Heat Exchanger & Domestic Hot Water Storage Tank
In the front is a commercial heat exchanger. Behind the commercial heat exchanger is a domestic hot water storage tank.
The supply water from the city is directed through the heat exchanger where it is heated to a set point temperature. This is usually 120 to 130 degrees Fahrenheit. 180 degree water from the boilers run through tubes inside the heat exchanger while the cold water runs through the inside of the heat exchanger in separate channels outside the tubes where the hot boiler water is. The water is heated and then delivered to the community where it used for showers and washing dishes and other hot water uses.
Before the city water supply enters the heat exchanger the city water supply is diverted through a commercial hot water boiler economizer so that the colder city water supply is preheated to a temperature greater than 55 degrees F. which is the city water temperature supplied from the city water source. The economizer or pre-heater uses boiler flue gases to preheat the domestic water supplied to the heat exchanger for heating to the comfortable temperatures. After water makes its journey through all that it is stored in the domestic hot water storage tank you see behind the heat exchanger.