Table of Contents
Advertisement
Installation and connection
en
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
Note:
permissible total pressure loss for an
exhaust air duct is 50
inside diameter > 100 mm
■
If the pipe connection has an inside
diameter > 100 mm and total
pressure loss greater than 50*,
increase the inside diameter of the
pipe connection.
*
To determine the total pressure loss
see table ~ "Individual pressure
loss values" on page 17
16
*
.
Advertisement
Table of Contents
