Product specifications

Figure 4: Examples of flue installation options
The equivalent length of the required flue system's
configuration can be calculated from the resistance
factors given for the individual flue components in
Table 3. In the worked example (Fig 7), the
maximum permitted combined length for a 80mm
dia. twin flue is 64metres at a pressure of 100 Pa.
Account has already been taken of the resistance of
the balanced flue terminal. This can therefore be
ignored in the calculation.
Flue Component Equivalent
Distance metres
Pipe 80
single
80/125
conc
Straight length of 1m 1.0m 1.0m
Bend 90 deg 3.0m 3.0m
Bend 45 deg 1.5m 1.5m
Table 3. Flue resistance factors
Figure 5: Twin pipe terminal plate
The twin pipe horizontal wall terminal comprises a
terminal plate, two 500mm lengths of 80mm dia.
plastic pipe and internal plate. In addition, two 90º
bends are required.
Figure 7: Worked flue length example.
ATMOS MULTI Mk 2 version 2008
Page 14