Greenhouse Automation - Fan Controller

The fan controller provides variable-speed control for three 120 VAC 4A fans. The circuit board and electrial fittings are housed in a commercial water-tight enclosure, shown in the pictures below.

Fan Controller enclosure, top removed	Fan Controller enclosure, bottom view

The fan controller enclosure is mounted at the top of a corner of the greenhouse (shown in the picture on the left below). As with the other controllers, the fan controller is provided with 12 V DC power and two communication wires through a connecting cable (shown entering from the left in the picture on the right below), and is also supplied with 120 VAC power (shown entering from the right center in the picture on the right below). The enclosure also has two electrical fittings to supply the variable power to the three fans.

Fan Controller mounting	Fan Controller cabling

One output of the fan controller was used to control an oscillating fan (shown in the picture on the left below) that circulates air in the greenhouse. In the case of this fan, the variable-speed feature was not used to control fan speed (the fan was turned fully on or fully off) because the speed of oscillation would also be affected. Instead, speed settings available on the fan itself were used to control fan speed. The other two outputs of the fan controller were used to control two exhaust fans (interior view shown in the picture in the center, exterior view shown in picture on the right below) positioned at the bottom of opposite diagonal corners of the greenhouse. In the case of these fans, the variable-speed feature was used to vary fan speed and control the amount of air drawn into the greenhouse in order to help regulate the temperature in the growing area.One output of the fan controller was used to control an oscillating fan (shown in the picture on the left below) that circulates air in the greenhouse. In the case of this fan, the variable-speed feature was not used to control fan speed (the fan was turned fully on or fully off) because the speed of oscillation would also be affected. Instead, speed settings available on the fan itself were used to control fan speed. The other two outputs of the fan controller were used to control two exhaust fans (interior view shown in the picture in the center, exterior view shown in picture on the right below) positioned at the bottom of opposite diagonal corners of the greenhouse. In the case of these fans, the variable-speed feature was used to vary fan speed and control the amount of air drawn into the greenhouse in order to help regulate the temperature in the growing area.

Oscillating fan	Exhaust fan, inside view	Exhaust fan, outside view

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This page last revised on 05/05/2018