Halton Rex Expander (RXP) – Chilled beam

Compact 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.
• Adjustable airflow using manual CAV or motorised VAV, with the Halton Air Quality (HAQ) control.
• Throw pattern expanded to corners, which ensures pleasant room conditions even with high cooling capacities.
• Model with Halton Workplace WRA, room automation system package

The primary supply air enters the plenum of the Halton Rex Expander 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.

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

In figure Operating principle of the Halton Rex Expander chilled beam, the blue arrows 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.

Halton Air Quality (HAQ) control 

Halton Air Quality (HAQ) 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 Expander 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. Manual actuator of HAQ control

Fig.5. Electric actuator of HAQ control

Fig.1. Duct connection: Spigot positions left, straight, right 

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

Halton Workplace WRA room automation system package for Halton Rex Expander (RXP) chilled beam

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

Fig. 1: Halton Workplace WRA room automation controller integrated to Halton Rex Expander (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 Expander (RXP) active chilled beams with HAQ control and PTS damper, controlled with Halton Workplace WRA room automation controllers

Fig. 2: Halton Rex Expander (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 Expander (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. 13: Schematic drawing: Halton Rex Expander (RXP) chilled beam (4-pipe) controlled with Halton Workplace WRA room automation controller

Equipment list

Fig. 14: 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 Expander (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.

Airflow 

Fig.1. Airflow ranges for Halton Rex Expander without HAQ/with HAQ closed 

Fig.2. Airflow ranges for Halton Rex Expander with HAQ @60 Pa, 125 mm spigot 

Cooling capacity

Fig.1. Halton Rex Expander parts 

The dimensions are given in millimetres (mm).

Fig.1. Halton Rex Expander dimensions (RXP-600)

Fig.2. Halton Rex Expander dimensions (RXP-1200)

Fig.3.Halton Rex Expander dimensions (RXP-1200 with duct connection Ø 160 mm)

Weight:

The product must fulfil the following requirements:

• A CAV/VAV chilled beam with four-directional air distribution, used for cooling, heating, and ventilation.
• A chilled beam meant for suspended ceilings.

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 packed in a cardboard box.
• The product is identified by a serial number printed on labels attached both to the product and the cardboard box.

When planning the orientation of the Halton Rex Expander 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 actuator. The actuator is located in the middle of the left side of the unit.

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

Fig.1. Installation points of the RXP-1200 (RXP-600) chilled beam 

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

Adjustment of the supply airflow rate 

With a Halton Rex Expander chilled beam 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 chamber pressure can be measured from a measurement tap under the front panel.
The total airflow rate is calculated using the formula below.

Total airflow rate

where

q_v          Airflow rate [l/s] or [m³/h
Δp_m      Measured static chamber pressure [Pa]
k            Determined according to the table below [l/s]. If calculating m³/h, multiply by 3.6.

Example:
The measured static chamber pressure is 70 Pa for RXP/E-600, and the position of the HAQ control is 3. The total airflow rate is 4.1*√(70) ≈ 34.3 l/s.

RXP/S-L-E, TC-AQ-CO-ZT

S = Nozzle type
C     Medium
D     Large
E     Extra large

L = Length (mm)
600 or 1200

E = Duct connection
S2    Straight (Ø125)
R2    Right (Ø125)
L2     Left (Ø125)
S3     Straight (Ø160)
R3    Right (Ø160)
L3     Left (Ø160)

Other options and accessories

SP = System package 
N          No 
Y          Yes  

TC = Cooling / Heating functions (Coil type)
C        Cooling
H        Cooling and heating

AQ = Halton Air Quality (HAQ) control
NA     Not assigned (CAV)
MA     Manual (adjustable CAV)
MO     Motorised (VAV)

CO = Colour
SW    Signal white (RAL 9003)
W       Pure white (RAL 9010)
X        Special colour

ZT = Tailored product
N      No
Y      Yes (ETO)

 Sub products 

System package                        Halton Workplace Room Automation (WRA)
Room exhaust VAV damper     Halton Max One Circular (MOC)
Room exhaust VAV damper     Halton Max Ultra Circular (MUC) 

Order code example

RXP/E-1200-S2, SP=N, TC=C, AQ=NA, CO=SW, ZT=N