Setting The Unit - Lennox 12HPB Series Installation Instructions Manual

Setting the Unit

CAUTION
In order to avoid injury, take proper precaution when
lifting heavy objects.
CAUTION
Sharp sheet metal edges can cause injury. When
installing the unit, avoid accidental contact with
sharp edges.
Outdoor units operate under a wide range of weather con-
ditions; therefore, several factors must be considered
when positioning the outdoor unit. The unit must be posi-
tioned to give adequate clearances for sufficient airflow
and servicing. A minimum clearance of 24 inches (610 mm)
between multiple units must be maintained. Refer to figure
1 for installation clearances.
Installation Clearances
36
(914 mm)
*NOTE − A service clearance of 30" (762 mm) must be main-
tained on one of the sides adjacent to the control box. Clear-
ance to one of the other three sides must be 36" (914 mm).
Clearance to one of the remaining two sides may be 12" (304
mm) and the final side may be 6" (152 mm).
NOTE − A clearance of 24" (610 mm) must be maintained
between two units.
NOTE − 48" (1219 mm) clearance required on top
of unit. Maximum soffit overhang is 36" (914 mm).
Figure 1
1 − Place a sound-absorbing material, such as Isomode,
under the unit if it will be installed in a location or posi-
tion that will transmit sound or vibration to the living
area or adjacent buildings.
2 − Install the unit high enough above the ground or roof to
allow adequate drainage of defrost water and prevent
ice buildup.
36
(914 mm)
36*
(914 mm)
36*
(914 mm)
Page 3
3 − In heavy snow areas, do not locate the unit where drift-
ing will occur. The unit base should be elevated above
the depth of average snows.
NOTE − Elevation of the unit may be accomplished by
constructing a frame using suitable materials. If a sup-
port frame is constructed, it must not block drain holes
in unit base.
4 − When installed in areas where low ambient tempera-
tures exist, locate unit so winter prevailing winds do not
blow directly into outdoor coil.
5 − Locate unit away from overhanging roof lines which
would allow water or ice to drop on, or in front of, coil or
into unit.
Slab Mounting − Figure 2
When installing a unit at grade level, the top of the slab
should be high enough above the grade so that water from
higher ground will not collect around the unit. See figure 2.
Slab should have a slope tolerance away from the building
of 2 degrees or 2 inches per 5 feet (51 mm per 1524 mm).
This will prevent ice from building up under the unit during a
defrost cycle. Refer to the roof mounting section for barrier
construction if the unit must face prevailing winter winds.
Slab Mounting At Ground Leve
structure
Mounting slab must slope
away from building.
Figure 2
Roof Mounting − Figure 3
Install the unit a minimum of 6 inches (152 mm) above the
roof surface to avoid ice build−up around the unit. Locate
the unit above a load bearing wall or area of the roof that
can adequately support the unit. Consult local codes for
rooftop applications.
l
discharge air
ground level