13
NOTE: DIAGRAMS & ILLUSTRATIONS ARE NOT TO SCALE.
Note: Convert inches into metric equivalent
measurement, as follows:
Millimeters (mm) = Inches x 25.4
Centimeters (cm) = Inches x 2.54
Meters (M) = Inches x .0254
TRAHCHTGNELNOITCESTNEV
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5.4 573.0 1 0 0 0 0 1
9 57.0 2 0 0 0 0 2
5.01 578.0 0 1 0 0 0 1
51 52.1 1 1 0 0 0 2
5.22 578.1 0 0 1 0 0 1
5.13 526.2 0 3 0 0 0 3
5.43 578.2 0 0 0 1 0 1
5.73 521.3 1 1 1 0 0 3
5.34 526.3 0 2 1 0 0 3
54 57.3 0 0 2 0 0 2
5.64 578.3 0 0 0 0 1 1
15 52.4 1 0 0 0 1 2
5.55 526.4 0 1 2 0 0 3
75 57.4 0 0 1 1 0 2
5.76 526.5 0 0 3 0 0 3
96 57
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5.37 521.6 1 0 0 2 0 3
5.97 526.6 0 1 0 2 0 3
18 57.6 0 0 0 1 1 2
5.19 526.7 0 0 2 0 1 3
39 57.7 0 0 0 0 2 2
5.79 521.8 1 0 0 0 2 3
5.301 526.8 0 0 0 3 0 3
801 9 1 0 0 3 0 4
711 57.9 1 0 5 0 0 6
5.811 578.9 1 1 0 3 0 5
621 5.01 0 0 1 3 0 4
5.031 578.01 1 0 1 3 0 5
531 52.11 0 0 6 0 0 6
5.931 526.11 0 0 0 0 3 3
5.241 578.11 1 0 0 4 0 5
441 21 1 0 0 0 3 4
5.451 578.21 1 1 0 0 3 5
5.061 573.31 0 2 0 0 3 5
5.271 573.41 0 0 0 5 0 5
771 57.41 1 0 0 5 0 6
681 5.51 0 0 0 0 4 4
5.691 573.61 0 1 0 0 4 5
702 52.71 0 0 0 6 0 6
5.112 526.71 1 0 0 6 0 7
5.712 521.81 0 1 0 6 0 7
5.922 521.91 0 0 1 6 0 7
5.23
2 573.91 0 0 0 0 5 5
5.142 521.02 0 0 0 7 0 7
642 5.02 1 0 0 7 0 8
252 12 0 1 0 7 0 8
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9 57.0 2 0 0 0 0 2
5.01 578.0 0 1 0 0 0 1
51 52.1 1 1 0 0 0 2
5.22 578.1 0 0 1 0 0 1
5.13 526.2 0 3 0 0 0 3
5.43 578.2 0 0 0 1 0 1
5.73 521.3 1 1 1 0 0 3
5.34 526.3 0 2 1 0 0 3
54 57.3 0 0 2 0 0 2
5.64 578.3 0 0 0 0 1 1
15 52.4 1 0 0 0 1 2
5.55 526.4 0 1 2 0 0 3
75 57.4 0 0 1 1 0 2
5.76 526.5 0 0 3 0 0 3
96 57
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5.37 521.6 1 0 0 2 0 3
5.97 526.6 0 1 0 2 0 3
18 57.6 0 0 0 1 1 2
5.19 526.7 0 0 2 0 1 3
39 57.7 0 0 0 0 2 2
5.79 521.8 1 0 0 0 2 3
5.301 526.8 0 0 0 3 0 3
801 9 1 0 0 3 0 4
711 57.9 1 0 5 0 0 6
5.811 578.9 1 1 0 3 0 5
621 5.01 0 0 1 3 0 4
5.031 578.01 1 0 1 3 0 5
531 52.11 0 0 6 0 0 6
5.931 526.11 0 0 0 0 3 3
5.241 578.11 1 0 0 4 0 5
441 21 1 0 0 0 3 4
5.451 578.21 1 1 0 0 3 5
5.061 573.31 0 2 0 0 3 5
5.271 573.41 0 0 0 5 0 5
771 57.41 1 0 0 5 0 6
681 5.51 0 0 0 0 4 4
5.691 573.61 0 1 0 0 4 5
702 52.71 0 0 0 6 0 6
5.112 526.71 1 0 0 6 0 7
5.712 521.81 0 1 0 6 0 7
5.922 521.91 0 0 1 6 0 7
5.23
2 573.91 0 0 0 0 5 5
5.142 521.02 0 0 0 7 0 7
642 5.02 1 0 0 7 0 8
252 12 0 1 0 7 0 8
TRAHCHTGNELNOITCESTNEV
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672 32 0 0 0 8 0 8
972 52.32 0 0 0 0 6 6
5.082 573.32 1 0 0 8 0 9
5.982 521.42 0 1 0 0 6 7
5.103 521.52 0 0 1 0 6 7
5.013 578.52 0 0 0 9 0 9
5.523 521.72 0 0 0 0 7 7
033 5.72 1 0 0 0 7 8
543 57.82 0 0 0 01 0 01
5.943 521.92 1 0 0 01 0 11
273 13 0 0 0 0 8 8
5.973 526.13 0 0 0 11 0 11
5.814 578.43 0 0 0 0 9 9
564 57.83 0 0 0 0 01 01
5.574 526.93 0 1 0 0 01 11
084 04 1 1 0 0 01 11
294 14 1 0 1 0 01 21
5.994 526.14 0 0 0 1 01 11
405 24 1 0 0 1 01 21
5.115 526.24 0 0 0 0 11 11
5.025 573.34 0 2 0 1 11 41
135 52.44 0 2 2 0 11 51
5.835 578.44 1 0 0 2 11 41
945 57.54 1 0 2 1 11 51
855 5.64 0 0 0 0 21 21
5.265 578.64 1 0 0 0 21 31
5.865 573.74 0 1 0 0 21 31
375 57.74 1 1 0 0 21 41
5.085 573.84 0 0 1 0 21 31
5.985 521.94 0 1 2 2 01 51
5.595 526.94 1 1 1 0 21 51
5.406 573.05 0 0 0 0 31 31
516 52.15 0 1 0 0 31 41
5.526 521.25 0 2 0 0 31 51
5.136 526.25 1 0 1 0 31 51
5.736 521.35 0 1 1 0 31 51
156 52.45 0 0 0 0 41 41
5.556 526.45 1 0 0 0 41 51
276 65 0 2 0 0 41 61
876 5.65 1 0 1 0 41 61
5.886 573.75 1 1 1 0 41 71
5.796 521.85 0 0 0 0 51 51
207 5.85 1 0 0 0 51 61
5.217 573.95 1 1 0 0 51 71
027 06 0 0 1 0 51 61
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672 32 0 0 0 8 0 8
972 52.32 0 0 0 0 6 6
5.082 573.32 1 0 0 8 0 9
5.982 521.42 0 1 0 0 6 7
5.103 521.52 0 0 1 0 6 7
5.013 578.52 0 0 0 9 0 9
5.523 521.72 0 0 0 0 7 7
033 5.72 1 0 0 0 7 8
543 57.82 0 0 0 01 0 01
5.943 521.92 1 0 0 01 0 11
273 13 0 0 0 0 8 8
5.973 526.13 0 0 0 11 0 11
5.814 578.43 0 0 0 0 9 9
564 57.83 0 0 0 0 01 01
5.574 526.93 0 1 0 0 01 11
084 04 1 1 0 0 01 11
294 14 1 0 1 0 01 21
5.994 526.14 0 0 0 1 01 11
405 24 1 0 0 1 01 21
5.115 526.24 0 0 0 0 11 11
5.025 573.34 0 2 0 1 11 41
135 52.44 0 2 2 0 11 51
5.835 578.44 1 0 0 2 11 41
945 57.54 1 0 2 1 11 51
855 5.64 0 0 0 0 21 21
5.265 578.64 1 0 0 0 21 31
5.865 573.74 0 1 0 0 21 31
375 57.74 1 1 0 0 21 41
5.085 573.84 0 0 1 0 21 31
5.985 521.94 0 1 2 2 01 51
5.595 526.94 1 1 1 0 21 51
5.406 573.05 0 0 0 0 31 31
516 52.15 0 1 0 0 31 41
5.526 521.25 0 2 0 0 31 51
5.136 526.25 1 0 1 0 31 51
5.736 521.35 0 1 1 0 31 51
156 52.45 0 0 0 0 41 41
5.556 526.45 1 0 0 0 41 51
276 65 0 2 0 0 41 61
876 5.65 1 0 1 0 41 61
5.886 573.75 1 1 1 0 41 71
5.796 521.85 0 0 0 0 51 51
207 5.85 1 0 0 0 51 61
5.217 573.95 1 1 0 0 51 71
027 06 0 0 1 0 51 61
SV4.5CGV-1Termination SV4.5FA ORSV4.5FB FlashingAND SV4.5SCSTORM COLLARSV4.5VFFirestop/SpacerSV4.5L6/12/24/36/48Vent Sections60' Max(18.3 M)1" (25.4 mm)MinimumClearance toCombustiblesWhen using Secure Flexuse Firestop/SpacerSF4.5VF

