Vermont Casting BHDR36 - Manual (Page 15)

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BELOW GRADE INSTALLATIONS
When it is not possible to meet the required vent termi-
nal clearances of 12 inches (305mm) above grade level
a model #7DVSKS vent kit is recommended. It allows
installation depth of down to 7 inches (178mm) below
grade level. The 7 inches is measured from the centre
of the horizontal vent pipe as it penetrates through the
wall.
If venting system is installed below ground,
we recommend a window well with adequate
and proper drainage.
Ensure sidewall venting clearances are observed.
The maximum horizontal run with 24" vertical
rise is 36" (915mm) from the back of the
fireplace to the face of the exterior wall. See
vent graph (Fig. 21) for extended horizontal
run if the vertical exceeds 24".
1. Establish vent hole through the wall. See page 14
2. Remove soil to a depth of approximately 16" below
base of snorkel. Install window well (not supplied).
Refill hole with 12" of coarse gravel leaving a clear-
ance of approximately 4" below snorkel. (Fig. 30)
3. Install vent system. See page 15, Steps 2 through
5.
4. Ensure a watertight seal is made around the vent
pipe coming through the wall.
5. Apply high temperature sealant caulking (supplied)
around the 4 and 7 inch 7DVSKS's snorkel collars.
6. Slide into vent pipe and secure to the wall.
7. Level the soil so as to maintain a 4" clearance below
snorkel (Fig. 30).
DO NOT BACK FILL AROUND SNORKEL.
SOIL SHOULD NOT BE LESS THAN 4"
BELOW SNORKEL.
FOUNDATION
RECESS
SNORKEL
SCREWS
WALL
SCREWS
SHEET METAL
WATERTIGHT
SEAL
AROUND
PIPE
If the foundation is recessed, use recess brackets (not
supplied) for securing lower portion of the snorkel. Fasten
brackets to wall first and then secure to snorkel with self
drilling #8 x 1/2 sheet metal screws. It will be necessary to
extend vent pipes out as far protruding wall face (Fig. 31).
Fig. 30
Fig. 31
MAXIMUM
10 FT
(3048mm)
PIPE STRAPS
EVERY 3'
(914mm)
MINIMUM
8 FT./
MAXIMUM
40 FT.
VERTICAL
RISE
VERTICAL THROUGH THE
ROOF APPLICATIONS
This Gas Fireplace has been approved for,
a) Vertical installations up to 40 feet (12 metres) in height.
Up to a 10 ft. horizontal vent run can be installed within
the vent system using a maximum of three 90
o elbows.
b) Up to two 45 o elbows may be used within the horizontal
run. For each 45 o elbow used on the horizontal level
the maximum horizontal length must be reduced by 18
inches.
Example: Maximum horizontal length
0 - 45 o elbows 10 ft.
1 - 45 o elbows 8.5 ft.
2 - 45 o elbows 7 ft.
Fig. 32
GRAVEL
DRAIN
FIRESTOP
FOUNDATION WALL
WINDOW WELL
7DVSKS
(SNORKEL)
GROUND
A minimum of 24"/608mm
vertical pipe must be installed
when using the 7DVSKS kit.
The 22" vertical rise (center to
center) of the snorkel may be
included for calculation of max.
horizontal run.
*
SCREWS MINIMUM
4" CLEARANCE
ZERO CLEARANCE
SLEEVE IF REQUIRED
7DVRT90
7DVRT90
*