Halton Rex RXP – Chilled beam (CAV/VAV)

Overview

Compact fully flexible CAV/VAV chilled beam with 4-way air distribution for suspended ceilings. Ensures silent and pleasant room conditions even with higher cooling capacities.

Application area

• Cooling and ventilation in offices, hospital rooms, schools, and public spaces.
• Can be used in Halton’s demand-based ventilation systems.

Key features

• Active chilled beam with 4-way air distribution.
• Three product models with adjustable airflow using manual CAV or motorised VAV
  • Standard model with boost airflow control and pressure dependent operation
  • Flexible model with 0-100% airflow control and pressure dependent operation
  • Autonomic model with 0-100% airflow control and pressure independent operation
• Throw pattern expanded to corners, which ensures pleasant room conditions even with high cooling capacities.
• Model with Halton Workplace WRA, room automation system package

Halton chilled beams are certified by Eurovent Certita.

Link to Certificate

Operating principle

The primary supply air enters the plenum of the Halton Rex RXP chilled beam, from which it is diffused into the room through the nozzles and supply slots. The air jets from the nozzles induce ambient room air efficiently through the heat exchanger, where the air is cooled by means of the cool water circulating in the heat exchanger. The supply slots direct the air jets horizontally along the ceiling surface, which prevents the feeling of draught.

The blue arrows in Fig.1. show the supply air coming through the supply slots. The red arrows show the ambient room air going through the front panel and the heat exchanger.

Fig.1. Operating principle of the Halton Rex RXP chilled beam

Halton Air Quality (HAQ) control in Halton Rex RXP, standard model

Halton Air Quality (HAQ) boost airflow control is used for adjusting or controlling the rate of the additional supply airflow in a room space. In normal conditions, fresh supply air is provided through the nozzles. Whenever additional air is needed (boost/VAV function), the HAQ control opens and provides more air. VAV stands for Variable Air Volume.

The HAQ control can also be used as a Constant Air Volume (CAV) damper, that is, it can be used for adjusting the k-factor to achieve the correct airflow with a certain pressure level. This removes the need for changing or plugging the nozzles of the Halton Rex RXP chilled beam.

Fig.2. VAV function: Supply air from nozzles (normal mode)


Fig.3. VAV function with HAQ control: Supply air from nozzles and HAQ control (boost mode).


Fig.4. Adjustment of the manual actuator of HAQ control in Halton Rex RXP, Standard model


Fig.5. Electric actuator of HAQ control in Halton Rex RXP, Standard model

Halton Operation Mode Damper (OMD) in Halton Rex RXP, Flexible model

Halton Operation Mode Damper (OMD) fully flexible airflow control is used for manual supply airflow adjustment or for motorised Variable Air Volume (VAV) control of the supply airflow rate. The OMD control flexibly combines nozzle and HAQ airflow control providing full airflow flexibility with one nozzle configuration.

The OMD control can be used as a Constant Air Volume (CAV) damper, that is, it can be used for adjusting the k-factor to achieve the correct airflow with a certain pressure level. This removes the need for changing or plugging the nozzles of the Halton Rex RXP chilled beam.

When the OMD control is equipped with a motorised actuator, fully flexible VAV control is achieved. It allows different VAV modes with for instance minimum, normal and boost airflow settings.

Fig. 6. Adjustment of the manual actuator of OMD control in Halton Rex RXP, Flexible model

Fig. 7. Electric actuator of OMD control in Halton Rex RXP, Flexible model

Halton Operation Mode Damper (OMD) in Halton Rex RXP, Autonomic model

Halton Operation Mode Damper (OMD) fully flexible airflow control is used for manual supply airflow adjustment or for motorised Variable Air Volume (VAV) control of the supply airflow rate. The OMD control flexibly combines nozzle and HAQ airflow control providing full airflow flexibility with one nozzle configuration.

In Halton Rex RXP, Autonomic model, when the OMD control is equipped with a motorised actuator integrated with pressure measurement, fully flexible VAV control with pressure independent operation is achieved. It allows different VAV modes with for instance minimum, normal and boost airflow settings.

Fig. 8. Electric actuator integrated with pressure measurement of OMD control in Halton Rex RXP, Autonmic model

Velocity control in the occupied zone

Halton Rex RXP, Flexible and Autonomic models can be equipped with Halton Velocity Control (HVC). It is used for adjusting room air velocity conditions either when room layout is changed (e.g., in cases where the partition wall is located near the chilled beam) or when local, individual velocity conditions need to be altered. HVC adjustment has an impact on the induced room air flow through the heat exchanger, and therefore it either increases or decreases both the velocities in the occupied zone and the cooling/heating capacity of the chilled beam.

