains service-
able for a maximum of 10 years and must then be re-
placed with an original spare part by the manu-
facturer or by one of its authorized workshops.
The heater must then be provided with a label
marked with the sales date and with the words “Orig-
inal Spare”.
Should exhaust pipes be routed through rooms
accommodating persons, these pipes shall also be
renewed after 10 years.
Installations not legally authorized will void the air
heater’s “Official Marks of Conformity” and thus the
vehicle’s permit of operation. The same applies for
repairs performed by unskilled personnel and repairs
with no original spare parts.
1.5 Legal Provisions for Installation
For testing the heater in accordance with 19, 20, or 21
of the StVZO the following regulations are to be ob-
served in particular (§ 22 a StVZO):
Testing is performed upon presentation of the operating
and installation instructions of the manufacturer.
The year of the initial operation must be durably marked
on the heater identification plate by the installing person.
Heating Air System
Heating air intake openings must be arranged so that
under normal operating conditions exhaust fumes of the
vehicle engine or air heater are not likely to be expected.
Extracting combustion air from the vehicle interior is not
permissible.
Combustion Air Line
The combustion air required must be taken from the
exterior.
Within rooms accommodating persons, the combustion
air lines must not have more than four disconnects and a
splash-water protected exterior wall feedthrough. The
disconnects must be sealed in a way not to exceed a
leak rate of 200 l/h at an overpressure of 0.5 mbar.
The line including feedthrough, disconnects, material
and specific type must be described in the installation
instructions.
The line must require tools for installation and removal,
must be protected against damage, and must be shock-
proof.
Exhaust Line
Heaters must be designed to discharge the exhaust to
the exterior.
Exhaust pipes must be routed so that exhaust fumes are
unlikely to penetrate into the vehicle’s interior.
The function of any parts of the vehicle essential for its
operation must not be impaired. Condensate or water
penetrated must not be able to accumulate in the
exhaust line.
Drain holes are permissible; these must drain the fluid to
the exterior via lines sealed against the vehicle interior.
The exhaust line outlet is to be positioned to the top, to
the side, or in case of exhaust venting below the vehicle
floor, to the nearest possible location of the vehicle’s or
cockpit’s side or rear end. In compartments accommo-
dating persons, exhaust lines must not have more than
one disconnect and must have a splash-water protected
feedthrough in the exterior wall/floor. For water, that has
penetrated into the exhaust line, the connection of a
drain line with a metal-sealing joint is permissible. The
drain pipe must be routed sealed through the exterior
wall or the vehicle floor.The heat exchanger, the exhaust
line connected, as well as the possible drain pipe must
be sealed so that with an overpressure of double the
overpressure of the exhaust having the maximum per-
missible exhaust line length - at least however at an over-
pressure of 0.5 bar - a total leak rate of 30 l/h is not
exceeded.
The line including feedthrough, disconnects, material
and specific type must be described in the installation
instructions.
The line must require tools for installation and removal,
must be protected against damage, and must be shock-
proof.
102
1 Introduction
Air Top 2000 S
