36
Rinnai Tankless Water Heater Installation and Operation Manual
4.5.5 Direct Vent (Concentric and Twin Pipe):
Termination Clearances
The information below applies to Concentric and Twin Pipe.
Canadian Installations
1
(CSA B149.1)
U.S. Installations
2
(ANSI Z223.1/NFPA 54)
Ref
Description
Direct Vent (Indoor Unit)
Direct Vent (Indoor Unit)
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)
12 in. (30 cm)
C
Clearance to permanently closed window
*
*
D
Vertical clearance to ventilated soffit, located above the terminal within
a horizontal distance of 2 ft (61 cm) from the center line of the terminal
*
*
E
Clearance to unventilated soffit
*
*
F
Clearance to outside corner
*
*
G
Clearance to inside corner
*
12 in.
H
Clearance to each side of center line extended above meter/regulator
assembly
3 ft. (91 cm) within a height
of 15 ft. (4.6 m)
*
I
Clearance to service regulator vent outlet
3 ft. 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)
12 in. (30 cm)
K
Clearance to a mechanical air supply inlet
6 ft (1.83 m)
3 ft (91 cm) above if within 10 ft (3
m) horizontally
L
Clearance above paved sidewalk or paved driveway located on public
property
7 ft (2.13 m) [1]
Vents for Category II and IV
appliances cannot be located above
public walkways or other areas
where condensate or vapor can
cause a nuisance or hazard.
M
Clearance under veranda, porch, deck, or balcony
12 in. (30 cm) [2]
*
Clearance to opposite wall is 24 in. (60 cm).
[1] A vent shall not terminate directly above a sidewalk or paved driveway that
is located between two single family dwellings and serves both dwellings.
[2] Permitted only if veranda, porch, deck, or balcony is fully open on a
minimum of two sides beneath the floor..
*Clearances are in accordance with local installation codes and
the requirements of the gas supplier.
(Dégagement conforme aux
codes d’installation locaux et aux exigences du foumisseur de
gaz.)
AIR SUPPLY INLET
VENT TERMINAL
AREA WHERE TERMINAL
IS NOT PERMITTTED
X
V
SNOW
TERMINATION
Clearance in
Ref.
A also
applies to
anticipated
snow line
Regulator vent outlet
AIR SUPPLY INLET
VENT TERMINAL
AREA WHERE TERMINAL
IS NOT PERMITTTED
X
V
SNOW
TERMINATION
Clearance in
Ref.
A also
applies to
anticipated
snow line
Figure 21: Direct Vent Termination Clearances
Table 13
Notes:
1
In accordance with the current CSA B149.1, Natural Gas and Propane Installation Code.
2
In accordance with the current ANSI Z223.1/NFPA 54, National Fuel Gas Code.
I
If locally adopted installation codes specify clearances different than those illustrated, then the most stringent clearance shall prevail.
