When to use Cooling Towers, Chiller and Pumping Stations
An Evaporative Water Tower is an energy efficient way to dissipate heat from your process. It is common for people to think a chiller is needed anytime something needs to be cooled but we should do the exercise to find out if an evaporative tower can do the job. The major question is this… Can your process be cooled by 85F water? If unsure, check with operating personnel or the equipment manufacturer of the process. If the answer is yes, then you’re on the road to an efficient way to cool your process. We say 85F, because on average summer days, a properly sized evaporative water tower can provide cooling water at 85F and even lower during cooler times of the year. A Cooling Tower Ton is 15,000 btu’s of energy vs 12,000 btu’s for a refrigerant ton, making a cooling tower more efficient. An evaporative water tower that is placed on the roof or elevated by legs and bracing provides a self-draining method into an indoor pump tank station where its water is then pumped to your processes providing year round operation. Thermal Products can work with you on the few technical pieces of data needed to size one properly.
A Chiller and it’s terminology in the industrial world denotes below ambient cooling with fluid temperatures mainly between 40F to 60F to your process. Many processes truly need these colder temperatures in which the heat removal through refrigeration is achieved. Most process applications can circulate process water through a loop in the building that is kept cool by a refrigerant chiller. This can be accomplished by installing either an “air cooled” or “water cooled” chiller. Air cooled chillers are most popular as they are easy to install and use. Both air & water cooled chillers can be placed outdoors or indoors. If placing an air cooled chiller indoors you need to be aware of the heat being rejected into your room. Thermal Products can assist you with that calculation.
Pump Tank Stations are an integral part of an evaporative water tower including tremendous thermal storage in the chiller process as well. Water has excellent characteristics to absorb heat quickly and then let it go. Incorporated in the use of an evaporative water tower means a large sum of 85F water in a 400 to 1500 gallon tank size retains this water while one or more pumps send this water to and from your process. It returns back warmer in many cases pre designed at 10 degrees higher. The same water mixes with a dedicated pump to the evaporative water tower, heat is removed in the tower or chiller, then is returned back to the tank.
While chillers, in most cases, have a smaller reserve of water on board, a pump tank station is used for “batch cooling”. You might have a process in which you only need to cool it a few times a day or maybe once a day such as quenching of parts. In this case, large amounts of cold water and a little chiller is the answer. Calculated properly a small chiller needs to only cool a large volume of water in a pump tank station. The chiller might, for example, have 4 hrs to cool a pump tank station, bring it down to 50F and await the next process. Once again, designed properly by Thermal Products this large volume of water might only raise 15 to 20 degrees higher, achievable for a chiller of moderate size.
