Chilled Beam Design Guide

Care for Indoor Air

Halton - Chilled Beam Design Guide

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Halton Chilled Beam Design Guide

Halton - Care for Indoor Air

Halton active chilled beams

create unique flexibility and good

indoor climate conditions during

the life cycvle of the building.

Active beam range includes

various outlook options for

applications ranging from offices

to hospital wardrooms.

Halton chilled beams adapt easily

to different interior designs of

the space. Installations vary from

exposed to concealed.

Passive chilled beams offer

various alternatives for

installation of the products for

renovations and new builds.

Active service beams integrate

various building services e.g.

luminaires, cabling, loud speakers,

sprinklers into a single unit.

Passive beams are also available

as service beam concept and

can integrate various serviced

into all-in-one solution.

Halton believes that high quality indoor air is the key to a healthier

and more productive life. We make this possible by delivering

leading indoor climate products and solutions, ranging from

commercial buildings to Marine and offshore environments

systems.

Halton broad chilled beam range offers solutions from active and

passive chilled beams to service beams. Halton chilled beams are

designed to provide advanced flexibility, comfort and competitive

life cycle costs. Here are some of our references world-wide.

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1. Chilled beam system 5

2. Target definition 6

3. Active chilled beams

3.1 Active chilled beam system 7

3.2 Chilled beam system design 8

3.3 System design strategies 9

3.4 Design elements 10

3.5 Chilled beam model selection 12

3.6 Adaptable chilled beam concepts 14

3.7 Chilled beam orientation and ventilation arrangements 22

3.8 Operation range specification 24

3.9 Pre-selection and selection 25

3.10 Indoor climate conditions’ design 27

3.11 Management of room conditions 28

3.13 Case study 31

4. Passive chilled beams

4.1 Passive chilled beam system 33

4.2 Chilled beam system design 34

4.3 Chilled beam model selection 35

4.4 Chilled beam orientation and ventilation arrangements 37

4.5 Operation range definition 39

4.6 Pre-selection and selection 40

4.7 Design of indoor climate conditions 42

4.8 Management of room conditions 43

5. Customised service beams

5.1 Luminaires and other integrated technical services 44

Contents – Chilled Beam Design Guide

Contents

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Chilled beam system

Halton’s chilled beam system is an air conditioning system for cooling, heating, and ventilation in spaces where good indoor climate and individual space control are appreciated.

A chilled beam system provides comfortable thermal conditions with quiet and energy-efficient operation.

The system can be realised with active or passive chilled beams, integrated multi-service chilled beams, or bulkhead-installed horizontal induction units.

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Chilled beam system

1. Chilled beam system

A chilled beam system provides excellent indoor climate conditions and cost-efficient life-cycle costs when realisation is managed properly from design to use of the building, covering:•Definitionoftargets•Systemdesign•Productselection•Roomcontrol•Ductworkandpipeworkdesign•Centralsystemsdesign•Eventualfreecooling/heatpumpapplications•Installationandcommissioning•Verificationofindoorclimateconditions

Flexibility throughout the lifetime of the buildingModern office buildings are designed to allow flexibility in use of the spaces to meet the requirements of even high churn rates (percentage of people moving in the building in one year).

The air conditioning system design can be carried out according to different strategies, for more limited to full flexibility:•AdaptableClimate concept•Traditionaldesign

Flexibility requirements can affect the design, logistics in transport and at the site, and the tasks required when layout or the use of space changes.

Halton chilled beamsHalton’s chilled beam range includes many different types and models:•Adaptableactivechilledbeams(CCC,CCE)for

suspended-ceiling and exposed installation•Activechilledbeamsforsuspended-ceilinginstallation

(CBC, CBD)•Activechilledbeamsforexposedinstallation(CBE,CBH)•Passivechilledbeamsforsuspended-ceilinginstallation

(CPA)

•Passivechilledbeamsforexposedsuspended-ceilinginstallation (CPT)

•Customisedactiveandpassiveservicebeamsforbothsuspended-ceiling and exposed installations

•Compact,bulkhead-installedinductionunitswithuni-directional horizontal air supply (CHH)

Applications for different chilled beam types

Active chilled beams. Active chilled beams are well suited to private and public office buildings, health care facilities,

and hotel buildings – in new construction as well as refurbishment projects. Active chilled beams are especially suitable for landscape and cell offices, patient care spaces, and hotel guest rooms.

