The core is to calculate the required heat dissipation and reserve a margin based on the total heat generation of internal cabinet equipment and the maximum temperature difference inside and outside the cabinet, so as to select a suitable model. Additionally, consider the protection level (IP55 or above recommended), installation method and power supply system (commonly -48VDC), and decide whether to add a heating function based on the environment. Remote monitoring (e.g., RS485 Modbus interface) and comprehensive alarm functions are crucial for unattended stations.