VENT TERMINATION CLEARANCES

FOR NON−DIRECT VENT INSTALLATIONS IN THE USA AND CANADA

INSIDE CORNER

DETAIL

 

 

 

 

G

 

 

 

 

 

 

A

 

H

D

 

 

 

 

 

 

 

 

 

 

 

 

E

 

 

 

 

 

 

 

B

 

 

 

 

 

L

C

 

B

B

I

 

 

 

 

Fixed

 

 

 

 

 

Operable

 

 

 

 

Fixed

Closed

M

 

 

 

 

 

 

F

Closed

 

 

 

 

 

Operable

 

 

 

 

 

 

 

 

 

 

 

B

 

K

 

 

 

 

 

J

 

 

 

 

A

 

 

 

 

 

 

 

 

 

B

 

 

 

 

 

 

VENT TERMINAL

 

AIR SUPPLY INLET

 

AREA WHERE TERMINAL

 

 

 

 

IS NOT PERMITTED

 

 

 

 

 

 

 

 

 

 

US Installations1

 

Canadian Installations2

A =

 

Clearance above grade, veranda,

 

12 inches (305mm) or 12 in. 305mm)

12 inches (305mm) or 12 in. 305mm)

 

 

porch, deck or balcony

 

above average snow accumulation.

above average snow accumulation.

B =

 

Clearance to window or

4 feet (1.2 m) below or to side of opening;

6 inches (152mm) for appliances <10,000

 

 

door that may be opened

Btuh (3kw), 12 inches (305mm) for

 

 

 

1 foot (30 cm) above opening

 

 

 

 

appliances > 10,000 Btuh (3kw) and

 

 

 

 

 

 

 

 

 

 

 

 

<100,000 Btuh (30kw), 36 inches (.9m)

 

 

 

 

 

 

for appliances > 100,000 Btuh (30kw)

C =

 

Clearance to permanently

 

* 12"

 

* 12"

 

 

closed window

 

 

 

 

 

 

 

 

D =

Vertical clearance to ventilated soffit

 

 

 

 

 

located above the terminal within a

* Equal to or greater than soffit depth.

* Equal to or greater than soffit depth.

 

horizontal distance of 2 feet (mm)

 

 

 

 

 

from the center line of the terminal

 

 

 

 

E =

Clearance to unventilated soffit

* Equal to or greater than soffit depth.

* Equal to or greater than soffit depth.

 

F =

Clearance to outside corner

* No minimum to outside corner

* No minimum to outside corner

G = Clearance to inside corner

*

*

 

 

H = Clearance to each side of center line ex-

* 3 feet (.9m) within a height 15 feet (4.5m)

3 feet (.9m) within a height 15 feet (4.5m)

 

tended above meter / regulator assembly

above the meter / regulator assembly

above the meter / regulator assembly

 

I =

Clearance to service regulator

* 3 feet (.9m)

3 feet (.9m)

 

vent outlet

 

 

 

 

J =

Clearance to non−mechanical air

 

6 inches (152mm) for appliances <10,000

 

supply inlet to building or the com-

4 feet (1.2 m) below or to side of opening;

Btuh (3kw), 12 inches (305mm) for

 

bustion air inlet to any other ap-

1 foot (30 cm) above opening

appliances > 10,000 Btuh (3kw) and

 

pliance

 

<100,000 Btuh (30kw), 36 inches (.9m)

 

 

 

for appliances > 100,000 Btuh (30kw)

 

K =

Clearance to mechanical air sup-

3 feet (.9m) above if within 10 feet

6 feet (1.8m)

 

ply inlet

(3m) horizontally

 

 

 

L =

Clearance above paved sidewalk or

7 feet (2.1m)

7 feet (2.1m)

 

paved driveway located on public property

 

 

 

 

M =

Clearance under veranda, porch,

*12 inches (305mm)

12 inches (305mm)

 

deck or balcony

 

 

 

 

 

 

 

 

1In accordance with the current ANSI Z223.1/NFPA 54 Natural Fuel Gas Code

2In accordance with the current CSA B149.1, Natural Gas and Propane Installation Code

aved driveway that is located

between two single family dwellings and serves both dwellings.

sides beneath the floor. Lennox recommends avoiding this location if possible.

*For clearances not specified in ANSI Z223.1/NFPA 54 or CSA B149.1, clearance will be in accordance with local installation codes and the re- quirements of the gas supplier and these installation instructions."

FIGURE 23

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Image 19
Lennox International Inc MERIT SERIES GAS FURNACE DOWNFLOW AIR DISCHARGE Inside Corner Detail, Inches 305mm or 12 in mm