Passive chilled beams. Passive chilled beams are used in the same applications as active chilled beams. There are, however, specific conditions favouring passive beam installations:•Applicationswhereventilationratesarerelativelyhigh–

e.g.,3…4l/s/m2 (10 … 15 m3/h/m2)•Refurbishmentprojectswheretheexistingventilation

system is to be preserved for the most part•Whereventilationisrealisedusingaseparatesystem–

e.g., an under-floor air distribution system

Chilled beams with uni-directional air supply. Units with uni-directional air supply are used in spaces where most of the ceiling is left free of room unit installations. The units can be standard chilled beam units designed for performance with uni-directional supply or units dedicated to uni-directional air supply in exposed or bulkhead installations.

Customised service beams. Active and passive customised service chilled beams are feasible for refurbishment projects in office and other public buildings.The benefits of multi-service chilled beam systems are:

•Effectiveinstallationoftechnicalservicesandgoodtotal

quality of installations due to off-site manufacturing and

short construction process

•Selectionofexposedorceiling-integratedbeamsonthe

basis of a feasibility study for the building by consulting

engineers

•Theabilitytocreateaestheticinteriorarchitectureeven

when floor height is low

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Target definition

2. Target definition

When the main targets for system operation and performance are set, the indoor climate target values are specified. One of the key goals in designing good indoor climate conditions is to adjust the cooling and heating capacity to the level that meets both optimal comfort and energy-efficiency targets.

Module sizing and flexibility requirements are also important factors influencing both design decisions and life cycle cost management for the building. It is also important to take into account national or international standards and building codes.

Indoor climate target levels according to CEN report 1752, on maximum values for thermal conditions.

Indoor climate factor Classification

Unit A B C

Operating temperature Winter °C 22+-1 22+-2 22+-3

Operating temperature Summer °C 24,5+-1 24,5+-1,5 24,5+-2,5

Vertical temperature gradient 0,1 m / 1,1 m °C 2 3 4

Mean velocity Winter m/s 0,15 0,18 0,21

Mean velocity Summer m/s 0,18 0,22 0,25

Sound pressure level Office rooms dB(A) 30 35 40

Sound pressure level Landscape offices dB(A) 35 40 45

Ventilation rate Office rooms l/s m2 2 1,4 0,8

Ventilation rate Landscape offices l/s m2 1,7 1,2 0,7

Design assumptions Occupancy:

Cooling load:

office rooms 0,1 person/m2, landscape offices 0,07 person/m2

50W/m2

Indoor climate design conditions:•Thermalconditionsaccordingtonationalor international standards or classifications •Roomairorambienttemperature •Roomairmeanvelocityordraughtrate(DR) •Internalsurfacetemperaturesandradiant asymmetry•Airqualitycriteriaaccordingtonationalor international standards or classifications. Air quality is often indicated with: •Outdoorairflowratelevel •CO2- concentrations•Soundlevelrequirement(NRorLpA)•Typicalspaces • Roomandmoduledimensions • Usageandoccupancylevel • Windowandwalltype,solarshading

Life cycle costs:•Targetsysteminvestmentcostlevel(€/m2)•Energy-efficiencytargets'levelscanbeexpressed as specific level of consumption of heating, air conditioning and electric power (fan power). The building shall be classified according to these consumptionlevels.(EnergyEfficiencyofBuildings Directive2002/91/EC)

•Maintenanceleveltargetsindicate: •Predictedserviceintervals •Theirlabourdemand •Accessibilityofservicepoints •Needtoreplaceparts/replacementinterval (valve, filter, motor etc.)

Flexibility for change:•Flexibilityrequirementscanbecharacterisedwith the required tasks when layout or the use of space changes: •Needforoffice/meetingroomchanges •Needtorelocateinternalwalls •Needforinstallation/reconnectionofterminal units or control units • Adjustmentofairflowrates • Adjustmentofwaterflowrates • Otheradjustments(e.g.personalrequirements)

Order delivery chain:•Targetsfororderdeliveryindicatetheversatilityof the terminal unit in terms of their models, sizes and operation parameters.

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Active Chilled Beams

3. Active chilled beams

3.1 Active chilled beam system Thechilledbeamsystemisanair/watersystemforhigh-temperature cooling and low-temperature heating that utilises the excellent heat transfer properties of water and provides a good indoor climate energy-efficiently.Typically, a chilled beam system is realised as a dedicated outdoor air system with sufficient airflow rates to ensure good indoor air quality.

Eitherthesystememploysafour-pipesystemoraseparate perimeter heating system is used.

