Monessen Hearth DIRECT VENT MLDV500 - Manual (Page 21)

75D0004 1
MLDV Series Gas Fireplace VENTING INSTALLATION
BELOW GRADE INSTALLATIONS
When it is not possible to meet the required vent terminal clearances of 1" above grade level, a
snorkel kit is recommended. It allows installation depth down to 7" (178 mm) below grade level.
The 7" (178 mm) is measured from the center of the horizontal vent pipe as it penetrates through
the wall.
Ensure that sidewall venting clearances are observed. If venting system is installed below
ground, we recommend a window well with adequate and proper drainage to be installed
around the termination area.
If installing a snorkel, a minimum 4" vertical rise is necessary. The maximum horizontal run with
the 4” vertical pipe is 36". This measurement is taken from the collar of the fireplace (or transition
elbow) to the face of the exterior wall. Refer to the Sidewall Venting Graph for extended horizontal
run if the vertical exceeds 4".
1. Establish vent hole through the wall.
. Remove soil to a depth of approximately 16" below
base of snorkel. Install drain pipe. Install window well
(not supplied). Refill hole with 1" of coarse gravel
leaving a clearance of approximately 4" below snorkel.
Figure 27
3. Install vent system.
4. Ensure a watertight seal is made around the vent pipe coming through the wall.
5. Apply high temperature sealant caulking (supplied) around the 5" and 8" snorkel collars.
6. Slide the snorkel into the vent pipes and secure to the wall.
7. Level the soil so as to maintain a 4" clearance below snorkel. Figure 27
If the foundation is recessed, use recess brackets (not supplied) for securing lower portion of the
snorkel. Fasten brackets to wall first, then secure to snorkel with self drilling #8 x
1 /

sheet metal
screws. It will be necessary to extend vent pipes out as far as the protruding wall face. Figure 28
FP1965
below grade install
Figure 27 -
Below Grade Installation
Screws
Minimum
4" Clearance
Ground
Window Well
Gravel
Drain
Foundation Wall
Firestop
1"
Minimum
FP1965
FP1966
snorkel
Figure 28 -
Snorkel Installation, Recessed Foundation
Foundation
Recess
Watertight Seal
Around Pipe Sheet Metal
Screws
Wall Screws
Snorkel
FP1966
W
ARNING
• Do not back fill around snorkel.
• A clearance of at least 4” must be maintained
between the snorkel and the soil.