Access Configuration Manual

In some applications the load for heat/cool in the same building might vary (e.g. north vs. south side of the building). Zone control enables equalization of the indoor temperature in the entire building by controlling the temperature of up to three additional zones.

Zone control can also be used to partially or fully replace the building’s climate control system. The supply air temperature to the zone is adjusted in accordance to the room or to the extract air temperature.

Note! The zone controller may only run when the air handling unit’s supply air fan is running.

A zone controller is a temperature controller separate from the air handling unit’s temperature regulation. This means it has zone specific settings and sensors, e.g. zone supply air temperature, but functions similarly to the air handling unit’s temperature control:

Zone temperature control mode: Supply air

The controller is regulating the supply air temperature toward "Setpoint supply air".

Each temperature zone has its own 1/2 Neutral zone settings.

Zone temperature control mode: Room cascade

Room (zone) temperature is kept stable while the supply air temperature varies. Temperature changes in the room is monitored and the setpoint for the supply air controller is calculated.

Zone temperature control mode: Extract air cascade

Zone extract temperature is kept stable while supply air temperature varies. Temperature changes of the extract air is monitored and the setpoint for the supply air controller is calculated.

Zones can be fully independent or be slaved by the main supply air controller of the AHU. The interlocked zones are only allowed to add heating (or cooling) if the main supply temperature controller is in heating (cooling) mode:

Zones can be heated by water or electric heaters and cooled by water or DX coolers. Each of the heaters and coolers are controlled through individual PID controller.

The configuration steps for the heaters and coolers are similar to configuring sequences (e.g. water heater, electric heater, water cooler, DX cooling).

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Last reviewed: 9/21/2021

Access version: 4.5-1-01 (2913)