Rinnai RH180 Operation And Installation Manual page 17

Ven ng Requirements
Vent Dampers
Vent dampers must be cer fied in accordance with ANSI Z21.68
Before installing any flue damper, consult the local gas authority and damper manufacturer for proper
installa on.
WARNING
Thermal Operated Vent Dampers: Should NOT be used with this appliance. This appliance has a thermal efficien-
cy greater than 80%. This higher efficiency will result in lower flue gas temperatures. Such temperatures may be
too low to ac vate a thermal operated vent damper. Use of a thermal operated flue damper on this product may
result in spillage of exhaust gases and ul mately carbon monoxide poisoning.
Vent Inspec on
The en re vent system (Combus on air ducts, louvers etc., and exhaust vent) must be checked periodically for
signs of obstruc on or damage. If damaged components are observed they must be repaired or replaced
immediately.
Vent Size
This water heater is equipped with a 4" vent adapter and must never be a ached to a vent smaller than 4".
Certain applica ons may require vent diameters greater than 4" Consult your local gas supplier or authority to
aid in the proper vent diameter selec on per the requirements of the vent tables in the current edi on of the
Na onal Fuel Gas Code ANSI Z223.1/NFPA 54.
Vent Connectors
Vent Connectors are rela vely short runs of vent connec ng the appliance to the chimney or ver cal vent run.
Following is a list of appropriate vent connector material for use between the water heater and the chimney:
Type B (B-Vent) Double wall, U.L. listed vent pipe
Type B (B-Vent) Single wall, U.L. listed vent pipe
Note the following when installing a vent connector from the appliance to the chimney or ver cal vent:
Length: A vent connector shall be as short as prac cal and the appliance located as close as prac cal to the
chimney or vent. The maximum horizontal length of the vent connector cannot exceed 75% of the
height of the chimney or vent. Unnecessary bends should be avoided as to not create excessive
resistance to flow of vent gases.
Prohibited loca ons: Vent Connectors cannot pass through any ceiling, floor, firewall, or fire par
Single wall vent connectors: A single wall vent
connector must not pass through any interior
walls, floors or ceilings. A single wall vent
connector must not be installed in a cs, crawl
spaces or any other confined space or inaccessible
loca on. Maintain a minimum of 6" from
combus bles when using single walled vent
connectors.
Double Walled, B-Vent: It is acceptable to pass
through walls or par
Vent.
Slope: Vent connectors must pitch ¼ inch per foot
(21mm per meter) upward.
ons with double walled, B-
RH180 Manual
CHIMNEY
OR
LISTED VENT
Vent Connector
MIN. ¼ inch rise
per foot
on.
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