Flue Lengths; General Information; Determining The Flue Length; Installation Analysis - Bosch Condens 5000 W Information

5

Flue lengths

5.1

General information

The condensing boilers are fitted with a fan that transports the flue gases
into the flue. Flow losses inside the flue decelerate the flue gases.
Consequently, flues must not exceed a specific length to ensure the flue
gases are securely propelled to the outside. This length is the maximum
equivalent pipe length L
equiv,max
its routing. Flow losses are greater in ebows than in straight pipes. An
equivalent pipe length is therefore assigned to elbows that is greater
than their physical length. The sum of horizontal and vertical pipe
lengths as well as the equivalent pipe lengths for the elbows used,
results in the equivalent flue length L
shorter than the maximum equivalent pipe length L
in some flue gas systems the length of horizontal flue L
a certain value L .
w,max
5.2

Determining the flue length

5.2.1

Installation analysis

▶ Determine the following from the given installation situation:
– Route of the flue
– Routing the flue gas to AS/NZ 5601
– Condensing boiler
– length of horizontal flue, L
– length of vertical flue, L
s
– Number of additional 90 ° deviations in the flue
– Number of 15 °, 30 ° and 45 ° elbowsin the flue
Condens 5000 W – 6720644146 (2019/03)
. It is subject to the boiler, the flue and
. This total length must be
equiv
. In addition,
equiv,max
must not exceed
w
w
5.2.2

Determining the parameters

The flue may be routed as follows:
• Vertical flue ( Tab. 6 on page 12 and Tab. 7 on page 13)
• Horizontal flue ( Tab. 6 on page 12 and Tab. 7 on page 13)
▶ Determine the following from the respective table, subject to the
method of routing the flue to
AS/NZ 5601, condensing boiler and flue diameter:
– Maximum equivalent pipe length L
– Equivalent pipe length of elbows
– Poss. maximum horizontal pipe length L
5.2.3 Calculation of the equivalent pipe length L
The equivalent pipe length L
equiv
horizontal and vertical flue lengths (L
elbows. The required 90 ° elbows are included in the maximum lengths.
Take every additional elbow with its equivalent length into
consideration.
The equivalent total pipe length must be shorter than the maximum
 L
equivalent pipe length: L
equiv
For an example of calculating the flue length, see page 14.
Flue lengths
equiv,max
w,max
equiv
is calculated from the sum of the
, L ) and the equivalent lengths of
w s
equiv,max
11