Operation of the system Chilled beam systems are designed to use the dry cooling principle, operating in conditions where condensation is prevented by control applications.Chilled water can be produced by a dedicated chiller or a common chiller for air handling units with a separate, flow-water-temperature-controlled loop for chilled beams.Spacetemperaturecontrolisrealisedwithvariablewaterflow control.

VentilationVentilationusingactivechilledbeamsisanefficientmixing ventilation application that results in uniform air

quality.Supplyairisdischargedintothespacethroughlinear slots on either both sides or only one side of the chilled beam. Horizontal induction units have grilles for horizontal air supply.In demand-based ventilation applications, supply air flow can be increased by means of an integrated diffuser without affecting the heat transfer of the chilled beam.

CoolingActive chilled beams use the primary air to induce and recirculate the room air through the heat exchanger of the unit, resulting in high cooling capacities and excellent thermal conditions in the space. High-temperature cooling enables the use of free-cooling sources.

HeatingIntegration of heating into chilled beams is recommended when heating capacity is low enough (150…250W/m),andthelowheattransmissionthrough the windows prevents a down-draught under the window.

Low-temperatureheatingenablestheuseofvariouswaste-heat sources. Alternatively to water-circulated heating, electric heating can be integrated in chilled beam units.

Schematic diagram of a chilled beam system with both cooling and heating modes.

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Chilled beam system design

3.2 Chilled beam system design

A chilled beam system can be designed to fulfil requirements for sustainable, energy-efficient buildings that provide flexible use of space and a healthy and productive indoor climate. A chilled beam system can realise excellent indoor climate conditions in terms of thermal and acoustic properties throughout wide operation ranges and in many installation scenarios.

There are several choices to be made, each having an influence on the performance, investments, operation, and maintenance costs. The tables below present the range of variation of the main design characteristics and typical ranges of operation for a chilled beam system.

MAIN CHARACTERISTICS FOR CHILLED BEAM SYSTEM EVALUATION

Indoor climate conditions

AdaptableClimate concept Traditional concept

Good indoor climate conditions and efficient, practical operation with highly realistic design data for the building's whole life cycle.

Reservations for performance at extreme capacity levels with high safety margins.

Use of the space

Changes in use of the space and layout changes with marginal churn costs.

Optimised performance and unit cost for individual spaces with limitations in flexibility.Relatively high churn costs.

Efficiency of logistics

Effective design, installation, and commissioning processes; streamlined logistics with a uniform product range.

Need for individual product identification in design, ordering, delivery, and installation.

Life-cycle performance

Higher investments in more efficient chilled beams (greater difference), enabling savings in pipework central units and lower operation costs.

Lower investment costs for chilled beams and higher total investment and operating costs.

TYPICAL INPUT VALUES AND OPERATION RANGES

Room temperature, summer 23..25 °C

Room temperature, winter 20..22 °C

Supply air temperature 16..19 °C

Water inlet temperature, cooling 14…16 °C

Water inlet temperature, heating 35 … 40 °C

Target duct pressure level 70 …120 Pa

Target water flow rate 0.02…0.06 kg/s

Sound pressure level < 35 dB(A)

Outdoor air flow rate / floor area, offices 1.5 . . 2.5 l/s/m2 5 … 9 m3/h/m2

Outdoor air flow rate / floor area, meeting 1.5 … 4 l/s/m2 5 … 22 m3/h/m2

Outdoor air flow rate / effective unit length 5 ... 12 l/s/m 18 ... 44 m3/h/m

Additional air flow rate in meeting rooms 0 ... 45 l/s 0 ... 160 m3/h

Cooling capacity / floor area … 80 W/m2 …120 W/m2 *

Cooling capacity / effective unit length … 250 W/m … 400 W/m *

Heating capacity / floor area … 40 W/m2 … 60 W/m2 **

Heating capacity / effective unit length … 150 W/m … 250 W/m **

Note * It is reasonable to study the room air velocity conditions carefullyNote ** It is reasonable to study the thermal conditions carefully

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Systemdesignstrategies

When a chilled beam system is designed and chilled beams are selected, there are several angles to be considered.

The main target is to achieve excellent indoor climate conditions in spaces for the whole life cycle of the building,

even if there is a continuous need to make changes in the space usage or layout. Through designing and selecting

chilled beams according to an ‘adaptable’ strategy, this target can be achieved.

3.3Systemdesignstrategies

Adaptable system design

Adaptable system selection strategy provides benefits

to the facility owner, who can modify spaces more

quicklyandwithlesscostoverthefacility'slifetime.

ThermalconditionmanagementusingHaltonVelocity

Control(HVC)andairqualitycontrolusingHaltonAir

Quality (HAQ) provide continuously good indoor

climate conditions.

