Daikin Navigator WWV, Installation, Operation And Maintenance Manual

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9 

IOM 1264-1 • NAVIGATOR

®

 MODEL WWV CHILLERS

Heat Exchanger Water Piping 

Figure 3: Typical Piping, Shell and Tube Evaporator    

Be sure that water inlet and outlet connections match certified 

drawings and nozzle markings.

Field installed water piping to the chiller 

must

 include:

•  air vents at the high points.
•  a cleanable water strainer upstream of the evaporator 

and condenser inlet connections.

• 

a flow proving device for both the evaporator and 

condenser to prevent freeze up. Flow switches, thermal 

dispersion switches, or Delta-P switches can be used. 

Note that thermal dispersion flow switches are factory 

installed as standard. Additional flow switches can be 

used only if they are connected in series with the ones 

already provided. 

• 

sufficient shutoff valves to allow vessel isolation. The 

chiller must be capable of draining the water from the 

evaporator or condenser without draining the complete system.

•  matching mechanical connections. All evaporators and 

condensers have OGS-type grooved water connections 

(adhering to Standard AWWA C606) or optional flange 

connections. PVC piping should not be used. 

It is recommended

 that field installed water piping to the chiller 

include:

•  temperature sensors at the inlet and outlet connections of 

both vessels.

•  water pressure gauge connection taps and gauges at the 

inlet and outlet connections of both vessels for measuring 

water pressure drop.

 CAUTION

When common piping is used for both building heating and 

cooling modes, care must be taken to provide that water 

flowing through the evaporator cannot exceed 110°F. Water 

this hot can damage controls or cause the relief valve to 

discharge refrigerant.

Piping must be supported to eliminate weight and strain on 

the fittings and connections. Chilled water piping must be 

adequately insulated.

System Water Volume

All chilled water systems need adequate time to recognize a 

load change, respond to that load change and stabilize, without 

undesirable short cycling of the compressors or loss of control. 

In air conditioning systems, the potential for short cycling 

usually exists when the building load falls below the minimum 

chiller plant capacity or on close-coupled systems with very 

small water volumes. Some of the things the designer should 

consider when looking at water volume are the minimum 

cooling load, the minimum chiller plant capacity during the low 

load period and the desired cycle time for the compressors.
A storage tank may have to be added to the system to reach 

the recommended system volume. Refer to AG 31-003 for 

method of calculating “Minimum Chilled Water Volume”.
The water quality provided by the owner/occupant/operator/

user to a chiller system should minimize corrosion, scale 

buildup, erosion, and biological growth for optimum efficiency 

of HVAC equipment without creating a hazard to operating 

personnel or the environment. Strainers must be used to 

protect the chiller systems from water-borne debris. Daikin will 

RELIEF

3/8” PIPE PLUG

DRAIN

WELDED PIPE CONNECTIONS ARE NOT ALLOWED 

BETWEEN THE STRAINER AND EVAPORATOR DUE TO THE 

CHANCE OF SLAG ENTERING THE EVAPORATOR

FLOW

SWITCH

GATE

VALVE

FLOW

FLOW

OUTLET

BALANCING

VALVE

VIBRATION

ELIMINATORS

WATER

STRAINER

VALVED

PRESSURE

GAUGE

INLET

TEMP . 

SENSOR 

WELLS

GATE

VALVE

Note: ASME certification will be revoked if welding is performed on a vessel    

            shell or tube sheet.