Evaporator Coil for Heat Pumps & Air Conditioners
Evaporator Coil for Heat Pumps & Air Conditioners – the evaporator is responsible for absorbing heat into the coils and the refrigerant. The evaporator is an essential component of vapor compression refrigeration. This is usually done as result of passing air or water over the evaporator coil where a heat exchange process takes place. Heat leaves the air or water (whatever medium is used) and is absorbed into the coil and the liquid refrigerant. As more and more heat is absorbed by the evaporator coil and the refrigerant again changes state from a liquid to a refrigerant vapor. By the time the refrigerant leaves the evaporator coil the refrigerant should be all vapor and ready to be received again by the refrigeration compressor.
Evaporator Coil for Heat Pumps & Air Conditioners - Refrigerant Flow
The evaporator is typically inside the air handling unit or it can be installed in the duct work near the air handling unit. When the air handler blower turns on and the condenser is running refrigerant flows from the compressor through the condenser and then through the metering device. and into the evaporator.
Evaporator Coil for Heat Pumps & Air Conditioners - Changing State
The refrigerant changes state in the coils. In the evaporator coil the change of state is from a liquid to a vapor while in the condenser the change of state is from a vapor to a liquid. This is all necessary for the process of refrigeration to work properly. The typical evaporator coil is constructed of copper with aluminum fins surrounding the copper coils. The aluminum fins adds surface area to the copper coils and enhances the heat exchange rate making the coils more efficient. Although some manufacturers are switching to all aluminum coils in both the condenser and the air handler evaporator coil. For more on this you can read our article titles aluminum versus copper coils.