Water-cooled and air cooled lamp fixtures are continuing to grow in popularity especially in hot climates. Lamps run cooler and can be moved closer to plants. Water-cooled bulbs are difficult for thermal imaging equipment to detect (fawkin feds) Air cooled fixtures are inexpensive to operate and easy to set up. The plastic shield around the bulb also lowers light output by as much as ten percent.
By using a cooled lamp marijuana growers will decrease heat by 80 percent with a properly set up watter cooled bulb. The water and outer jacket account for a 10 percent lumens loss. Growers make up for the loss by moving the bulbs closer to the weed plants. On an average day, a 1000 watt bulb uses about 95 gallons to keep cool, if the water runs to waste. To re-circulate the water requires a big, big reservoir. The water in the reservoir must also be re-cooled. Reservoir coolers can cost $1000 upwards. Cooling the reservoir can also solve many of your heat related problems when living in a hot climate.