What is the purpose of an expansion valve?

An expansion valve plays a crucial role in the refrigeration cycle, specifically in the process of regulating the flow of refrigerant between the high-pressure side and the low-pressure side of the system. Its primary function is to reduce the pressure of the refrigerant, which allows it to expand and, in turn, cool significantly as it moves into the evaporator coil.

By regulating the flow of refrigerant, the expansion valve ensures optimal operation of the system, allowing the refrigerant to absorb heat effectively as it evaporates in the evaporator. This careful management of refrigerant pressure and flow is essential for maintaining the efficiency and performance of HVAC systems, as it directly affects the temperature control and overall cooling capacity.

In contrast, increasing refrigerant pressure, filtering contaminants, or maintaining indoor air quality are functions associated with other components in an HVAC system, such as compressors for increasing pressure, filters for cleaning refrigerants, and air handling units for ensuring air quality. These functions are distinct and separate from the specific role of the expansion valve in regulating and reducing refrigerant pressure.