Cool Tube Reflectors are ideal, if you need light for your plants without the generation of too much heat. A cool tube reflector cools the air during the illumination. It gets directly integrated into the ventilation system. Most of the heat will be directly sucked off via the ventilation system to avoid a high heat emission into the room. 

Especially for the operation of CO2-systems, the use of air cooling reflectors is recommended. Furthermore, cool tube reflectors are also used in tight rooms, for example with very low ceilings. The cooler the air flow, the better is the cooling effect. 

Air cooled reflectors can be placed extremely close to the plants. Thereby the plant gets more light, which results in higher crops.
With a cool tube reflector with a 250 wattage, for example, you are able to get as close as 2 cm to the plant tips. The reflector with 
400 watts, can be placed with a minimal distance of 5 cm. For the use of a cool tube reflector, always consider that a ventilation system is required.