CEMP-E
TI 811-12
18 August 1998
(b)
Space dry bulb temperature - one per zone.
(c)
Chiller supply water temperature.
(d)
Space relative humidity - one per zone (where required).
(2)
UMCS outputs to utility system. Chilled water supply temperature CPA - one per chiller.
b. Software I/O requirements. The software requirements are:
(1)
Program inputs.
(a)
Chilled water valve position.
(b)
High limit for space dry bulb temperature.
(c)
High chilled water operating temperature.
(d)
Low chilled water operating temperature.
(e)
High limit for space relative humidity.
(f)
Equipment constraints.
(2)
Program outputs. Chilled water supply temperature setpoint.
c. Application notes. The chilled water temperature reset program will affect any system requiring
chilled water.
11. CONDENSER WATER TEMPERATURE RESET PROGRAM. The energy required to operate
refrigeration systems is directly related to the temperature of the condenser water entering the machine.
Heat rejection systems are designed to produce a specified condenser water temperature such as 85F at
peak wet bulb temperatures. Automatic controls are provided at some sites to maintain a specified
temperature at conditions other than peak wet bulb temperatures. In order to optimize the performance of
refrigeration systems, condenser water temperature is reset downward when OA wet bulb temperature
will produce lower condenser water temperature. The reset schedule will incorporate the manufacturer's
requirements governing acceptable condenser water temperature range. Design requirements for this
applications program will be indicated by the letter X adjacent to the program listing on the appropriate
database table, as shown in Chapters 8 and 9.
a. Field hardware requirements. The hardware requirements are:
(1)
UMCS inputs from utility system.
(a)
Condenser water supply temperature - one per condenser.
(b)
OA dry bulb temperature.
(2) UMCS outputs to utility system. Condenser water supply temperature CPA - one per
condenser.
b. Software I/O requirements. The software requirements are:
(1)
Program inputs.
(a)
High condenser water operating temperature.
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