AAON M2-036 - Manual (Page 70)

70
Air Balancing
High performance systems commonly have
complex air distribution and fan systems.
Unqualified personnel should not attempt to
adjust fan operation or air circulation, as all
systems have unique operating
characteristics. Professional air balance
specialists should be employed to establish
actual operating conditions and to configure
the air delivery system for optimal
performance.
Water Balancing
A hydronic specialist with a complete
working knowledge of water systems,
controls, and operation must be employed to
properly balance the entire system.
Unqualified personnel should not attempt to
manipulate temperatures, pressures, or flow
rates, as all systems have unique operating
characteristics and improper balancing can
result in undesirable noises and operation.
Controls
A variety of controls and electrical
accessories may be provided with the
equipment.
Identify the controls on each unit by
consulting appropriate submittal and order
documents, and operate according to the
control manufacturer’s instructions. If you
cannot locate installation, operation, or
maintenance information for the specific
controls, then contact your sales
representative, or the control manufacturer,
for assistance.
Operation
Immediately following building occupancy,
the air conditioning system requires a
maintenance schedule to assure continued
successful operation. A maintenance
program similar to the example given below
should be scheduled for routine maintenance
of this equipment in order to provide
continued efficient and reliable operation for
the owner.
Adjusting Refrigerant Charge
Adjusting the charge of a system in the field
must be based on determination of liquid
sub-cooling and evaporator superheat. On a
system with a TXV liquid sub-cooling is
more representative of the charge than
evaporator superheat but both measurements
must be taken.
Before Charging
Unit being charged must be at or near full
load conditions before adjusting the charge.
Units equipped with hot gas reheat must be
charged with the hot gas reheat valves
closed while the unit is in cooling mode to
get the proper charge. After charging, unit
should be operated in reheat
(dehumidification) mode to check for
correct operation.
After adding or removing charge the system
must be allowed to stabilize, typically 10-15
minutes, before making any other
adjustments.
The type of unit and options determine the
ranges for liquid sub-cooling and evaporator
superheat. Refer to the tables below when
determining the proper sub-cooling.
The Clean Air Act of 1990 bans the
intentional venting of refrigerant
(CFC’s and HCFC’s) as of July 1,
1992. Approved methods of recovery,
recycling or reclaiming must be
followed. Fines and/or incarceration
may be levied for non-compliance.
CAUTION