Category
HVAC Room Controllers HLS 44
Control temperature and ventilation room by room with Produal HLS 44 room controllers.
An HVAC room controller lets occupants adjust their own comfort within limits while the BMS keeps overall control, for fan coils, VAV boxes, radiators and chilled beams. The Produal HLS 44 connects over Modbus RTU on an isolated RS-485 bus, with a setpoint of 18 to 26 °C and ±3 °C user adjustment.
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Selection guide
HVAC Room Controllers HLS 44 Guide
How an HLS 44 room controller works
It reads the room's own Pt1000 or built-in sensor, compares it against a setpoint the occupant can nudge within limits, and drives the room's actuator, whether a 0 to 10 V or PWM thermal valve, or an EC fan directly, to keep the space at that temperature. Everything is reported back to the BMS over Modbus RTU, so facilities staff can see and, if needed, override the room from a central point.
How to choose an HLS 44 variant
- Base model: the HLS 44 covers individual room temperature and VAV control, setpoint 18 to 26 °C (default 21 °C) with ±3 °C user adjustment, day and night modes and frost protection.
- Ventilation demand: choose the HLS 44-CO2 when the room needs demand-controlled ventilation; it adds a built-in CO2 sensor, typically ±40 ppm plus 3% accuracy.
- Actuator type: choose the HLS 44-SE for 0 to 10 V or PWM actuators and direct 0 to 10 V EC fan speed control, or 3-speed fan control through an FCRY 3 relay module.
- Power: all versions run on 24 VAC/DC; a DC supply limits outputs to 0 to 10 V, while an AC supply is needed for full PWM (triac) actuator functionality.
- Application: fan coils, VAV boxes, radiators and chilled beams in offices, hotel rooms, meeting rooms and hospital wards all suit the HLS 44 family.
For zones needing BACnet, two rooms per device, or wider I/O, see Proxima control units.
FAQ
Common questions
Can occupants change the room temperature setpoint?
Yes, within plus or minus 3 °C of the base setpoint, and the BMS can limit that adjustment range further if needed. The default setpoint is 21 °C, adjustable from 18 to 26 °C overall, with day and night modes and frost protection built in.
Can the HLS 44 control a 3-speed fan?
The HLS 44-SE variant can, either with a direct 0 to 10 V signal to an EC fan or, for a conventional 3-speed fan, through an FCRY 3 relay module. The base HLS 44 does not include this fan speed output.
How does the HLS 44 connect to the BMS?
Over Modbus RTU, on a galvanically isolated RS-485 bus, which keeps the controller's low-voltage bus electrically separated from other devices on the same network. All three HLS 44 variants use the same protocol and wiring approach.
Which HLS 44 variant includes a CO2 sensor?
The HLS 44-CO2, which adds a built-in CO2 sensor with typical accuracy of plus or minus 40 ppm and 3% of reading to the standard HLS 44 room controller, for demand-controlled ventilation in meeting rooms or classrooms.
Does the HLS 44 need an AC or DC power supply?
It runs on 24 VAC or VDC, but a DC supply limits its outputs to 0 to 10 V only. If your actuators need PWM (triac) control, an AC supply is required, so confirm the actuator type before specifying the supply.
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