18 RIVA FP MANUAL
9. Ventilation Cont.
The Riva is a mechanical draft, side wall vented boiler. There are two
fl
ue options available -
separate and coaxial. The coaxial option has one con
fi
guration shown on the next page. The
separate option has two possible con
fi
gurations shown on the following pages.
9.1 Restrictor Sizing:
Each exhaust option is shipped standard with 3 feet of exhaust pipe, 3 feet of intake air pipe.
There is also a restrictor kit in which there are some restrictors that must be placed in exhaust
breech of fan on the top of the boiler (Fig. 9.1) according to the
fl
ue con
fi
guration used.
If additional
fl
ue piping is need for a particular application, it can be ordered separately in 3 feet
increments. Depending on the
fi
nal
fl
ue pipe length, an alternative restrictor may be required.
Refer to the tables 9.1 for proper restrictor ring sizing.
Figure 9.1
Coaxial 2.5/4.0
Restrictor Size
From 1.65 to 3.30 (ft)
41
From 3.30 to 8.86 (ft)
44
Separate 3.25/3.25
Restrictor Size
For 1.65 (in) and 1.65 (out)
38
From 3.30 to 39.40 (in+out)
41
Table 9.1
9.2 Fitting the fl ue system:
In general, it has to be taken in consideration that the horizontal sections of the
fl
ue pipe must
have an horizontal sloping not less than 1.5 degree (0.3 in per ft) towards the boiler.
In the standard horizontal
fl
ue kit the
fl
ue pipe is angled within the air duct therefore the air duct
must be horizontally installed.
If one or more exstensions have to be used they must be adequately supported so that there
is no sag in the
fl
ue pipe and a minimum fall of 1.5 degree (0.3 in per ft) over the whole lenght
towards the boiler is ensured.