The design and installation teams can also benefit,

because changes in the use or size of spaces during

System design strategy

AdaptableClimate concept Traditional concept


Room air temperature 22 ± 2 °C 22 ± 2 °C

Room air velocity ... 0,25 m/s ... 0,25 (...0,30) m/s

Room air quality 1.5 ... 6 l/s,m2 1.5 ... 6 l/s,m2

Cooling capacity 60 ... 80 W/m2 60 ... 120 W/m2

Heating capacity 25 ... 40 W/m2 25 ... 60 W/m2

Adaptable performance

Halton Velocity Control in both throttle (1) and full (3) position.Adjustment of Halton Air Quality control.Constant flow water valves to adjust water flow rates.Constant-pressure air flow dampers in zones.

Adaptation by increasing the number of terminal units.

Chilled beam positioning

Always perpendicular to perimeter wall Either parallel or perpendicular to perimeter wall

Life cycle costs

Flexibility Full flexibility in layout and application changes: no installation work during changes.Churn costs of 8…12 €/m2.

Limited flexibility in layout and for changes in operation conditions.

Churn costs of 50…100 €/m2.

Product cost Some extra cost for flexibility in room units, zones, and central system.

Basic investment

Focus in product selection

Nozzle size, length, and effective length that are the same for all beamsHVC designed in normal position (2)HAQ to adjust air flow rateConstant-flow water valves.

Various nozzle sizes, lengths, and active lengthsWater flow control and adjustment valves and control units that are selected project- specifically and installed on site

Changes in space use in the design and installation process

No effect of changes in use or size of space on chilled beam selection

Reselection of chilled beams after the use or size of the space has changed

Commissioning Adjustment of chilled beams on site; no traditional commissioning needed

Manual balancing of air and water flow rates

Note: Typical design values. Check case by case.

the design and construction process do not influence

the beam selection.

Traditional system design

Designing and selecting chilled beams according to

‘traditional’ strategy allows indoor climate targets to

be met in the design conditions, but future changes in

use or layout may influence the products’

performance. This strategy results in a lower

investment cost, but changes during operation are

more costly.

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Design elements

A chilled beam system can realise excellent indoor climate conditions in terms of thermal, air quality, and acoustic

conditions within wide ranges of operation and in various installation cases. Operation should, however, be

designed with conditions in the occupied zone in all seasons (winter, summer, and intermediate season) taken into

account. For the best result, the following technical issues should be considered also.

3.4. Design elements

Ventilation and air diffusion using chilled beams

•Primaryairfromthenozzles(5…12l/s/m)induces

3 … 5 times the room air (depending on chilled

beam type and operating conditions).

•Atotalairflowrateof15…60l/s/misdischarged

fromone/twoslotsintothespace.

•Makesurethatairflowratescanberealisedatactual

chamber pressure levels.

•Minimumsupplychamberpressureis50…80Pato

ensure the correct supply air jet throw pattern.

•Checkthattherequiredthrottleforbalancingcanbe

achieved with the adjustment damper at an

acceptable sound level.

•Thesupplyairflowrateishighenoughtoremove

internal humidity loads.

•Thesupplyairjetshouldstayattachedtotheceiling

(Coanda effect) and not fall into the occupied zone.

•Thermalloadsintheoccupiedzonemayinfluence

the air jet direction and air distribution in the

occupied zone.

•Analysesupplyjetinteractionwithconvectiveflows

(e.g., caused by a cold or warm window surface) to

ensurethatitdoesn'tcreateadraughtrisk.When

already detached from the ceiling, jets of two

parallel chilled beams should not collide at a velocity

level that results in a draught.

•Theincreaseofairflowrateaccordingtodemand

should not have an effect on the cooling capacity.

Cooling using chilled beams

•Thethermalpropertiesoftheexternalwallsand

window construction should be appropriate.

•Therequiredcoolingcapacitiesshouldbemax.60…

80W/m2.

•Chilledbeamcapacities(250…350W/m)match

supplyairflowrates(5…12l/s/m)toprovidegood

air distribution and draught-free conditions in the

occupied zone.

•Waterflowratesandpressuredropsofchilled

beams are in line with chilled water pipe work

design and pumping cost target levels

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Design elements

Heating

Proper system operation cannot be achieved by

overdimensioning the heating capacities. In a modern

officebuilding,25…45W/m2 of floor area is typically

sufficient heating capacity.

