Buried Refrigerant Pipe Protection; Securing The Outdoor Unit - Lennox MHB Series Installation, Instruction And Service Manual

• In heavy snow areas, do not place the unit where drift­
ing will occur as illustrated in "Figure 22. Outdoor Unit
Air Flow Obstructed by Snow".
• Carefully consider how to manage defrost water dis­
posal to prevent ice from blocking walkways or creat­
ing a safety hazard near the outdoor unit as illustrated
in "Figure 23. Avoid Defrost Water Ice Hazard".
Air Outlet
Figure 21. Outdoor Unit on Brackets above Snow
79 in
2007 mm
Figure 22. Outdoor Unit Air Flow Obstructed by
Figure 23. Avoid Defrost Water Ice Hazard

Buried Refrigerant Pipe Protection

• All refrigerant lines must be insulated regardless of if
it is buried.
• In addition to insulating each line of piping, buried
lines must rest inside a sealed, watertight conduit.
• The conduit must be designed so it cannot collect and
retain water.
Air Inlet
Line
12 in
305 mm
Air Inlet
Air Outlet
Snow

Securing the Outdoor Unit

Slab or Roof Mounting
Install the unit a minimum of 4 inches (102 mm) above
the roof or ground surface to avoid debris build­up around
the unit. Place the unit above a load bearing wall or area
of the roof that can adequately support the unit. Consult
local codes for rooftop applications.
Roof Damage!
This system contains both refrigerant and oil. Some
rubber roofing material may absorb oil. This will cause
the rubber to swell when it comes into contact with oil.
The rubber will then bubble and could cause leaks.
Protect the roof surface to avoid exposure to refrigerant
and oil during service and installation. Failure to follow
this notice could result in damage to roof surface.
Securing Outdoor Unit to Slab, Frame, or Rails
If the outdoor unit is installed on a field-provided slab or
frame, use lag bolts or equivalent to secure the outdoor
unit to the slab or frame.
Figure 24. Securing Outdoor Unit to Slab
Figure 25. Securing Outdoor Unit to Rails
Securing Outdoor Unit to Hanging Brackets
If the outdoor unit is installed on field-provided wall
mounting brackets, use lag bolts or equivalent to secure
the outdoor unit to the bracket. Minimum rear clearance
can be reduced to 6 inches (152 mm) when mounted
on brackets and with no obstructions on the other three
sides. Allow for moisture disposal when placing units
above one another.
10
CAUTION
Four Field-provided Anchor Bolts
Four Field-Provided
Anchor Bolts