Once-Through Cooling

While once through cooling was once very common, only the smallest of cooling systems now use it. In these designs, groundwater or city water is brought into the condenser (say at 60°F), heated to about 95°F and then usually disposed of. But, look at how much water is being used! One ton of cooling would use over 41gallons of water an hour! This is why most areas of the country banned once-through cooling years ago for anything other than the smallest applications. However, there are certain situations where it could be a excellent way to preheat boiler feedwater or process water.