Power supply datasheets provide derating curves that show how much the output power needs to be reduced for either a given increase in temperature or a reduction in airflow. Forced-air cooling has a significant effect and allows a supply to operate at full power in higher ambient temperatures. In general, forced-air cooling requirements will be expressed in cubic feet per minute (CFM) or linear feet per minute (LFM). For example, the derating curve of CUI’s VBM-360 shows that increasing the airflow to 10 CFM enables the enclosed version of this supply to operate at 100% of full load at an ambient temperature of 60°C. This compares to a derated output of 60% of full load when the same supply relies on just natural convection. Note also that the open-frame version of this supply only achieves 100% of full load output up to 50°C, illustrating the further effect that the mechanical design of a power supply has on thermal management.