Navien NR-180 Installation Manual page 27

Navien Gas Water Heater Installation
█ Venting:
 To fit the unit for non-direct vent, insert the termination end cap (provided with the
Water Heater) into the intake air duct. Do not glue to allow for easy removal and
cleaning of the cap.
Combustion Air Supply Requirement for Non-Direct Vent
 When a Navien Water Heater is installed without a dedicated intake air pipe (non-
Direct Vent) communicating directly with the outdoors, combustion air must be
supplied to the space. The opening sizes below are Navien's minimum requirements.
Follow the latest version of the National Fuel Gas Code (ANSI Z223.1 / NFPA 54) or
CAN/CGA B-149.1.
Model
Maximum Input (BTUH)
Outdoor make up air is
provided, a minimum free
area of 1 in2
Indoor make up air is
provided, a minimum free
area of 1 in2
NR, NP-180 (A) NR, NP -210 (A)
150,000 180,000
2
5.3 in 6.1 in
3" (W) x 2" (H) 2.5" (W) x 2.5" (H)
or 3" round or 3" round
2
150 in 180 in
12¼" (W) x 12¼" (H) 13¼" (W) x 13¼" (H)
:
NR, NP -240 (A)
199,000
2 2
7 in
2¾" (W) x 2¾" (H)
or 3" round
2 2
199 in
14¼" (W) x 14¼" (H)
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