Potterton Promax HE Store Installation & Servicing Instructions Manual page 20

16
14
12
10
8
6
4
2
0
0 1 2 3 4 5 6
Concentric 60/100 Flue (metres) Y
Example 1
Flue Lengths - Not Permissible
16
14
12
10
8
6
4
2
0
0
1
Example 3
Flue Lengths - OK
60Ø Exhaust
Y
Concentric 60/100 Flue
Promax Store
Additional Accessories
A - 93° Elbow
B - 45° Elbow (Pair)
C - 1 metre 60Ø Extension 5117380
20
16
14
12
10
8
6
4
2
0
7 8 9 0 1 2
Concentric 60/100 Flue (metres) Y
Example 2
Flue Lengths - OK
2 3 4 5 6
Concentric 60/100 Flue (metres) Y
X
45° Elbow
93° Elbow
Concentric Flue
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In the graph the solid line diagonal represents the
relationship between the concentric flue assembly
(and any extensions) and the 60Ø exhaust (and any
extensions or additional bends).
Example 1 - Not Permissible
If, for instance, a concentric length of 5 metres was
required and the 60Ø exhaust needed to be 10
metres the graph shows that this combination would
3 4 5 6 7 8 9
NOT be permissible as the intersection point would
be above the solid diagonal line.
Example 2 - Flue Lengths OK
Where both lengths have been determined they can
be applied to the graph to check that the installation
is permissible. For example, if it was known that 4
metres of concentric flue and 6 metres of 60Ø
exhaust were required, the values could be applied
to the graph as shown in Example 2. As the point of
intersection of the dotted lines is below the solid
diagonal line, the combination of lengths is shown
to be acceptable.
Example 3 - Flue Lengths OK
In the example shown, assume that the concentric
part of the flue needs to be 2 metres long. Find the
position of 2 on the horizontal axis of the graph
and then project upwards to the solid diagonal line.
This is represented by the vertical thick dotted line.
7 8 9
Where this dotted line intersects with the solid
diagonal line on the graph, project across to the
vertical axis. As can be seen this corresponds with
12 metres. Therefore, the total equivalent length of
the 60Ø exhaust can be up to 12 metres. Any bend
equivalencies must be accounted for i.e. 93° bends
are equal to 1 metre, each 45° bend to 0.5 metres.
Support
Bracket
1 metre Extension
1 metre supplied in kit
Determining Permissible Lengths
Flue Length - Worked Example
Potterton Promax Store
In diagram opposite an additional 93° bend and pair of
45° elbows have been included in the 60Ø exhaust.
Also 3 straight extension pieces have been used.
To calculate total length:-
Length of 60Ø supplied in kit =
3 x 1 metre Extensions =
1 x 93° Elbow =
2 x 45° Elbow =
Total 60Ø =
After consulting the table in Example 3 it can be
determined that the concentric flue could be up to
approximately 8 metres long.
© Baxi Heating UK Ltd 2012
1 metre
3 metres
1 metre
1 metre (0.5 metres
each)
6 metres