Baxi Nuvola 3 Comfort Operating And Installation Instructions page 18

For detailed installation instructions, consult the technical data provided with the accessories.
... separate flue and air ducts
This type of installation makes it possible to discharge exhaust fumes both outside the building and into single flue ducts. Comburent
air can be drawn in at a different location from that of the flue terminal. The splitting kit comprises a flue duct adaptor (100/80) and an
air duct adaptor. For the air duct adaptor, fit the screws and seals previously removed from the cap.
The diaphragm in the boiler must be removed in the event of installation with these types of ducts.
Figure 9
• A 90° bend reduces total duct length by 0.5 metres.
• A 45° bend reduces total duct length by 0.25 metres.
Adjusting the air regulator for separate flues
This regulator must be adjusted to optimise combustion efficiency and parameters. After turning the air intake connecter, which can be
mounted both to the right and the left of the exhaust flue duct, suitably adjust the excess air according to the total length of the combu-
stion exhaust and inlet flue ducts.
Turn this regulator clockwise to decrease the excess of comburent air and
vice versa to increase it.
To fine tune, use a combustion product analyser to measure the amount
of CO2 in the fumes at maximum heat capacity, and, if a lower value is
measured, gradually adjust the air regulator until the amount of CO2 in-
dicated in the following table is measured. To mount this device correctly,
consult the relative instructions.
NUVOLA 140 Fi
INSTRUCTIONS FOR FITTERS
NOTE:
when calculating the maximum available
length.
The 90° bend allows the boiler to be con-
nected to a flue-air duct in any direction as
it can be rotated by 360°. It can also be used
as a supplementary bend combined with a
duct or a 45° bend.
Model 240-280
Index
Opening
18
The first 90° bend is not included
Model 320
Intake coupling
Figure 10
C607215 - GB