Fig. 9. HVC in position Normal

Fig. 10. HVC in position Throttle

There are HVC controls in all four sides of Halton Rex RXP chilled beam. The HVC is divided into two parts in the long sides of RXP-1200 chilled beam. This enables the adjustment of conditions in different parts of the occupied zone.

Key technical data

Features and options

Table 1. Halton Rex RXP, Standard model (RXP/S)

Table 2. Halton Rex RXP, Flexible model (RXP/F) and Autonomic model (RXP/A)

Fig.9. Duct connection: Spigot positions left, straight, right 

For more detailed information on the order code, see section Order code.

System package

Halton Workplace WRA room automation system package for Halton Rex RXP chilled beam, Standard model (RXP/S)

Halton Workplace WRA is part of the Halton Workplace solution offering.

Fig. 10: Halton Workplace WRA room automation controller integrated to Halton Rex RXP chilled beam

Halton Workplace WRA is a controller especially designed for controlling the automation system of office spaces and meeting rooms. It is used for controlling the ventilation airflow, room temperature, and indoor air quality.

The Halton Workplace WRA room automation package consists of a controller unit and optional components depending on customer needs: a wall panel and sensors for temperature, CO₂, occupancy, pressure, and condensation.

There are options available for the controller unit and wall panel, depending on the number of controls and sensors required. The Halton Workplace WRA room automation controller is always combined with other Halton products for adaptable and high-level indoor climate.

Application area

• Controlling the ventilation airflow, room temperature, and indoor air quality in office spaces and meeting rooms
• The Halton Workplace WRA room automation controller is an important part of the Halton Workplace system, controlling room units and airflow control dampers
• Overall Halton Workplace System includes:
  • Room air conditioning applications with Halton Workplace WRA room automation controller:
    • Active chilled beams
    • Exhaust units
    • VAV dampers
    • Active VAV diffusers
  • Halton Max MDC zone control dampers

Key features

• Factory-tested controller and wiring, easy to install
• Pre-installed project-specific parameters, quick to commission
• Several operating modes based on occupancy, thermal comfort, and indoor air quality
• Enables fully flexible layout solutions for changing needs in office environments
• Highly energy-efficient and reliable system operation

Operating principle

The Halton Workplace WRA room automation controller operates with Variable Air Volume (VAV) dampers and active chilled beams of the Halton Workplace system. These are used for adjusting the ventilation airflow, room temperature, and indoor air quality in office spaces.

Each room unit in an office space can have its own dedicated Halton Workplace WRA room automation controller, or a single controller can control multiple room units. The Halton Workplace WRA room automation controller can automatically adjust the system according to the indoor environment level preferred by users. Each room unit having its own dedicated controller brings maximum flexibility.

Room automation: Halton Rex RXP active chilled beams with HAQ control and PTS damper, controlled with Halton Workplace WRA room automation controllers

Fig. 11. Halton Rex RXP active chilled beams with HAQ control and PTS damper, controlled with Halton Workplace WRA room automation controllers in a double office room

Room automation description

In this configuration, two Halton Workplace WRA room automation controllers (type DXR2.E18-102A) control two Halton Rex RXP active chilled beams. Each chilled beam has heating and cooling valves, motorised Halton Air Quality (HAQ) control, as well as integrated CO₂, pressure, and condensation sensors. A Halton PTS single-blade damper is used for controlling the minimum operating mode. The system also includes an exhaust VAV damper, window switch control, external occupancy sensor and a wall panel (type QMX3.P37) with a temperature sensor and display. One Halton Workplace WRA room automation controller can individually control up to four terminal units, and there can be several Halton Workplace WRA room automation controllers in the room.

Design criteria for room automation

• Chilled beam has heating and cooling valves
• Chilled beam has motorised HAQ control
• Chilled beam has integrated CO₂, pressure, and condensation sensors
• External occupancy sensor
• Wall panel with temperature sensor and display
• Window switch control
• Optional PTS damper for controlling minimum airflow
• Exhaust airflow control

Schematic drawing

Fig. 12: Schematic drawing: Halton Rex RXP chilled beam (4-pipe) controlled with Halton Workplace WRA room automation controller

Equipment list

Fig. 13: Factory-installed Halton Workplace WRA room automation controller, type DXR2.E18-102A

Wiring diagram

For the wiring diagram of similar configuration, see the product page of Halton Workplace WRA room automation controller, section Installation information.

