Miele PDR 910 G Plan D'installation page 10

en - Installation notes
*optional accessories
This tumble dryer is classified as a type B22 gas fuel-burning installation without flow
safeguarding equipment, and with a fan behind the heater.
Design of the exhaust air management system
The mixtures of exhaust gas and air that are emitted by gas-heated tumble dryers must
be discharged into the atmosphere individually via the roof.
In the case of combined lines, each gas-heated dryer must have a non-return flap.
Exceptions regarding the design of the exhaust air management system must be de-
signed in accordance with the applicable local building regulations. Seek approval from
the relevant building inspector.
- The connections between exhaust air ducts and the exhaust gas system must be kept as
short as possible.
- When connected to the vent ducting through the exhaust duct of a machine, particular
care must be taken to make sure the connection is secure and air-tight.
- Only use heat-resistant materials with a temperature resistance of at least 175°F (80°C).
- Condensation will form in the exhaust air management system. A condensate drain must
therefore be placed at the lowest point in the system.
Calculating the total ducting length
The friction of the vent ducting with its bends and various components provides resistance
to the flow of exhaust air. This friction resistance is expressed as a relative pipe length. The
relative pipe length indicates how much greater the resistance of a bend is, for example,
when compared to 1 meter of a straight plastic waste water pipe (Table I).
Adding together the relative pipe lengths for all of the components gives the total ducting
length. The total ducting length expresses the resistance of the entire exhaust air system.
As a larger duct diameter has a lower flow resistance, a longer duct requires a greater duct
diameter (Table II).
Procedure
1. Measure the length needed for the straight sections of vent ducting. Multiply this
value by the corresponding relative pipe length from Table I.
2. Calculate the number of bends and components needed. Use Table I to help you add
together their relative pipe lengths.
3. Add together all of the relative pipe lengths calculated above to calculate the total
ducting length.
4. Refer to Table II for the pipe diameter needed for the total ducting length.
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