10 NOTE: DIAGRAMS & ILLUSTRATIONS ARE NOT TO SCALE.
FIREPLACE AND FRAMING SPECIFICATIONSVent Size
Coaxial DV
Vent Size
4-1/2" Inner
7-1/2" Outer
Vertical Venting Through the Ceiling:Frame ceiling opening - Use a plumb line from the ceiling above the appliance to locate center of the vertical run. Cut and/or frame an opening, 10-1/2" x 10-1/2" (267 mm x 267 mm) inside dimensions, about this center mark (see Figure 18).
Notes
Diagrams, illustrations and photo-
graphs are not to scale – consult
installation instructions. Product
designs, materials, dimensions,
specifications, colors and prices are
subject to change or discontinuance
without notice.
Input (BTU/HR) - MV & Electronic
Natural & Propane Gas
Models Input Rate (BTU / HR)
MLDVT-30N 13,500
MLDVT-30P 12,500
MLDVT-35N 16,000
MLDVT-35P 15,000
MLDVT-40N 20,000
MLDVT-40P 20,000
MLDVT-45N 23,000
MLDVT-45P 22,000
Efficiencies (%)
Model Natural Gas Propane
AFUE EnerGuide (P4) AFUE EnerGuide (P4)
MLDVT-30 57 55.6 58 56.1
MLDVT-35 57.5 55.6 59.0 58.1
MLDVT-40 62 61 62.3 59.5
MLDVT-45 63 60 64 62
Viewable Glass Size
30" Model 24-1/4" Wide
20-1/4" High
35" Model 29-1/4" Wide
20-1/4" High
40" Model 34-1/4" Wide
25-1/4" High
45" Model 39-1/4" Wide
25-1/4" High
Figure 13

Framing

A

BC

7
(178)
5-1/8
12-1/8
(308)
10-1/2
(267)

D

(130)

A

1/2
Framing Dimensions
Model No. A B C D
MLDVT-30 in. 30-1/4 35-1/4 39-1/4 16
mm 768 895 997 406
MLDVT-35 in. 35-1/4 35-1/4 39-1/4 16
mm 895 895 997 406
MLDVT-40 in. 40-1/4 40-1/4 44-1/4 16
mm 1022 1022 1124 406
MLDVT-45 in. 45-1/4 40-1/4 44-1/4 16
mm 1149 1022 1124 406
.oNledoM E F G H JKL M
.ni
mm
MLDVT-35
32-1/4
819
28-1/8
715
23-1/4
587
32
813
35-1/4
892
25
635
12-1/2
317
33
838
.ni
mm
MLDVT-40 37-1/4
946
33-1/8
841
28-1/4
714
37
940
40-1/4
1019
30
762
15
381
38
965
.ni
mm
MLDVT-30
32-1/4
819
28-1/8
715
23-1/4
587
27
686
30-1/4
768
20
508
10
354
28
711
.ni
mm
MLDVT-45 37-1/4
946
33-1/8
841
28-1/4
714
42
1067
45-1/4
1149
35
889
17-1/2
445
43
1092
Vent Framing - Top Vent With One 90° ElbowDimension D is the required framing depth when the finish material (drywall) thickness is 1/2 in. (13mm)Inches (millimeters)Framing should be constructed of 2x4 or larger lumber.
LENNOX HEARTH PRODUCTS • MERIT® SERIES DIRECT-VENT GAS FIREPLACES • MODELS MLDVT-30/35/40/45 • INSTALLATION INSTRUCTIONS
J
Front View
HGFEMKL
Top View
*CONCENTRIC FLUE
FLUE - 4-1/2 (114)
COMBUSTION AIR
- 7-1/2 (190)
9-1/4 (235)
1/2
(13)
16 (406)
1-5/8(42)
NOTE - Eyebrow
hood shown.
GAS INLET
KNOCKOUT
(Other Side)
Right Side View
5-7/8
(149)
3 (76)
3 (76)
9-1/2
(241)
ELECTRICAL INLET
KNOCKOUT - 2-3/4 X 2
(70 X 51) COVER PLATE
(With KNOCKOUT -
Right Side Only)
OPTIONAL
ELECTRICAL
INLET KNOCKOUT,
REQUIRING A FIELD
PROVIDED
JUNCTION BOX
(Either Side)
NOTE: It is recommended that the gas be stubbed in from the left
side only.