Daikin WCT, Installation, Operation And Maintenance Manual, Page: 14 / 40

D-EIMWC01308-16EN - 14/40
Cooling Towers
Check the condenser water flow rate to be sure that it conforms to the system design. Some form of
temperature control is also required if an uncontrolled tower can supply water below about 65

F (18

C).
A tower bypass valve is recommended. Unless the system and the chiller unit are specifically designed
for condenser bypass or variable condenser flow, it is not recommended, since low condenser flow rates
can cause unstable operation and excessive tube fouling.
The condenser water pumps must cycle on and off with the unit. Controlling the pumps with the unit
MicroTech controller is an easy way to accomplish this and is highly recommended. See Figure 8, Field
Wiring Diagram on page 21 for wiring details.
The quality of the water to both the condenser and evaporator should be analyzed by a water treatment
specialist. If not available in-house, competent water treatment specialists can be contracted. Water
treatment is essential for continued efficient and reliable chiller operation. Chiller performance can be
degraded by poor water quality due to rust, sludge, corrosion, mineral deposits, sedimentation, organic
growth etc. Proper chiller performance can be maintained by corrective water treatment when and if
necessary, and periodic cleaning of tubes. If fouling or contaminants may become an issue then it may
be necessary to allow a larger fouling factor for the chiller provided, and/or specific construction
materials for the job site.
Thermal Insulation
Insulation of cold surfaces is required to prevent condensation. These surfaces include the evaporator,
economizer, evaporator water heads and nozzles, suction piping, motor housing, oil cooler refrigerant
supply and return, economizer gas line, expansion valve, piping between economizer and evaporator and
the motor drain line.
Optional factory installed insulation is available in ¾- inch (19 mm) and 1 ½-inch (38 mm) thickness. It
is UL recognized (File # E55475) ABS/PVC flexible foam with a skin. The K factor is 0.28 BTU/hr x

F x sq ft (W/m2 x

C) at 75°F (23.9

C). Sheet insulation is fitted and cemented in place forming a
vapor barrier and then painted with a resilient finish that resists cracking. Double insulation is available
as an option.
The insulation complies to, or has been tested in accordance, with the following:
ASTM-C-177 ASTM-C-534 Type 2 UL 94-5V
ASTM-D-1056-91-2C1 ASTM E 84 MEA 186-86-M Vol. N
CAN/ULC S102-M88
In the event insulation is to be field-installed, none of the cold surfaces identified above will be factory
insulated. Required field insulation is shown beginning on page 14. Approximate total square footage of
insulation surface required for individual packaged chillers is tabulated by evaporator code and can be
found below.
Table 1, Evaporator insulation Surface (approx.)
Note : Includes Shell, Tube Sheets and Tube Heads
Evaporator Code Insulation Area Sq. Ft. (m
2
)
E4824
840 (78)
E4826
915 (85)
E5424
935 (87)
E5426
1025 (95)