Navien NFC-250/175H, Installation Manual

Page: 71 / 151

71 Venting for Combustion Air
Ref Description
Canadian Non-Direct
Vent Installations
1
US Non-Direct Vent
Installations
2
A
Clearance above grade, veranda, porch, deck,
or balcony
12 in (30 cm) 12 in (30 cm)
B
Clearance to window or door that may be
opened
36 in (91 cm)
48 in (120 cm) below or
to side of opening; 12 in
(30 cm) above opening
C Clearance to permanently closed window * *
D
Vertical clearance to ventilated soffit located
above the terminal within a horizontal distance
of 2 feet (61 cm) from the center line of the
terminal
* *
E Clearance to unventilated soffit * *
F Clearance to outside corner * *
G Clearance to inside corner * *
H
Clearance to each side of center line extended
above meter/regulator assembly
36 in (91 cm) within
a height 15 ft
(4.57 m) above the meter/
regulator assembly
*
I Clearance to service regulator vent outlet 36 in (91 cm) *
J
Clearance to non-mechanical air supply inlet
to building or the combustion air inlet to any
other appliance
36 in (91 cm)
48 in (120 cm) below or
to side of opening; 12 in
(30 cm) above opening