12
Prior to installation
Exhaust-air mode
The exhaust air is discharged upwards
through a ventilation shaft or directly
through the outside wall into the open.
D
Exhaust air should neither be directed
into a smoke or exhaust flue that is
currently used for other purposes, nor into
a shaft that is used for ventilating rooms in
which stoves or fireplaces are also located.
Exhaust air may be discharged in
accordance with official and statutory
regulations only (e.g. national building
regulations).
Local authority regulations must be
observed when discharging air into smoke
or exhaust flues that are not otherwise in
use.
D
When the extractor hood is operated
in exhaust-air mode simultaneously with
a different burner which also makes use
of the same chimney (such as gas, oil or
coal-fired heaters, continuous-flow heaters,
hot-water boilers) care must be taken to
ensure that there is an adequate supply
of fresh air which will be needed by the
burner for combustion.
Safe operation is possible provided that the
underpressure in the room where the
burner is installed does not exceed 4 Pa
(0.04 mbar).
This can be achieved if combustion air can
flow through non-lockable openings, e.g. in
doors, windows and via the air-
intake/exhaust-air wall box or by other
technical measures, such as reciprocal
interlocking, etc.
If the air intake is inadequate, there is a
risk of poisoning from combustion gases
which are drawn back into the room.
An air-intake/exhaust-air wall box by itself
is no guarantee that the limiting value will
not be exceeded.
Note: When assessing the overall
requirement, the combined ventilation
system for the entire household must be
taken into consideration. This rule does not
apply to the use of cooking appliances,
such as hobs and ovens.
If the exhaust air is going to be
discharged into the open, a telescopic
wall box should be fitted into the outside
wall.
For optimum extractor hood efficiency:
❑
Short, smooth air exhaust pipe.
❑
As few bends in the pipe as possible.
❑
Diameter of pipe to be as large as
possible and no tight bends in pipe.
If long, rough exhaust-air pipes,
many pipe bends or smaller pipe
diameters are used, the air extraction
rate will no longer be at an optimum
level and there will be an increase in
noise.
ṇ The manufacturer of the
extractor hoods accepts no liability
for complaints which can be
attributed to the design and layout of
the pipework.
