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Automatic " Quick Cool Down"
Configure the Automatic "Quick Cool Down" function for the chilled water reset to enable the optimization program to
balance comfort with energy savings. When in automatic cool down, the chilled water optimization reset overrides its
operation and drops the supply temperature under any one of the 5 following conditions:
The building is too warm and the incoming cooling requests rise above threshold
1
When this happens, the optimization program is overridden and the chilled water temperature resets downward by a
predetermined adjustable rate until the building cools down and no longer needs cooling. Input your preferred
threshold number of requests, that are needed before cool down occurs, and delay.
The chilled water return temperature gets too warm
2
The chilled water return temperature can act as an indicator of the facility warming up and exceeding occupant
comfort. Input your preferred high chilled water return temperature trip point that is needed before cool down occurs,
and delay.
The temperature difference across the evaporator gets too cold
3
Like Automatic Pause, the chiller could stay on longer if the load across the chiller remains high enough for it to
continue to run. If the temperature difference drops below the pause threshold, then you may want to actually lower the
chilled water supply temperature to increase the load. Dropping the chilled water supply temperature raises the
temperature difference and encourages chiller stability. Input your preferred low temperature trip point and delay.
NOTE This low temperature trip point should be below the pause trip point since the pause is the first step in
preventing excessive cycling. If the temperature drops below the pause trip point, then lowering the temperature would
be the second step.
The building relative humidity rises above a threshold (user-configurable)
4
Like Automatic Pause, this is a response to rising humidity levels. The Automatic Pause is the first step and, if the
humidity levels continue to rise, the second step is lowering the chilled water supply temperature. The setpoint
continues to drop each response interval until the relative humidity conditions drop to an acceptable level.
The chilled water temperature setpoint rises above a predefined high limit
5
This is another measure to prevent high humidity conditions, especially when you have chilled beams and the dewpoint
is a problem. Enter the high chilled water supply setpoint limit and the setpoint drops if the limit is exceeded.
IF the "Remote Quick Cool Down" BBV receives a binary ON signal
6
This is for those systems which, for any reason, need to cool down the supply temperature. It is activated by a remote
BACnet binary write signal.
During automatic cool down, the temperature drops immediately by the cool down temperature increment (which you define
in Quick Cool Down Incremental drop, Section 3 - Manual Overrides of Chilled Water Resets), and then the program cools
down by the same amount each Response Period.
In conditions above, you may select to cool down more quickly, as an "Emergency Cool Down", rather than the "Quick Cool
Down" settings in Section 3 Manual Overrides of Chilled Water Reset - and other Settings. If so, you may configure
"Emergency Cool Down Incremental Drop" settings in this section.
Chilled Water System Optimizer v2
Installation and Start-up Guide
Appendix B: The Chilled Water System Optimizer Commissioning view of the Properties page
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