Guidelines For A Common Vent System - Navien NPE-180A2 Installation Manual

5.1.1 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.
the Navien Common Vent Collar Kit must be
-
installed in the exhaust duct of each water
heater unit.
use direct vent (with separate intake and
-
exhaust lines) or indirect vent (combustion
air drawn from room) systems.
do not mix different model units within one
-
common vent system. Model types of all the
water heater units in a common vent system
must be identical.
This section covers the installation of a common
●
vent system for NPE water heaters 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
70).
A maximum of 12 NPE water heaters may be
●
connected to one common vent system. In a
cascade system that has more than 12 water
heaters, use 2 common vent systems, or consult
Navien.
Use the proper PVC cements and adhesives
●
that are recommended for use by the pipe
manufacturer.
Position the water heater 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 water heater unit.
The common vent system covered in this manual
●
is approved for direct and non-direct vent
applications.
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 the indicated intervals or as required by local
codes.
Install a Common Vent Collar Kit for each water
●
heater unit. Use only the damper specified in this
manual.
To avoid moisture and frost build-up and to
●
maintain clearances to openings on adjacent
homes, 45° elbows, 90° elbows, or tees may be
attached to the end of the termination vent pipe
to direct the exhaust plumes away from buildings,
as long as the total allowable vent lengths,
maximum number of elbows, and distances to air
intake restrictions are observed.
If the water heater units will be installed in areas
●
where snow is known to accumulate, protect
the vent termination from blockage. Ensure that
the vent termination is at least 12 in (305 mm)
above ground, 12 in (305 mm) above the highest
anticipated snow level, or as required by local
codes, whichever is greater. Snow removal may
be necessary to maintain clearance.
The vent for this appliance shall not terminate
●
over public walkways; or near soffit vents or crawl
space vents or where condensate or vapor could
create a nuisance or hazard or cause property
damage; or where condensate or vapor could
cause damage or could be detrimental to the
operation of regulators, relief valves, or other
equipment.
Installing a Common Vent System 65