Low Temperature Grow Light - The Cool Tube from Hydroponics Group
Channel: Hydroponicstoday
Date: 04/05/2013

http://www.hydroponicsgroup.com/products/grow-lights/cool-tube-with-intercooler-4/  The Hydroponics Group proprietary Cool Tube with 400 and 600 watt metal halide and sodium vapor grow bulbs offers an abundance of light for vegetation and flowering cycles while keeping temperatures within 4 degrees of the room's ambient temperature.  This means you get the benefit of metal halide and sodium vapor lighting that run at cooler temperatures than CFL or LED lighting.