“What is the best temperature for my water condenser?” I have encountered this question a number of times during my first weeks at Stromquist & Company.
It is common knowledge that lowering the cooling tower sump temperature set point increases a chillers efficiency. As we lower the cooling tower sump temperature the condenser becomes sub cooled.
Sub cooling can increase the chiller’s efficiency about 1% per degree of sub cooling. Increased chiller efficiency means energy savings.
It is important to remember that there is a limit to this type of energy savings.
For example, on Trane chillers efficiency improvement bottoms out at around a 75 degree set point.
Lowering the set point past 75 degrees results in an increase in power consumption from the tower fan and pumps without improving the chiller efficiency.
It is important to maintain accurate temperature settings with all chillers. Since my background is Trane, I will speak specifically about set points when using a Trane Chiller.
If the temperature is too low, within the 60 degree range, you risk the oil carrying over into the evaporator. If the temperature is too high, above 75 degrees, the chiller is consuming excess energy and increasing your monthly energy costs.
The correct temperature range for Trane Chillers is between 72 and 75 degrees. Trane chillers that operate within these dimensions are maximizing energy savings and minimizing the risk of oil carrying over into the evaporator. In conclusion, save on energy costs and the environment and check your chiller set points.
Using a good remote bulb temperature controller like the Johnson System 450 or the Honeywell T775 is another important thing to consider. If your temperature controller is not accurate or does not control properly then any possible energy savings will be negated. So make sure you have a quality remote bulb temperature control.
I will be blogging at controltrends.com so send your questions about chillers, motors, and variable frequency drives to me. My email address is firstname.lastname@example.org.Loom for your answers at Ask Tim.
Also, check out my chiller classes.