Venting The Water Heater - Navien NPE-180A Installation Manual

3.6 Venting the Water Heater

WARNING
Improper venting of the water heater can result in excessive
levels of carbon monoxide, which can lead to severe personal
injury or death. This water heater 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 and/or the "Venting systems and air
supply for water heaters" section of the latest version of
the CAN/CGA B149.1 Natural Gas and Propane Installation
Code in Canada, as well as all applicable local building
codes and regulations. Follow all instructions and guidelines
when venting the water heater. Venting should be performed
only by a licensed professional.
The water heater must be properly vented to ensure a constant
supply of clean intake air and to ensure that exhaust air is properly
removed from living areas. When venting the water heater, follow
these guidelines:
Do not install the water heater in areas with contaminated air
(containing a high level of dust, sawdust, sand, flour, aerosols,
or any other such airborne contaminants), as contaminants
can cause operational problems. The warranty does not cover
damage caused by contaminants in the installation area. If you
must install the water heater in an area with contaminated air,
use direct venting to supply air from outside the building. We
recommend regular filter cleaning and maintenance in these
areas.
For best results, keep the venting system as short and straight as
possible.
Locate the water heater as close as possible to the vent
termination.
Do not connect the water heater vent to a vent for any other gas
water heater or vent stack.
For horizontal runs, slope the horizontal section upward toward
the vent termination at a rate of 1/4" per foot (2% slope).
Create an airtight seal at each joint in the exhaust and intake air
pipes from the water heater collar to the vent termination.
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.
Do not store hazardous or flammable substances near the vent
termination.
If this water heater 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" (305mm) above
ground, or as required by local codes.
Support the vent pipe with hangers at regular intervals or as
required by local codes.
Exhaust and intake air pipes must be supported at least every 4
feet (1.2m).
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.
3.6.1 Selecting a Vent Type
All water heaters are prepared at the factory to be direct vent
(sealed combustion) water heaters that draw all of their required
combustion air directly from outside the building. Navien
recommends direct air vent installations whenever possible to
avoid back drafting cold air through the water heater. If you cannot
use a direct vent, ensure that an ample supply of make-up air is
available in the installation location.
Navien also recommends installing a new vent system with this
appliance. If reusing an existing vent system, thoroughly inspect
it for punctures, cracks, or blockages prior to connecting it to the
water heater.
Direct Venting
The water heater uses 2" or 3" diameter exhaust and 2" or 3"
diameter intake air ducts. To ensure the draw of air directly from
and exhaust of air directly to the outside of the building, create an
airtight seal from the water heater collar to the vent termination.
Intake materials can be made of ABS, PVC, CPVC, PP, galvanized
steel, corrugated aluminum or any other such materials. If you
use a corrugated material, ensure that there is not inadvertent
crimping of, or damage to, the intake air pipe.
When using direct venting, maintain the following venting
clearances, as required by ANSI Z21.10.3 and the National Fuel
Gas Code, ANSI Z223.1/NFPA 54, and CAN/CGA B149.1 Natural
Gas and Propane Installation Code:
Installing the Water Heater 27