... , 150W,250W,400W Compact design Low noise Dynamic Compact Semiconductor Fan Heater, Industrial Electric Air Heater, CSL 028, 150W,250W,400WCompact ... upper protective grille at 20°C (68°F) ambient temperatureAxial fan, ball bearingair flow, free flow: CS 028: 13.8m³/ ... use within an enclosure in accordance with UL508A Compact Semiconductor Fan Heater, Industrial Electric Air Heater, CSL 028, 150W,250W, ...