The Vari-Green^® HOA provides the hand/off/auto functionality of a motor starter and allows for easy integration into other building systems. Set fan speed at this control (hand mode), stop the fan (off mode), or have another control toggle the fan on/off (auto mode). Two auto modes are available. The first allows a user to set the fan speed on the control and turn the fan on/off remotely. The second, allows a user to turn the fan on remotely and pass a 0-10V signal from another control for a speed reference. 24V is also available for powering other controls.

The Vari-Green transformer provides a 24-volt power source from the existing line voltage at the fan to the motor and controls. It has two dry auxiliary contacts (one normally open and one normally closed) available to signal a motorized damper or interlock with other devices.

The remote dial or touch remote allows the user to manually adjust a fan’s speed from a remote location. These controls mount to a wall using a 2x4 junction box and are supplied with a wall cover plate. The 24VDC transformer, described above, is included with all orders. The Touch Remote includes a countdown timer to automatically turn the fan off after 10, 30, 60 or 90 minutes.

The two-speed control allows motor RPM (fan speed) to operate between two discreet speeds (A or B). There are two methods for switching between speeds:

• SPDT switch or relay connected to the dry contact input.
• Wet voltage (115-230VAC) applied to the digital input terminal

The two-speed control includes a 24VDC transformer and accepts an input voltage of 115/208-240V.

The Indoor Air Quality – Temperature / Humidity control monitors the temperature and/or relative humidity in a space. It will automatically adjust the ventilation rate to or from a space by increasing or decreasing the speed of the fan based on the desired set point.

The Indoor Air Quality – VOC control senses the level of Volatile Organic Compounds (VOCs) in a space and automatically adjusts the ventilation rate to the space by increasing or decreasing the speed of the fan based on the level of VOCs present. Ventilating based on the VOC concentration assures the space will not be over or under ventilated. Up to 10,000 unique VOCs exist, and Greenheck’s VOC sensor reacts to all of them.

The Constant Pressure control is quite versatile and can be used to monitor either the static pressure or velocity pressure in a system. The control will automatically adjust the fan speed to maintain a desired static pressure or velocity pressure (used for constant CFM) in the system. This control will reduce energy consumption not only by reducing the speed and the energy used by the fan, but will also reduce the amount of conditioned air that is exhausted.