7
LENNOX HEARTH PRODUCTS • MERIT PLUS
®
DIRECT VENT GAS FIREPLACES (MPD33/35/40/45) • INSTALLATION INSTRUCTIONS
NOTE: DIAGRAMS & ILLUSTRATIONS ARE NOT TO SCALE.
Figure 7 - Exterior Horizontal Vent Termination Clearance Requirements
EXTERIOR HORIZONTAL VENT TERMINATION CLEARANCE REQUIREMENTS
V
V
V
V
V
F
C
Fixed
Closed
Window
Operable
Window
B
B
A
B
H
M
I
= Area where Termination is not Permitted
= Air Supply Inlet
X
= Vent Termination
V
D
V
3 ft.
3 ft.
= 9” in U.S.
= 12” in Canada
V
L
B
J
X
V
A
G
Inside
Corner Detail
B
C
C
C
*18”
Ventilated Soffit
Horizontal
Termination
Detail D
Exterior Wall
6”
Inside Corner
*
See Item D in the Text Below.
V
P
V
O
N
N
Q
NOTE: Local Codes Or Regulations
May Require Different Clearances.
NOTE: Location Of The Vent Termination
Must Not Interfere With Access To The
Electrical Service.
E
K
X
Minimum Clearances
Canadian Installation *
US Installation **
A = Clearance above grade, veranda, porch, deck
or balcony.
12" (30 cm) *
12" (30 cm) **
B = Clearance to window or door that may be opened 6" (15.2 cm) for appliances < 10,000 BTU/hr (3kW),
12" (30 cm) for appliances > 10,000 BTU/hr (3kW)
6" (15.2 cm) for appliances < 10,000 BTU/hr (3kW),
9" (23 cm) for appliances > 10,000 BTU/hr (3kW) and
< 50,000 BTU/hr (15kW), 12" (30 cm) for appliances >
50,000 BTU/hr (15kW)**
C = Clearance to permanently closed window
12" (305 mm) recommended to prevent window conden-
sation
9" (229 mm) recommended to prevent window con-
densation
d = Vertical clearance to ventilated soffit located
above the terminal within a horizontal distance of
18" (458 mm)
18" (458 mm)
18" (458 mm)
E = Clearance to unventilated soffit
12" (30 cm)
12" (30 cm)
F = Clearance to outside corner
5" (12.7 cm)
5" (12.7 cm)
G = Clearance to inside corner
2" (5.08cm) minimum - SV4.5HT-2 •
6" (15.2cm) minimum - SV4.5HTSS •
2" (5.08cm) minimum - SV4.5HT-2 •
6" (15.2cm) minimum - SV4.5HTSS •
H = Clearance to each inside of center line extended
above meter / regulator assembly
3 feet (91 cm) within a height of 15 feet above the meter /
regulator assembly *
3 feet (91 cm) within a height of 15 feet above the meter
/ regulator assembly **
I = Clearance to service regulator vent outlet
3 feet (91 cm) *
3 feet (91 cm) **
J = Clearance to non-mechanical air supply inlet
to building or the combustion air inlet to any other
appliance
6" (15.2 cm) for appliances < 10,000 BTU/hr (3kW), 12"
(30 cm) for appliances > 10,000 BTU/hr (3kW)
6" (15.2 cm) for appliances < 10,000 BTU/hr (3kW), 9"
(23 cm) for appliances > 10,000 BTU/hr (3kW) and <
50,000 BTU/hr (15kW), 12" (30 cm) for appliances >
50,000 BTU/hr (15kW)**
K = Clearance to mechanical air supply inlet
6 feet (1.83 meters) *
3 feet (91 cm) above, if within 10 feet (3 m) horizontally**
L = Clearance above paved sidewalk or paved
driveway located on public property
7 feet (2.13 m) ‡
7 feet (2.13 m) ‡
M = Clearance under veranda, porch, deck or
balcony
12" (30 cm) * ‡
12" (30 cm) ‡
N = depth of Alcove (Maximum)
6 feet (1.83m)*
6 feet (1.83m)**
O = Clearance to Termination (Alcove)
6" (15.2mm)*
6" (15.2mm)**
P = Width of Alcove (Minimum)
3 feet (91cm)*
3 feet (91cm)**
Q = Clearance to Combustible Above (Alcove)
18" (457mm)*
18" (457mm)**
* In accordance with the current CAN/CGA-B149.1 National Gas and Propane Installation Code.
** In accordance with the current ANSI Z223.1 / NFPA 54 National Fuel Codes.
‡ A vent shall not terminate directly above a sidewalk or paved driveway which 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 2 sides beneath the floor.
• 2" Clearance to Non-Combustibles for SV4.5HT-2 Only.
