What is a metering device's function in an HVAC system?

A metering device in an HVAC system plays a crucial role in controlling the flow of refrigerant throughout the system. Its primary function is to restrict the flow of refrigerant from the high-pressure side to the low-pressure side. By doing so, it creates a pressure drop that causes the refrigerant to expand and cool as it enters the evaporator coil. This cooling effect is essential for absorbing heat from the indoor environment, thereby providing effective air conditioning.

Moreover, the metering device ensures that the refrigerant is delivered at the appropriate rate to match the evaporator's requirements, optimizing the overall efficiency of the HVAC system. This regulation of refrigerant flow helps in maintaining proper system operation and contributes to energy efficiency while preventing issues such as flooding or starving the evaporator.