Navien NFB-175H, Руководство по установке, Страница: 77 / 135

77 Installing a Common Vent System
9.1.1 Guidelines for a Common Vent
System
CAUTION
●
To ensure the correct operation of the
common vent system,
-
a cascade communication cable MUST be
installed between all units in the common
vent system by the installer.
-
backflow vent dampers must be installed in
the exhaust duct of each boiler unit.
-
use direct vent (with separate intake and
exhaust vent) or
indirect vent
(combustion
air drawn from room) systems.
●
Common vent installations for use with
natural gas and propane are only approved
for up to 4,500 ft.
●
This manual covers the installation of a
common vent system for
NFB-H boilers
only
.
To ensure the safe and correct installation of
the common vent system, carefully follow the
instructions and guidelines.
●
Check to see if all contents are included in the
package (refer to the “Included Items” on page
82).
●
A maximum of 8 NFB-H boilers may be connected
to one common vent system. In a cascade system
that has more than 8 boilers, use 2 common vent
systems, or consult Navien.
●
Use only the PVC cements specified in this
manual when connecting pipes, joints, or elbows.
●
Position the boiler units as close as possible to the
vent termination.
●
Install a new vent system with this appliance. If an
existing vent system is reused, thoroughly inspect
it for punctures, cracks, or blockages prior to
connecting it to the boiler unit.
●
Horizontal vent pipe runs must be supported
every 4 feet (1.2 m) (minimum). All vertical vent
pipe runs must be supported every 6 feet (1.8 m)
(minimum). Support the vent pipe with hangers
at regular intervals or as required by local codes.
●
Install a Navien Backflow Damper Kit for each
boiler unit. Use only the damper specified in this
manual.
9.1 About the Common Vent
System
The Navien Common Vent System* provides an easy
way to install the vent system for up to 8 Navien
NFB-H boiler units. By sharing the main intake and
exhaust vent pipes, effective system venting is
available with less venting materials and minimal
number of penetrations on the walls or roofing.
* Independently tested and approved by CSA
Read all safety messages and carefully follow the
guidelines in this manual when installing a common
vent system for the NFB-H boiler units.
WARNING
Improper venting of the boiler units can result
in excessive levels of carbon monoxide, which
can lead to severe personal injury or death.
The
boiler units must be vented in accordance
with the “Venting of Equipment“ section of
the latest edition of the ANSI Z223.1/NFPA
54 Natural Fuel Gas Code in the USA, as
well as all applicable local building codes
and regulations. Follow all instructions and
guidelines when venting the boiler units.
Venting should be performed only by a licensed
professional.
9. Installing a Common Vent System