WarmFlow BoilerhouseB70HE User Manual page 63

8.1.7 Flue Length Calculation
Note:
1. All flues can utilise any combination of bends, straights, adapters and
terminals.
2. Ensure flue is arranged such that it falls continuously towards the boiler.
3. The Low Level, High Level and Vertical Balanced Flue Systems can use
any combination of flue extension pieces up to the maximum equivalent
length depending upon boiler output as illustrated in the above table.
Example Calculation:
Boiler Output: 20kW
Length of Flue (distance from boiler to terminal): 8.0m
Example 1: No bends fitted.
Length of vertical flue
No bends
Equivalent length
Equivalent length within the maximum allowable.
INSTALLATION ACCEPTABLE.
Example 2: 2 x 45° bends fitted.
Length of vertical flue
2 x 45° bends
Equivalent length
Equivalent length now exceeds the maximum allowable.
INSTALLATION NOT ACCEPTABLE.
8.0m
0.0m
8.0m
8.0m
1.0m
9.0m
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