Components and order code examples for the system

• 2 x Active chilled beam: Halton Rex RXP
  RXP/C-1200-S2, TC=H, AQ=MO, CO=SW, ZT=N
• 1 x Exhaust unit: Halton AGC Exhaust grille + Halton PRL Plenum for grilles
  AGC/N-400-100 FS=CL, ME=A, FI=PN, CO=W, ZT=N+PRL/F-400-100-160
• 1 x VAV damper: Halton Max Ultra Circular (MUC) or Halton Max One Circular (MOC)
  MUC/G-160, MA=CS
• 2 x standby, shut-off damper: Halton PTS
  PTS/A-125, MA=CS, MO=B4, ZT=N
• 2 x standby, shut-off damper: Halton PTS
  PTS/A-125, MA=CS, MO=B4, ZT=N
• Automation package: 2 x Halton Workplace WRA room automation controller unit with related components
  WRA/RXP-E81-H3-EX4, WP=37, LC=NA, SE=CI, SW=NC, ST=IA, SL=OI, PM=P1, TC=H, CV=SP5, RV=NA, ZT=N

Note: For more information, see the product pages of the Halton Workplace WRA room automation controller

Cooling and heating water valve selection in Halton Workplace WRA room automation system package

Water valve selection is done in Halton Workplace WRA room automation system package. Water valve sizing depends on the number of secondary and primary chilled beam units that are controlled with single controller. One water valve is used to control the whole chilled beam group cooling or heating operated by one room controller. Water valve is sized for whole group when there are multiple chilled beams controlled with single controller unit. There can be one primary chilled beam with room controller and up to three secondary chilled beams. Water valve sizing for 1-4 chilled beams is shown below.

Quick selection

Airflow

Halton Rex RXP, standard model

Fig.14. Airflow ranges in l/s for Halton Rex RXP, standard model without HAQ/with HAQ closed with different static chamber pressure levels

Fig.15. Airflow ranges in m³/h for Halton Rex RXP, standard model without HAQ/with HAQ closed with different static chamber pressure levels

Fig. 16. Airflow ranges in l/s for Halton Rex RXP, standard model with HAQ @70 Pa total pressure 

Fig. 17. Airflow ranges in m³/h for Halton Rex RXP standard model with HAQ @70 Pa total pressure

Halton Rex RXP, Flexible and Autonomic models

Fig. 18. Airflow ranges in l/s for Halton Rex RXP, Flexible and Autonomic models @70 Pa total pressure

Fig. 19. Airflow ranges in m³/h for Halton Rex RXP,  Flexible and Autonomic models @70 Pa total pressure

Cooling capacity

Halton Rex RXP, Standard model

Halton Rex RXP, Flexible and Autonomic models

Structure and materials

Fig.20. Halton Rex RXP

Dimensions and weight

The dimensions are given in millimetres [mm].

Fig.21. Halton Rex RXP, Standard model dimensions (RXP/S-600)

Fig.22. Halton Rex RXP, Standard model dimensions (RXP/S-1200)

Fig.23. Halton Rex RXP, Standard. Flexible and Autonomic models dimensions (RXP/S,  RXP/F-1200 or RXP/A-1200)

Fig. 24. Halton Rex RXP, Flexible and Autonomic models dimensions (RXP/F-600 or RXP/A-600)

Weight

Halton Rex RXP, Standard model

* Nozzle type, see section Order code.

Halton Rex RXP, Flexible and Autonomic model

Specification

Active chilled beam with CAV/VAV airflow function and four-directional air distribution, used for cooling, heating, and ventilation in suspended ceilings, fulfilling the following requirements:

Function

• Three product models with adjustable airflow using manual CAV or motorised VAV actuators
  • Standard product model equipped with manual CAV or motorized (0…10 VDC) VAV actuators for boost airflow control and pressure dependent operation
  • Flexible product model equipped with manual CAV or motorised (0…10 VDC) VAV actuators for 0-100% airflow control and pressure dependent operation
  • Autonomic product model equipped with motorised (0…10 VDC or Modbus RTU/BACnet MSTP) VAV actuators for 0-100% airflow control and pressure independent operation
• Throw pattern expanded to corners automatically in higher airflow settings maintaining uniform supply air throw length.
• Flexible and Autonomic product models can be equipped with Halton Velocity Control (HVC) for adjusting room air velocity conditions individually on all four directions.

Structure

• Integral recirculation air path through the perforated front panel.
• Front panel removable to allow general maintenance and cleaning.
• Front panel removable without special tools.
• Four-directional air distribution.
• Unit width 595 mm, height 220 mm.
• Inlet duct diameter 125 mm or 160 mm.
• Duct connection position changeable without special tools.
• Measurement tap to allow airflow measurement.
• Pipework’s maximum operating pressure 1.0 MPa.

Materials

• Plenum, frame, and front panel manufactured from galvanised steel.
• All visible parts white, painted in RAL 9003, 20% gloss.
• All pipes manufactured from copper.
• Water connection pipes have a wall thickness of 0.9–1.0 mm.
• All pipe joints soldered.
• All pipe joints pressure-tested at the factory.
• Heat exchanger fins manufactured from aluminium.

Packaging and identification

• The product is protected by a removable plastic coating.
• The duct connection and pipe ends remain sealed during transport.
• The product is identified by a serial number printed on labels attached both to the product and the cardboard box.

