Which type of metering device is commonly used for cooling applications?

The thermostatic expansion valve is commonly used in cooling applications because it plays a crucial role in regulating the flow of refrigerant into the evaporator coil. This device adjusts the amount of refrigerant based on the cooling load, ensuring that the system operates efficiently and maintains the desired temperature. It responds to varying conditions by modulating refrigerant flow, which allows for better control of the cooling process and enhances overall system performance.

In contrast, a capillary tube is a simpler metering device that lacks the ability to dynamically adjust refrigerant flow in response to load changes, making it less effective in systems where precise temperature control is needed. A filter drier, while important for removing moisture and contaminants from the refrigerant, does not regulate flow and is not a metering device. Lastly, the evaporator fan, although essential for circulating air over the evaporator coil to promote heat exchange, is not involved in refrigerant flow management, which is the primary function of a metering device.