The enclosed with fan models have an operating temperature range of -40°C ~ +80°C and support a full 450 watts of continuous output power. At 115 VAC input, the 12 VDC model allows full power to +45°C and the 15 VDC model has the full 450 watts to +50°C with the 24, 36 and 48 VDC models delivering 450 watts up to +55°C before derating begins. In a more extreme +80°C ambient environment and with a 115 VAC input, the 12 VDC model still has 270 watts of output power, the 15 VDC has 290 watts, and the 24-48 VDC models have 320 watts of continuous output power capability.