Cooling coils are a device manufactured using a bundle of tubes. Usually, cooling coils are manufactured using metals that are good at conducting heat including copper and aluminum. The most common use of cooling coils is in air conditioning systems and refrigerators in our homes and industrial cooling.
In industrial applications, cooling coils are used for exchanging heat. Coldwater or refrigerant is passed through the cooling coil and the coils are connected with the external source of air or gas which helps to dissipate heat from the application. Cooling coils come in different shapes that include loops, lines, and circular according to the requirement of the application. To increase the heat transfer rate cooling coils are attached to the metal fins.
In addition to keeping the application cool, cooling coils are also used to keep control of the humidity level within an application.
How they work
To understand the function of cooling coils, let’s take an example of an air conditioning system in our home. Air conditioning systems use two types of coils, condenser coils, and evaporator coils. Evaporator is fixed in the unit which is kept inside our home and condenser is fixed in the unit which is kept outside the home. The refrigerant moves inside the closed circuit formed by the condenser and evaporator. The compressor and the expansion valve are the other two components used in this mechanism. The refrigerant works as a heat transfer medium. The function of the evaporator coil is to cool the air inside the home and the function of the condenser is to dissipate this heat outside the home. The cold refrigerant gas, which is passing through the evaporator coil, absorbs the heat from the air surrounding the evaporator coil and as a result, the temperature of the refrigerant in the evaporator coil raises and the temperature of the air surrounding the evaporator coil comes down. The blower throws this cool air into home. The hot refrigerant moves out of the evaporator coil and enters the compressor which is kept in the unit kept outside the home. The compressor applies pressure to the hot refrigerant gas, which further raises the temperature of the refrigerant gas. Then the hot refrigerant gas enters the condenser. The temperature of the refrigerant gas which enters the condenser is much higher than the temperature of the air surrounding the condenser. With the help of the large fan, the heat from the hot refrigerant gas inside the condenser is dissipated in the surrounding air. This process cools the refrigerant which changes its state to the liquid. Then the cold refrigerant liquid passes through the expansion valve, which changes its state to the gas. This cold gas is again enters the evaporator coil. The whole process repeats again and again and as a result, the temperature inside the home comes down.
It is important to understand that to make heat transfer possible, the temperature of the refrigerant inside the evaporator coil is less than the temperature of the air outside the evaporator coil, and the temperature of the refrigerant gas which enters the condenser is higher than the temperature of the air surrounding condenser.
Maintenance of cooling coils
Since cooling coils are manufactured using metal tubes, they need to be checked for leakages regularly. The surface of the metal tubes must be cleaned regularly because dust can degrade its performance.