The Belimo CR24-B3 room controller offers an economical solution for individual temperature control in a single room. It is suitable for VAV applications and combined 2 and 4 pipe systems. It features five inputs and two outputs. The outputs can control one or more VAV controllers, heating via a 3-point signal, and change over operation.

The controller allows you to set the desired temperature and switch modes using the control wheel. The status indicator with an LED shows which mode is currently selected.

Energy Override

This is a feature of the controller's energy efficiency, where it will heat the room only to its protective level. This function is particularly suitable during periods when the room is not in use and does not need unnecessary heating or cooling, yet still ensures the safe preservation of plants, paintings, and others. The heating value is significantly reduced (15 °C), while the cooling value is greatly increased (40 °C).

Standby Function

This function is suitable for rooms that are used only occasionally or are temporarily unoccupied. The heating and cooling values are only slightly adjusted to reduce costs, but at the same time, there is no problem in quickly bringing the room temperature to the desired state.

Frost Protection

In the event of the room temperature dropping below 10 °C, frost protection is activated.

Change Over

The change over operation allows you to select an output common for both heating and cooling, or designate it exclusively for one option.

External Temperature Sensor

An external sensor can be connected to the ai1 input of the controller to measure the average room temperature in the ventilation duct. 

External Setpoint Adjustment

The ai2 input can be used for changing the temperature setpoint via an external 0...10 V signal. This function is used for summer/winter compensation.

Airflow During Heating

In heating mode, it allows increased airflow. This is required, for example, in heating with an air heater. The function also improves air quality when heating is on.

Ventilation

Allows the room to be ventilated with maximum airflow. Suitable especially for quick airing during long meetings, in hotel rooms, and others. During this function, room temperature control is not active, but frost protection still operates.

Boost

If necessary, it is possible to either heat or cool the room with maximum airflow. This function is particularly useful when the room needs to be quickly heated or cooled.

Cooling Ceilings

If the room temperature drops below the dew point, the corresponding output changes automatically. This is mainly used in rooms with cooling ceilings where there is a risk of water condensation.