Reznor R8HE Unit Installation Manual - Manual (Page 8)

8
Clearances to Combustible Materials
These units are certified as combination heating and
cooling equipment for outdoor rooftop or ground level
installations. Units may be installed on combustible
flooring or class A, B, or C roofing material when used
with bottom supply and return air ducts as long as the
following requirements are met:
• If using bottom discharge with return air ducts a roof
curb must be installed prior to unit installation. See
Rigging and Hoisting section for setting of the unit.
• Sufficient clearance for unobstructed airflow through the
outdoor coil must also be maintained in order to achieve
rated performance. For information about locating the
equipment, see
page 5 .
Figure 3. Ground & Rooftop Installation
2”
ROOFTOP INSTALLATION
GROUND LEVEL INSTALLATION
ACCESSORY
ROOF CURB
Ground Level
Ground level installations must be located according to
local building codes or ordinances and these requirements:
• Clearances must be in accordance with those shown
in Figure 1 (page 5) .
• A suitable mounting pad must be provided and be
separate from the building foundation. The pad must be
level to ensure proper condensate disposal and strong
enough to support the unit’s weight. The slab height
must be a minimum of 2” (5cm) above grade and with
adequate drainage. See
Figure 3 .
• Remove and discard the horizontal Supply and Return
duct covers located on the rear of the unit. Form duct
attachment flanges by bending the sheet metal outward
90 degrees along the perforated lines.
• Firmly attach ductwork directly to these flanges with
screws or other approved mechanical connections and
not to the Supply/Return air panels to avoid damage to
internal components of the equipment. Use approved
duct sealing methods to ensure an air and watertight
seal is achieved.
Rooftop
Rooftop installations must be located according to local
building codes or ordinances and these requirements:
• The roof must be capable of handling the weight of the
unit. Reinforce the roof if necessary For unit weights,
see
Table 7 (page 27) .
• The appropriate accessory roof curb must be installed
prior to unit installation. The roof curb must be square
and level to ensure proper condensate drainage. See
Figure 2 (page 6) . Please follow all instructions
provided with the kit.
• Secure roof curb or frame to roof using acceptable
mechanical methods per local codes. NOTE: Make sure
the two supports beneath the unit have been removed.
IMPORTANT NOTES TO INSTALLER
• When setting the roof curb for installation, routing and
securement of the gas heat exchanger condensate
drain line must be determined and installed prior to
setting the unit on the curb. It is recommended to drill
a 1.00”-1.25” diameter hole through the roof below
the rectangular opening located in outer close off curb
panel (G) of Nordyne offered curbs, approximately 15”
in from the short side of curb and 1”-2” in from the long
side of curb. If drilling a hole is not an option, routing the
condensate drain hose over to the duct passage opening
with enough slope is acceptable as long as drain line is
secured to curb and duct, ensuring no kinks or traps can
form between the collector box drain or interior of the
building. Leave a minimum of 24” drain line extending
out the top of roof curb front close off panel (G) for
passage through unit bottom and connection to unit
drain when unit is being set. See unit or Condensate/
Vent Drain Kit (P/N-922485) instructions for completion
of the drain connection.
• It is recommended no non-serviceable connections are
introduced in the drain line between unit drain connection
and an accessible area within the building interior.