We reserve the right to make changes without prior notice
42
6.4.2.6 Combined management of heating devices
If the unit is provided with multiple heating devices, such as a heat pump with a hot water coil, the controller
can control these heating devices individually or in combined operation.
Combined management of multiple heating devices is implemented by superimposing the activation
differentials of the devices, keeping the winter setpoint as reference. The figure below shows an example of
superimposed operation of heat pump compressors and 2 steps of electric heaters.
6.4.3 Ambient air humidity regulation
The controller can control air dehumidification and humidification in cases when an ambient humidity probe is
fitted. Humidity regulation is proportional and its setpoint and differential are set by the controller.
6.4.3.1 Air dehumidification
Air dehumidification is a function normally required in summer, in other words when the unit is running in
cooling mode.
If dehumidification is required, the controller overrides compressor activation even if the air temperature has
achieved the preset setpoint.
The number of compressors required for dehumidification must be set in the Manufacturer branch.
When compressor override causes the temperature to drop below the setpoint, and to prevent over cooling of
the air, the controller starts the heating devices (e.g. electric heaters or the hot water coil), where fitted, to
warm the air and to keep the desired temperature in the room.
The humidity controller is ON/OFF type, meaning that the compressors enabled for the dehumidification cycle
(Cdh) are started when the humidity value reaches the setpoint (SpUR) plus the neutral zone (ZNUR) and the
humidity differential (DUR). On the other hand, they are disabled when the humidity value drops below the
setpoint.
In cases where cooling and dehumidification are required simultaneously, the controller activates the highest
between the number of cooling and dehumidification compressors in order to meet the greatest demand.
The controller keeps the enabled compressors active even after the temperature reaches the stored setpoint.
However, if the temperature drops below the setpoint, the controller enables the heating devices according to
the offset and differential parameters referred to the summer setting, and not to the winter setting, as is
normally the case with heating. When the value resulting from the subtraction of the setpoint and 85% of the
differential summer band is achieved, the hot water valve and the compressors enabled for the
dehumidification cycle are stopped. Compressor overriding for dehumidification is started up again as soon as
the air temperature reaches the summer setpoint minus 15% of the summer band.