Central Environment Controller

Figure 15: Environmental Controller. Source: Scott Sanford

Figure 15: Environmental Controller. Source: Scott Sanford

A central environmental controller (Figure 15) has many advantages over having individual controllers on each heater, fan and louver. First, it prevents heaters and fans from competing with each other because the same temperature sensor is used for controlling all equipment. Next, a central controller usually will have a smaller temperature differential between turning on and off a device and for maintaining a set point, which results in more precise control. Third, a central controller will generally have a time clock, so differential temperatures (DIF) between day and night can be automatically changed. If the controller allows a grower to take advantage of DIF, it will save about five percent in energy costs.