Maximum Yield USA January 2017 | Page 72

CONTROL YOUR GROW In an open-air exchange room, can-style exhaust fans and other cooling and ventilation equipment can be triggered by thermostat controllers capable of determining day or night and programming unique settings for each. For example, it is likely that less air exchange will be required at night due to decreased transpiration, and thus, decreased need for fresh CO2. Night temps will also be lower, so fans won’t be needed to remove heat as often. A night program on a thermostat controller might be set to turn on exhaust fans at 10 degrees cooler than a daytime setting. Another consideration while ventilating a non-sealed indoor room is to filter the incoming air in order to prevent dust and pests. If odor is of concern, the internal and outgoing air can be scrubbed with a cylinder-shaped carbon filter. The filter would ideally be placed up high where hot air is moving by default, and the exhaust fan would be used inline with ducting, pulling air through the carbon filter and across the light reflectors, removing the heat and odors. If an internal air scrubber is needed for additional odor control, use an additional carbon filter running with a can-style fan placed on top, which creates a loop in the room that absorbs the volatile organic compounds (VOCs) or odor-causing molecules and prevents smells from seeping out of the garden. “ Lighting technology continues to evolve exponentially and, therefore, serious indoor cultivators should upgrade their lighting systems periodically.” 70 Maximum Yield USA  |  January 2017