White Mountain Hearth DVCX(36,42)FP30(N,P)-2 Installation Instructions And Owner's Manual page 22

Positioning the Fireplace
Determine the exact position of the appliance so the direct-vent
termination will be centered (if possible) between two studs. This
will avoid any extra framing. All vent kit pipes should be assembled
on the unit after the unit is moved into the final position.
Cutting the Hole
After the fireplace has been positioned in its permanent location,
the hole through the exterior wall of the house can be cut. This hole
must be 12-5/8" (320mm) high x 10-5/8" (270mm) wide with its center
line determined by the amount of vertical rise and horizontal run of
the termination. See Figure 33. When locating the hole it must be
noted that the bottom of the cap must be 12" (305mm) above the
ground level, and top of the cap must be no less than 18" (457mm)
below a combustible projection, and no closer than 9" (229mm) to
any wall running parallel to vent termination.
Page 22
VENTING FIREPLACE
Figure 33
Below Grade Installation
When it is not possible to meet the required vent termination
clearances of 12 inches (305 mm) above grade level, a snorkel kit is
recommended. It allows installation depth down to 7 inches (178 mm)
below grade level. The 7 inches (178 mm) is measured from the
center of the horizontal vent pipe as it penetrates through the wall.
Ensure the 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.
TYPICAL BASEMENT INSTALLATION
CAUTION
Figure 34
35009-2-1015