Common features - EasyIO - LIT-12014127 - EASYIO-FW-VAV - FV-VAV - 1.0

EasyIO FW-VAV Application Note

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Mode control

Use the central variable air volume (VAV) air handling unit (AHU) or roof top unit (RTU) controller occupancy schedule to place the system temperature setpoints in the occupied or unoccupied mode of operation. Before scheduled occupied periods occur, the central VAV AHU or RTU starts automatically and provides morning warm up or cooling. The VAVs precondition the space and achieve the occupied setpoint at the scheduled occupied time. A morning warm up command from the central VAV AHU or RTU forces the VAV to reach the maximum flow and enables the central VAV AHU or RTU to precondition the space when the space requires heating.

Use the standby mode for periods of temporary vacancy. You can determine the standby temperature setpoints. The standby mode can be triggered by a local hardwired occupancy motion sensor or through the network motion detection command from smart lighting control systems, communicating motion sensors, card access systems, a global load shed command, or other energy management system commands. During unoccupied and standby periods, the fan cycles to fulfill the heating or cooling demands to reach the unoccupied and standby temperature setpoints.

The system automatically reverts to the default mode of operation when the power restores after a power failure.

Occupant schedule override control

By default, the schedule is always set to occupied. In the unoccupied mode, use the room temperature sensor wall override button to set the system in the occupied mode of operation for 120 minutes. The central VAV AHU or RTU monitors the VAVs and returns to the occupied mode of operation anytime you set a VAV in the override mode.

Demand controlled ventilation

In an occupied room, a local wall mounted CO2 sensor switches the primary air flow setpoint from the minimum air flow setpoint to the maximum air flow setpoint, if a rise of measured CO2 concentration above the adjustable CO2 setpoint occurs. The central VAV AHU or RTU monitors the associated VAVs and increases the percentage of AHU supplied outside air in response to the VAV CO2 concentration. The opposite occurs, if a drop of measured CO2 concentration occurs.

Wall sensor module

Use the wall module setpoint adjustment knob and the bypass push button on the wall temperature sensor module to adjust the local temperature or to set the unoccupied mode. You can change the local heating and cooling setpoints with the local wall module setpoint adjustment and set the allowable offset.

Your adjustments do not affect the setpoints in use when the room is in the unoccupied or standby modes.