Overview of …
2.9 Exploiting Low Ambient Temperature for Water Chilling
This part of the Energy Efficiency Manual presents energy conservation measures that exploit low outside air temperature to reduce your cooling energy cost. When the outside air temperature is lower than the inside temperature, you can use the low outside temperature to aid in cooling the water in a chilled water system.
This inexpensive cooling is enhanced by the evaporative cooling effect of the system cooling towers. This principle can reduce the load on the chiller or even to allow the chiller to be turned off. You will learn the techniques for exploiting low outside air temperature, including “free cooling”, “waterside economizers”, direct cooling from cooling tower water, the “strainer cycle”, and more unusual methods.