Installation

When planning the orientation of the Halton Rex RXP chilled beam, the location of the supply air and water circuit connections must be taken into account. The supply air spigot can be at either side of the unit or at the same end with the water connections. The location can be easily changed on site, if needed.

The location of the actuator of the HAQ control (optional) must also be taken into account to ensure access to the airflow adjustment/actuator. The actuator is located in the middle of the left side of the unit. Similar way the location of the service hatch of the OMD control (manual or motorized models) must also be taken into account to ensure access to the airflow adjustment/actuator. See the details in section Operating principle.

The Halton Rex RXP chilled beam can be attached directly to the ceiling surface (H = 220 mm/225 mm standard/flexible model) or suspended using threaded drop rods (8 mm). The brackets for ceiling installation are located at the sides of the unit.

Fig. 25. Installation points of Halton Rex RXP 1200, Standard, Flexible and autonomic models. The location of the actuator in  Halton Rex RXP 1200, Standard model

Fig. 26. Installation points and the location of actuator of Halton Rex RXP 600, Standard model

Fig. 27. Installation points and the location of actuator of Halton Rex RXP 600, Flexible and Autonomic models model

It is recommended that the main pipelines of the cooling and heating water circuits are installed above the level of the heat exchanger to enable venting of the pipework.

The maximum operating pressure for chilled/hot water pipework is 1.0 MPa.

Commissioning

Adjustment of the cooling capacity

The recommended cooling water mass flow rate is 0.02–0.10 kg/s, resulting in a temperature rise of 1–4°C in the heat exchanger. To avoid condensation, the recommended minimum inlet water temperature of the heat exchanger is 14–16°C.

Adjustment of the heating capacity

The recommended heating water mass flow rate is 0.01–0.04 kg/s, resulting in a temperature drop of 5–15°C in the heat exchanger. The maximum inlet water temperature of the heat exchanger is 35°C.

Balancing and control of water flow rates

The water mass flow rates of the Halton Rex RXP chilled beam are balanced with adjustment valves installed on the outlet side of the cooling water loops. The cooling capacity of the Halton Rex RXP chilled beam is controlled by regulating the water mass flow rate.

Adjustment of the supply airflow rate

With a Halton Rex RXP chilled beam standard model (RXP/S) that does not have the Halton Air Quality (HAQ) control, the airflow depends on the chamber pressure and the selected nozzle. With the HAQ control included, also the position of the HAQ control must be taken into account. The k factors are given in the table below.

With a Halton Rex RXP chilled beam Flexible model (RXP/F) the position of the OMD control must be taken into account according to the table below.

The chamber pressure (RXP/S) or the OMD pressure (RXP/F) can be measured from a measurement tap under
the front panel.

The total airflow rate is calculated using the formula below.

where

• q_v          Airflow rate in l/s or m³/h
• Δp_m      Measured pressure [Pa]
• k             The k factor given as a function of mounting and diameter (see tables below)

Halton Rex RXP, Standard model (M=S)

*Nozzle types: C = Medium, D = Large, E = Extra large

Table 1. The k factors with different HAQ control positions for Halton Rex RXP, Standard model in l/s

*Nozzle types: C = Medium, D = Large, E = Extra large

Table 2. The k factors with different HAQ control positions for Halton Rex RXP, Standard model in m³/h

Halton Rex RXP, Flexible model (M=F)

Table 3. The k factors with different OMD control positions for Halton Rex RXP, Flexible model in l/s

Table 4. The k factors with different OMD control positions for Halton Rex RXP, Flexible model in m³/h

Halton Rex RXP, Autonomic model (M=A)

Table 5. The k factors with different OMD control positions for Halton Rex RXP, Autonomic model in l/s

Table 6. The k factors with different OMD control positions for Halton Rex RXP, Autonomic model in m³/h

Example 1:
The measured static chamber pressure is 70 Pa for RXP/S-E-600, and the position of the HAQ control is 3. The total airflow rate is 4.12*√(70) ≈ 34.3 l/s.

Example 2:
The OMD pressure measured from the measurement tap in RXP/F-F-600 S3 is 75 Pa. RXP/F-F-600 S3 is equipped with the manual actuator. The positions of the manual actuator can be moved with the metal rod shown in Fig. 24. The measured distance to the tip of metal rod is 40 mm. For calculating the total airflow rate, the k-value is taken from Table 4 (measured distance rounded to closest value in table), and calculated with the equation 0.82*√75 ≈ 7 l/s.

Fig. 28. Adjustment of the manual actuator in Halton Rex RXP, Flexible model

Order code

RXP/M-S-L-E; SP-TC-CT-CN-VC-CO-ZT

Order code example

RXP/S-E-1200-S2, SP=N, TC=C, CT=S, CN=NA, VC=N, CO=SW, ZT=N