Lennox LSM40ST-N Installation Instructions Manual page 7

LENNOX HEARTH PRODUCTS • MONTEBELLO
D
D
D
36"
(91.4 cm)
Center Line of
horizontal
36"
Termination
36"
(91.4 cm)
(91.4 cm)
Inside Corner
See Item "D" in table below.
B
F
V
B
L
B
V
F
V
V
L
L
V
V
A
Clearance Description
A = Clearance above grade, veranda, porch,
deck, or balcony.
B = Clearance to window or door that may be
opened.
C = Clearance to permanently closed window.
D = Vertical clearance to ventilated soffit
located above the terminal within a
horizontal distance of 36 in (91.4 cm)
from center line of terminal.
E = Clearance to unventilated soffit.
F = Clearance to outside corner.
G = Clearance to inside corner.
H = Clearance to each inside of center line
extended above meter/regulator assembly.
I = Clearance to service regulator vent outlet.
J = Clearance to non-mechanical air supply
inlet to building or combustion air inlet to
any other appliance.
K = Clearance to mechanical air supply inlet.
L = Clearance above paved sidewalk or paved
driveway located on public property.
M = Clearance under veranda, porch, deck, or
balcony.
 In accordance with the current ANSI Z223.1 / NFPA 54 National Fuel Codes (latest editions).
 In accordance with the current CAN/CSA-B149.1 Installation Code (latest editions).
 A vent shall not terminate directly above a sidewalk or paved driveway that is located between two single-family dwellings and serves both dwellings.
 Only permitted if veranda, porch, deck, or balcony is fully open on a minimum of two sides beneath the floor.
Figure 5
SEE-THROUGH DIRECT-VENT GAS FIREPLACES (LSM40ST-N / LSM40ST-P) • INSTALLATION INSTRUCTIONS
®
EXTERIOR hORIZONTAL VENT TERMINATION CLEARANCE REQUIREMENTS
Exterior Wall
Ventilated
Soffit
[DETAIL]
Fixed Closed
V
Window
C
Fixed Closed
F
Fixed Closed
V
V
Window
Window
B
C
C
V
V V
C
A
C C
C
V
B
C
A
C C
C C
MINIMUM CLEARANCES
US Installation 
18 in (46 cm) 
6 in (15.2 cm) for appliances < 10,000 BTU/hr (3kW);
9 in (23 cm) for appliances > 10,000 BTU/hr (3kW)
and < 50,000 BTU/hr (15kW);
12 in (30 cm) for appliances > 50,000 BTU/hr (15kW).
9 in (229 mm) recommended to prevent window
condensation.
24 in (61 cm)
24 in (61 cm)
5 in (12.7 cm)
24 in (61 cm)
3 ft (91.4 cm) within a height of 15 ft above the
meter/regulator assembly. 
3 ft (91.4 cm) 
6 in (15.2 cm) for appliances < 10,000 BTU/hr (3kW);
9 in (23 cm) for appliances > 10,000 BTU/hr (3kW)
and < 50,000 BTU/hr (15kW);
12 in (30 cm) for appliances > 50,000 BTU/hr (15kW).
3 ft (91.4 cm) above, if within 10 ft (3 m) horizontally. 
7 ft (2.13 m) 
18 in (46.0 cm)  
NOTE: DIAGRAMS & ILLUSTRATIONS ARE NOT TO SCALE.
G
V
G
G
A
V
V
[DETAIL]
A
A
Inside Corner
Operable
Window
B
Operable
Operable
Window
V
Window
X
B
J
V
B
B B
J
J
B
B B
B B
NOTE:
• Local codes or regulations may require
different clearances.
• Location of vent termination must NOT
V
interfere with access to electrical service.
V = Vent terminal
X
= Area terminal NOT permitted
X = Air supply inlet
H
= 9" U.S. (12" Canada)
H
H
X
X
M
I
I
Canadian Installation 
18 in (46 cm) 
6 in (15.2 cm) for appliances < 10,000 BTU/hr (3kW);
12 in (30 cm) for appliances > 10,000 BTU/hr (3kW)
and < 100,000 BTU/hr (30kW);
36 in (91.4 cm) for appliances > 100,000 BTU/hr (30kW).
12 in (305 mm) recommended to prevent window
condensation.
24 in (61 cm)
24 in (61 cm)
5 in (12.7 cm)
36 in (91.4 cm)
3 ft (91.4 cm) within a height of 15 ft above the
meter/regulator assembly. 
3 ft (91.4 cm) 
6 in (15.2 cm) for appliances < 10,000 BTU/hr (3kW);
12 in (30 cm) for appliances > 10,000 BTU/hr (3kW)
and < 100,000 BTU/hr (30kW);
36 in (91.4 cm) for appliances > 100,000 BTU/hr (30kW).
6 ft (1.83 m) 
7 ft (2.13 m) 
18 in (46.0 cm) 
= Vent terminal
= Area terminal NOT permitted
V = Vent terminal
= Air supply inlet
= Area terminal NOT permitted
= 9" U.S. (12" Canada)
X = Air supply inlet
= 9" U.S. (12" Canada)
D E
V
D E
D E
V
V
M
V X
M
K
V X
V X
I
K
K
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