7
• Allow minimum clearances from the enclosure for
fire protection, proper operation, and service access
(see unit clearances). These clearances must be
permanently maintained.
•
The combustion air inlet and flue outlet on the unit
must never be obstructed. If used, do not allow the
economizer/manual fresh air damper/ motorized fresh
air damper to become blocked by snow or debris. In
some climates or locations, it may be necessary to
elevate the unit to avoid these problems.
• When the unit is heating, the temperature of the return
air entering the unit must be a minimum of 55° F.
Ground Level Installations Only:
• When the unit is installed on the ground adjacent
to the building, a level concrete (or equal) base is
recommended. Prepare a base that is 3" larger than
the package unit footprint and a minimum of 3" thick.
•
The base should also be located where no runoff of
water from higher ground can collect in the unit.
Roof top Installations Only:
• To avoid possible property damage or personal injury,
the roof must have sufficient structural strength to
carry the weight of the unit(s) and snow or water
loads as required by local codes. Consult a structural
engineer to determine the weight capabilities of the
roof.
•
The unit may be installed directly on wood floors or on
Class A, Class B, or Class C roof covering material.
•
To avoid possible personal injury, a safe, flat surface
for service personnel should be provided.
• As indicated on the unit data plate, a minimum
clearance of 36" to any combustible material is
required on the furnace access side of the unit. All
combustible materials must be kept out of this area.
• This 36" clearance must also be maintained to
insure proper combustion air and flue gas flow. The
combustion air intake and furnace flue discharge must
not be blocked for any reason, including blockage by
snow.
•
Adequate clearances from the furnace flue discharge
to any adjacent public walkways, adjacent buildings,
building openings or openable windows must be
maintained in accordance with the latest edition of the
National Fuel Gas Code ANSI Z223.1/NFPA 54.
• Minimum horizontal clearance of 48" from the furnace
flue discharge to any electric meters, gas meters,
regulators and relief equipment is required.
Unit Precautions
• Do not stand or walk on the unit.
• Do not drill holes anywhere in panels or in the base
frame of the unit except where indicated. Unit access
panels provide structural support.
• Do not remove any access panels until unit has been
installed on roof curb or field supplied structure.
•
Do not roll unit across finished roof without prior
approval of owner or architect.
• Do not skid or slide on any surface as this may
damage unit base. The unit must be stored on a flat,
level surface. Protect the condenser coil because it is
easily damaged.
Roof Curb Installations Only:
Curb installations must comply with local codes and should
be done in accordance with the established guidelines of
the National Roofing Contractors Association.
Proper unit installation requires that the roof curb be firmly
and permanently attached to the roof structure. Check for
adequate fastening method prior to setting the unit on the
curb.
Full perimeter roof curbs are available from the factory
and are shipped unassembled. Field assembly, squaring,
leveling and mounting on the roof structure are the
responsibility of the installing contractor. All required
hardware necessary for the assembly of the sheet metal
curb is included in the curb accessory.
WARNING
To prevent possible equipment damage, property
damage, personal injury or death, the following
bullet points must be observed when installing
the unit.
•
Sufficient structural support must be determined prior
to locating and mounting the curb and package unit.
• Ductwork must be constructed using industry
guidelines. The duct work must be placed into the
roof curb before mounting the package unit. Our full
perimeter curbs include duct connection frames to be
assembled with the curb. Cantilevered type curbs are
not available from the factory.
•
Curb insulation, cant strips, flashing and general
roofing material are furnished by the contractor.
• The curbs must be supported on parallel sides by roof
members.
• The roof members must not penetrate supply and
return duct opening areas as damage to the unit might
occur.
NOTE: The unit and curb accessories are designed
to allow vertical duct installation before unit
placement. Duct installation after unit placement
is not recommended.
CAUTION
All curbs look similar. To avoid incorrect curb
positioning, check job plans carefully and
verify markings on curb assembly. Instructions
may vary in curb styles and supersedes
information shown.
