AAON RK Series - Manual (Page 5)

5
GENERAL INFORMATION
The units are designed as self-contained heating,
cooling or combination units using refrigerant, chilled
water, natural or propane gas, electric resistance,
steam or hot water as shown on the unit rating plate.
This AAONAIRE® unit has been equipped with an
energy recovery heatwheel. This booklet is furnished
to assure the energy recovery feature will be properly
setup to perform in accordance with the job
specifications for your particular application.
The AAONAIRE® heatwheel option is designed to
recover energy that would normally be lost through the
ventilation required by today's codes and standards for
comfort and health. The benefits of energy recovery
are significant in that 35 to 40 percent of the unit
heating and cooling capacity can be achieved by
collecting this otherwise lost energy from the exhaust
air and returning this energy to the building. The cost
of removing humidity in the summer is also greatly
reduced by the use of the desiccant coating on the
energy wheel.
The Energy Recovery Cassette consists of a frame,
wheel, wheel drive system and energy transfer
segments. Segments are removable for cleaning or
replacement. The segments rotate through counter
flowing exhaust and outdoor air supply streams where
they transfer heat and/or water vapor from the warm,
moist air stream to the cooler and/or drier air stream.
This energy recovery process can reduce cooling
design loads by up to 4 tons per 1000 CFM of outdoor
air ventilation while also reducing heating demand and
humidification requirements. Operating savings,
reduced demand charges and first cost equipment
savings provide a rapid payback to the building owner.
The initial set-up and servicing of the heatwheel is very
important to maintain proper operating efficiency and
building occupant comfort.
Normal maintenance requires periodic inspection of
filters, the cassette wheel, drive belts, air seals, wheel
drive motor and its electrical connections.
Wiring diagrams are provided with each motor. When
wired according to wiring diagram, motor rotates
clockwise when viewed from the shaft/pulley side.
By carefully reviewing the information within this
manual and following the instructions, the risk of
improper operation and/or component damage will be
minimized.
It is important that periodic maintenance be performed
to help assure trouble free operation. Should
equipment failure occur, contact a qualified service
organization with qualified, experienced HVAC
technicians to properly diagnose and repair this
equipment.
INITIAL MECHANICAL CHECK & SETUP
Outdoor units equipped with outside air intake will
have an outside air hood. The outside air hood must
be opened prior to unit operation.
Remove shipping screws from each side of the hood in
the “closed” position. Lift hood to the “open” position,
seal flange, and secure with sheet metal screws.
Outdoor air intake adjustments should be made
according to building ventilation, or local code
requirements.
After the unit installation is complete, open the
cassette access door and determine that the energy
wheel rotates freely when turned by hand. Apply
power and observe that the wheel rotates at
approximately 30 RPM. If the wheel does not rotate
when power is applied, it may be necessary to readjust
the "diameter air seals".
AIR SEAL ADJUSTMENTS
Pile type air seals across both sides of the energy
wheel diameter are factory adjusted to provide close
clearance between the air seal and wheel. Racking of
the unit or cassette during installation, and / or
mounting of the unit on a non level support or in other
than the factory orientation can change seal
clearances. Tight seals will prevent rotation.
WHEEL-TO-AIRSEAL CLEARANCE
To check wheel-to-seal clearance; first disconnect
power to the unit. In some units the heatwheel
assembly can be pulled out from the cabinet to view
the airseals. On larger units, the heatwheel may be
accessible inside the walk-in cabinet.
A business card or two pieces of paper can be used as
a feeler gauge, (typically each .004" thick) by placing it
between the face of the wheel and the pile seal.
Using the paper, determine if a loose slip fit exist
between the pile seal and wheel when the wheel is
rotated by hand.
To adjust air seal clearance, loosen all seal plate
retaining screws holding the separate seal retaining