5894307-UIM-B-0920
18
Johnson Controls Ducted Systems
VENT CLEARANCES
† A vent must not terminate directly above a sidewalk or paved driveway that is located between two single family dwellings and serves both dwellings.
†† 12 in. (30.5 cm) up from the bottom edge of the structure for two-pipe (direct vent) applications per ANSI Z223.1 / NFPA 54, National Gas Code.
‡ Permitted only if veranda, porch, deck, or balcony is fully open on a minimum of two sides beneath the floor and the distance between the top of the vent termination
and the underside of the veranda, porch, or deck is greater than 12 in. (30.5 cm) as specified in CSA B149.1-00.
Notes:
A vent must not terminate less than 12 in. (30.5 cm) above a grade level.
Any fresh air or make up inlet for dryer or furnace area is considered to be forced air inlet.
Avoid areas where condensate drippage may cause problems such as above planters, patios, or adjacent to windows where steam can cause fogging.
Fit a terminus of a vent with a cap in accordance with the vent manufacturer’s installation instructions or the installation instructions for a special venting system.
Responsibility for the provision of proper adequate venting and air supply for application rests with the installer.
Vent must extend high enough above building or a neighboring obstruction so wind from any direction does not create a positive pressure in the vicinity of the vent.
Figure 19:
Home Layout
L
E
D
B
V
V
V
X
V
B
V
J
X
B
B
B
V
V
F
V
C
B
X
V
I
V
G
H
A
M
K
OPERABLE
FIXED
CLOSED
VENT TERMINAL
AIR SUPPLY
AREA WHERE TERMINAL IS NOT PERMITTED
FIXED
CLOSED
Direct Vent Terminal Clearances
Canadian Installations
1,3
US Installation
2,3
A. Clearance above grade, veranda, porch, deck, or
balcony
12 in. (30.5 cm)
12 in. (30.5 cm)
B. Clearance to window or door that can be opened
12 in. (30.5 cm) for models
100,000 BTUH (30 kW)
36 in. (91.4 cm) for models >100,000 BTUH (30 kW)
Two-pipe (direct vent) applications: 12 in. (30.5 cm)††
Single-pipe applications: 4 ft (1.2 m)
C. Clearance to permanently closed window
12 in. (30.5 cm)
12 in. (30.5 cm)
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
12 in. (30.5 cm) or in accordance with local installation
codes and the requirements of the gas supplier
12 in. (30.5 cm) or in accordance with local installation
codes and the requirements of the gas supplier
E. Clearance to unventilated soffit
12 in. (30.5 cm) or in accordance with local installation
codes and the requirements of the gas supplier
12 in. (30.5 cm) or in accordance with local installation
codes and the requirements of the gas supplier
F. Clearance to outside corner
12 in. (30.5 cm) or in accordance with local installation
codes and the requirements of the gas supplier
12 in. (30.5 cm) or in accordance with local installation
codes and the requirements of the gas supplier
G. Clearance to inside corner
3 ft (91.4 cm)
3 ft (91.4 cm)
H. Clearance to each side of center line
extended above meter/regulator assembly
Above a meter/regulator assembly within 3 ft (91.4 cm)
horizontally of the vertical center-line of the regulator
vent outlet to a maximum vertical distance of 15 ft
(4.5 m) above the meter/regulator assembly
Above a meter/regulator assembly within 3 ft (91 cm)
horizontally of the vertical center-line of the regulator
vent outlet to a maximum vertical distance of 15 ft
(4.5 m) above the meter/regulator assembly
I. Clearance to service regulator vent outlet
3 ft (91.4 cm)
3 ft (91.4 cm) or in accordance with local installation
codes and the requirements of the gas supplier
J. Clearance to non-mechanical air supply inlet to
building or the combustion air inlet to any other
appliance
12 in. (30.5 cm) for models
100,000 BTUH (30 kW)
36 in. (91 cm) for models >100,000 BTUH (30 kW)
Two-pipe (direct vent) applications: 12 in. (30.5 cm)
Single-pipe applications: 4 ft (1.2 m)
K. Clearance to a mechanical supply inlet
6 ft (1.83 m)
3 ft (91.4 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)†
7 ft (2.13 m) or in accordance with local installation
codes and the requirements of the gas supplier
M. Clearance under veranda, porch, deck, or balcony
12 in. (30.5 cm)‡
12 in. (30.5 cm) or in accordance with local installation
codes and the requirements of the gas supplier
1. In accordance with the current CSA B149.1-00, Natural Gas and Propane Installation Code.
2. In accordance with the current ANSI Z223.1 / NFPA 54, National Gas Code.
3. In accordance with the current ANSI Z21.47 * CSA 2.3 American National Standard.
IMPORTANT:
Consideration must be given for degradation of building materials by flue gases. Sidewall termination may require sealing or shield-
ing of building surfaces with a corrosion resistant material to protect against combustion product corrosion. Consideration must be given to wind
direction to prevent flue products and/or condensate from being blown against the building surfaces. If a metal shield is used, it must be a stainless
steel material at a minimum dimension of 20 in. (51 cm). It is recommended that a retaining type collar be used that is attached to the building sur-
face to prevent movement of the vent pipe.
