QHT Riva Installation, Operation And Service Instructions - page 20
RIVA HEAT ONLY MANUAL - REV B
20
The Riva is a mechanical draft, side wall vented boiler. There are two flue options
available - separate and coaxial. The coaxial option has one configuration shown on the
next page. The separate option has two possible configurations 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 flue
configuration used.
If additional flue piping is need for a particular application, it can be ordered separately in
3 feet increments. Depending on the final flue 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 flue system:
In general, it has to be taken in consideration that the horizontal sections of the flue
pipe must have an horizontal sloping not less than 1.5 degree (0.3 in per ft) away
from the boiler.
In the standard horizontal flue kit the flue 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 flue pipe and a minimum fall of 1.5 degree (0.3 in per ft) over the
whole lenght towards the boiler is ensured.
9. Venting Cont.