Atmos Energy HE26 - Manual (Page 23)

5.4 General Flue Requirements
5.4.1 Flue terminal clearances
The flue terminal must be sited with minimum
clearance distances as shown in the diagram.
A terminal guard must be fitted if the terminal
is sited less than 2m above ground level, or
above a balcony, or accessible flat roof.
Where the flue terminates within 1m of a
plastic or painted gutter or within 500mm of
painted eaves, then protection should be
provided in the form of an aluminium shield at
least 1m in length, fitted to the underside of
the gutter or painted surface.
Please Note!
Due to the low flue gas temperature,
'pluming' will occur at the flue terminal.
Care should be taken to ensure that the
discharge plume will not cause annoyance
to the customer or neighbours. It is
generally recommended that flues should
discharge vertically at roof level. In this
position, pluming is not normally a
problem.
5.4.2 Flue system
The flue system must be installed in accordance with BS5440:1 and the
Building Regulations. Horizontal flue pipe runs must always be
installed with a minimum slope of 50 mm/metre towards the boiler.
This will prevent condensation from gathering in the flue pipe, and will also
reduce the chance of icicles forming over horizontal pipe ends in the
Winter.
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