Catalogue

10 RLC-PRC039B-EN
Application Considerations
Staggering the chiller set points is another control technique that works well for preferentially
loading Chiller 1. If the cooling load is less than 50 percent of the system capacity, Chiller 1 would
be able to satisfy the entire call for cooling. As system loads increase, Chiller 2 is started to meet
any portion of the load that Chiller 1 can not meet.
Typical Water Piping
All building water piping must be flushed prior to making the final connections to the chiller.To
reduce heat loss and prevent condensation, insulation should be installed. Expansion tanks are
also usually required so that chilled water volume changes can be accommodated.
Short Water Loops
The proper location of the temperature control sensor is in the supply (outlet) water connection or
pipe.This location allows the building to act as a buffer and assures a slowly changing return water
temperature. If there is not a sufficient volume of water in the system to provide an adequate buffer,
temperature control can be lost, resulting in erratic system operation and excessive compressor
cycling. A short water loop has the same effect as attempting to control from the building return
water.Typically, a two minute water loop is sufficient to prevent problems.Therefore, as a
guideline, ensure the volume of water in the evaporator loop equals or exceeds two times the
evaporator flow rate in gallons per minute. For a rapidly changing load profile, the amount of
volume should be increased.To prevent the effect of a short water loop, the following items should
be given careful consideration: A storage tank or larger header pipe to increase the volume of water
in the system and, therefore, reduce the rate of change of the return water temperature.
ApplicationsTypes
• Comfort cooling.
• Industrial process cooling.
• Ice/thermal storage.
• Low temperature process cooling.
Figure 3. Typical series chiller arrangement