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Notes on installation
Exhaust air duct
All standard products can be used for the exhaust air duct:
– flexible pipes
– galvanised metal ducts or pipes
– connectors, adapters, and diverters for flat duct systems and pipe systems
– wall boxes for evaporation into the open air or into a ventilation shaft
– adapters on rectangular ducts
– rectangular ducts or plastic pipes
– backpressure flap
The material must be heat resistant up to 80 °C and moisture resistant.
Pressure losses
The type and length of the exhaust air duct, particularly elbows or bends with small radii,
can impede the air flow.
Keep diameter reductions and pressure losses (resistance)
to a minimum.
The following must be avoided:
– long exhaust air ducts
– exhaust air ducts with small diameters
– exhaust air ducts with many bends and elbows.
Pressure losses through friction
Duct or pipe friction resistance, i.e. friction on the inside of the exhaust air duct, affects
the air flow as follows:
– the smoother the internal wall
– the larger the diameter of the internal wall
– the shorter the pipe
the lower the friction resistance.
Pressure losses due to fixtures
The exhaust air encounters further resistance through fixtures built into the pipe, e.g.
diverters (bends, elbows, angles), wall boxes with grids or backpressure flaps.
Installation for pipe connection - inside diameter = 100 mm
In order to ensure the minimum required air flow, a certain pressure loss (resistance) must
not be exceeded.
The permissible total pressure loss in an exhaust air duct must not exceed a certain value.
This is calculated as the sum of all individual pressure loss values for the straight pieces
and fixtures in the exhaust air duct.
The value for the maximum permissible total pressure loss for an exhaust air duct is 50*.
Installation for pipe connection - inside diameter = 100 mm
If the pipe connection has an inside diameter > 100 mm and a total pressure loss greater
than 50*, increase the inside diameter of the pipe connection
* To determine the total pressure loss see table
page 6.
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Installation options
– Route the exhaust air duct in such a way that the dryer cannot draw the moist, warm
exhaust air back in again.
– The outlet for the exhaust air must be designed or positioned in such a way as
to prevent any additional backpressure (e.g. from a direct ingress of wind) on
the escaping exhaust air, e.g. by using a 90° bend, facing down
– The outlet for the exhaust air duct must be no more than 2.5 m higher than the exhaust
air opening on the appliance.
Installation options for the exhaust air duct:
1.
Through a wall box into the open air
Example: pipe connection - inside diameter = 100 mm,
smooth
A = straight piece (1.0 m)
B = curved pipe (R = 200 mm)
C = straight piece (1.5 m)
D = pipe elbow
E = telescopic wall box with grid
Total pressure loss
Directly into the open air
2.
Route the exhaust air directly into the open air via an exhaust
air pipe through an open window.
Example:
Pipe connection - inside diameater = 100 mm, flexible pipe,
corrugated
A = curved pipe (R = 300 mm)
B = straight piece (1.5 m)
C = curved pipe (R = 100 mm)
D = straight piece (0.5 m)
Total pressure loss
3.
Through a wall box into chimneys or ventilation shafts
– It is not permitted to connect the exhaust air duct to chimneys which are connected
to gas or coal-fired ovens/cookers or gas-fired heating systems.
– If the appliance is being connected to a moisture-insulated ventilation shaft the
responsible chimney sweep must be informed and the approval of the local building
department (building supervision office) or the owner of the building must be obtained.
– If other appliances are operated in the room where the appliance is installed or
in adjoining rooms, e.g. gas-fired heating systems, gas-fired boilers, coal-fired ovens
connected to a chimney, or open fireplaces, a vacuum may be created, leading
to waste gases being sucked back
– In every case, have safe operation confirmed by the responsible chimney sweep, boiler
engineer, ventilation specialist, etc.
page 7.
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risk of poisoning .
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