Effective Vent Length

Model Effective Length
SV4.5L6 4-1/2"
SV4.5L12 10-1/2"
SV4.5L24 22-1/2"
SV4.5L36 34-1/2"
SV4.5L48 46-1/2"

Table 7

Figure 17

LENNOX HEARTH PRODUCTS • MERIT® SERIES DIRECT-VENT GAS FIREPLACES • MODELS MLDVT-30/35/40/45 • INSTALLATION INSTRUCTIONS

VERTICAL TERMINATION SYSTEMS (ROOF)

See Figure 17 on Page 13 and Figures 25 through

27 on Pages 16 and 17 and their associated

Vertical Vent Tables which illustrate the various

vertical venting configurations that are possible

for use with these appliances. Secure Vent™

pipe applications are shown in these Figures;

Secure Flex™ pipe may also be used. A Vertical

Vent Table summarizes each system’s minimum

and maximum vertical and horizontal length

values that can be used to design and install the

vent components in a variety of applications.

Both these vertical vent systems terminate

through the roof. The minimum vent height

above the roof and/or adjacent walls is speci-

ed in ANSI Z223.1-(latest edition) (In Canada,

the current CAN/CSA-B149.1 installation code)

by major building codes. Always consult your

local codes for specific requirements. A general

guide to follow is the Gas Vent Rule (refer to

Figure 5 on Page 6).

A vent restrictor may need to be installed when

vertical termination is used. See Installation

of Vent Restrictor on Page 14 for guidelines.

Vertical (Straight) Installation (Figure 17)

Determine the number of straight vent sections

required. 4-1/2" (114 mm), 10-1/2" (267 mm),

22-1/2" (572 mm), 34-1/2" (876 mm) and 46-

1/2" (1181 mm) net section lengths are available

(see Tables on this page and Page 35 - Vent

Sections). It is recommended that you plan the

vent lengths so that a joint does not occur at

the intersection of ceiling or roof joists. Refer

to the Vent Section Length Chart.