Vent Termination Clearances - Lennox MPDT33RNM Installation Instructions Manual

LENNOX HEARTH PRODUCTS • MERIT PLUS

VENT TERMINATION CLEARANCES

These instructions should be used as a
guideline and do not supersede local
codes in any way. Install venting according
to local codes, these instructions,
the current National Fuel Gas Code
(ANSI-Z223.1-2009) in the USA or the
current standards of CAN/CSA-B149.1 in
Canada.
Vertical Vent Termination Clearances
Terminate multiple vent terminations
according to the installation codes listed
above and Figures 4 and 5.
12 in.
(305mm)
Minimum
Figure 4: Multiple Terminations
6
DIRECT VENT GAS FIREPLACES (MPD33/35/40/45) • INSTALLATION INSTRUCTIONS
®
Vertical Vent Termination Clearances
TERMINATION HEIGHTS FOR VENTS ABOVE
FLAT OR SLOPED ROOFS
Horizontal Overhang
2 FT
MIN.
2 FT MIN.
Lowest
Discharge
Vent Opening
Termination
H*
Storm Collar
12
Flashing
Roof Pitch is X/12
1 inch (25.4 mm) Minimum
Clearance to Combustibles
Concentric
*H = MINIMUM HEIGHT FROM ROOF TO
Vent Pipe
LOWEST DISCHARGE OPENING OF VENT
Figure 5: Termination Heights for Vents
Above Flat or Sloped Roofs
Horizontal Vent Termination Clearances
The horizontal vent termination must have a minimum of 6 in. (152 mm) clearance to any
overhead combustible projection of 2 1/2 in. (64 mm) or less, see Figure 6. For projections
exceeding 2 1/2 in. (64 mm), see Figure 6. For additional vent location restrictions, refer to
Figure 7 on Page 7.
Horizontal Vent Termination Clearances
Combustible Projection
2-1/2 inches or less in length
Combustible Projection greater
than 2-1/2 inches in length
Ventilated
Soffit
Unventilated
Soffit
18" 12"
(457 mm)
(305 mm)
Side Elevation View
Termination Kit
Figure 6: Horizontal Vent
Termination Clearances
NOTE: DIAGRAMS & ILLUSTRATIONS ARE NOT TO SCALE.
The vent / air intake termination clearances
above the high side of an angled roof are as
shown in the following chart:
Termination Heights For Vents
Above Flat Or Sloped Roofs
Vertical
Ref. NFPA 54 / ANSI Z223.1-2009
Wall
Roof Pitch
Flat–6/12
6/12–7/12
X 7/12–8/12
8/12–9/12
9/12–10/12
10/12–11/12
11/12–12/12
12/12–14/12
14/12–16/12
16/12–18/12
18/12–20/12
20/12–21/12
All horizontal terminations
may be located as close as
6" (152mm) to any
(non-combustible and
combustible) exterior
sidewall. This distance
may be decreased to 2"
(51mm) for non- -
6"
combustible exterior
(152 mm)
sidewalls only, if the
SV4.5HT-2 termination
is used.
Note: See Figure 34 on Page 20 for the exterior wall recess
allowances of the square horizontal termination.
*H (ft) *H (m)
1.0 0.3
1.25 0.38
1.5 0.46
2.0 0.61
2.5 0.76
3.25 0.99
4.0 1.22
5.0 1.52
6.0 1.83
7.0 2.13
7.5 2.29
8.0 2.44
Termination Kit