Variable Chilled Water Supply Temperature

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Hi everyone,

I have created a customized hourly report for chillers to understand the
supply water temperature of screw chillers. It was observed that the
leaving temperature is varying from 44?F to 65?F which is quite high.

This seems very strange as the set-point cooling control is fixed and the
set point cooling temperature is 44?F under the chilled water loop. Also I
have considered the loop set point range as zero (0). As per the inputs
entered under the chilled water loop, the supply chilled water temperature
should be near around 44?F.

Can anyone guide me on this, why the supply water temperature of the
chiller is varying and how I can fix this?

Thanks in advance.

Nitin Harjai's picture
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Joined: 2015-09-23
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You indicated Loop > Controls > Cooling > Setpoint Control > Fixed . Id also clear out any Reset Schedule Inputs if there in there. Leftover/ghost inputs can mess with us sometimes.

Also check Loops > Operation > Loop Operation > Standby/Demand/Snap. This has caused issues for us in the past when not set properly
Might also run hourly report to see if there are any demands on loop from coils for cooling when the temperature has floated up. If no demands, then CHW temperature may not matter.

Thanks,
DARIC ADAIR PE, CEM, BEMP
Mechanical Engineer, Energy Analyst

HENDERSON ENGINEERS
daric.adair at hendersonengineers.com

LICENSED IN KS

HENDERSON PROUD SINCE 1970 | JUST GETTING STARTED.

Daric Adair's picture
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Joined: 2017-10-21
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