•Theheatingcapacityofactivebeamsisdependent

on the primary airflow rate. This is why ventilation

shall be in operation when heating is required.

•Theheatingcapacityofactivebeamsistypically

150…250W/m,andtheinletwatertemperature

should be 35 … 45 °C to create sufficient mixing

between the supply air and room air.

•Bothwindowdraughtduetoradiationand

downward convective air movement during cold

seasons need to be eliminated.

•Anefficientcontrolsystemisused.Itis

recommended to have room air temperature

measurement integrated into a chilled beam, with

heating control based on the room air temperature

near the ceiling.

Operation case study: Chilled beams parallel to the

perimeter wall

In this type of installation, it is especially important to

have windows with adequate thermal properties for

avoiding excessively high room air velocities in

intermediate seasons.

This study was performed using computational fluid

dynamics (CFD) software. Air velocity is higher than

0.25m/sinthegreenareas.

1

2

3

The images present the room air velocities in the same space in three seasons: summer (1), spring (2) and winter (3).

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Active chilled beam model selection

The appropriate active chilled beam model is selected by taking into account the following factors:

•Architecturaldesign

•Preferredappearance

• Desireforexposedinstallationorasolution

integrated into a suspended ceiling

• Adaptationtotheceiling

• Positioningwithrespecttolightfittings

• Integrationoflightfittings

• Roomdesigngriddimensions

• Requirementsforflexibilityandeventualpartition

wall locations

•Coolingcapacityrequirements

•Buildingservicesintegratedintochilledbeams:

• Lightfittings,controls,sensors,detectors,andcabling

3.5. Active chilled beam model selection

Active chilled beams in suspended ceiling installation

Customised service beam.

Active chilled beam in wall installation.

Active chilled beam in exposed installation

Active chilled beam in suspended ceiling installation

Active chilled beam in bulkhead installation or in exposed installation.

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Active chilled beam model selection

Active chilled beams in exposed installation

Active chilled beams in wall installation

Customised service beams in exposed installation.

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Adaptable chilled beam concepts

Halton AdaptableClimate chilled beams offer unique flexibility from design through use. Their operation adapts easily

to changes in space usage, layout, or user requirements throughout the building’s life cycle. Good indoor climate

conditions are maintained with high energy-efficiency when an open-plan office is changed into cellular offices or

meeting rooms.

Chilled beams adapt thermal conditions to meet individual requirements, also in open-plan offices. Thus indoor

climate conditions are optimal in all usage situations throughout the building’s life cycle.

3.6.Adaptablechilledbeamconcepts

Benefits of the Halton adaptable chilled beams:

•Wideoperationrangesimplifiesdesignand

specification

•Goodthermalcomfortandindoorairquality

•Adjustableairflowrates

•Airvelocitymanagement

•Enhancedflexibility

•Freelocationofofficesandmeetingrooms

•Identicallookofunitsfordifferent

spaces

•Airflowcontrolthatcanbeinstalledas

needed

• Improvedlogistics

•Smoothorder-to-deliveryprocess

•Effectiveon-sitehandling

Features:

•Primaryairflowrateadjustmentof1.5to6l/s/m2

(5 … 20 m3/h/m2) in layout change from office room

to meeting room using Halton Air Quality control

(the air flow control does not affect the coil capacity,

and thus ‘over-chilling’ is avoided)

•Abilitytoachieveindividualdesiredvelocity

conditions in the occupied zone even when partition

walls are repositioned, by adapting the operation

usingHaltonVelocityControl

•Integratedcontrolandmax.flowlimitervalvesfor

cooling and heating capacity allowing reset without

influencing the water flows of other chilled beams

(optional)

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Primary airflow rate

Room Space type HVC position Nozzles qv2 HAQ qv2 Total qv2+ qv2 Total qv2+ qv2

left right l/s m3/h l/s m3/h l/s m3/h l/s/m2 m3/h/m2

1, 2, 3 Office 3 1 15 54 5 18 20 72 2 7.2

4 Meeting room 2 2 15 54 0...45 0...160 15...60 54...216 6 22

Halton Air Quality (HAQ) control

The air flow rate of the chilled beam is dependent on

•Effectivelength,Leff

•Chilledbeamchamberpressure,DPm

•Nozzlesize,Dnoz

•HaltonAirQualitycontrolunitadjustmentposition,

AQ

The chamber pressure is adjusted by changing the

position (a) of the air flow adjustment damper to

match available duct pressure at the room branch.

Four nozzle sizes are available, to enable attaining the

minimum supply air flow rate of the chilled beam at

the set pressure level in a typical room module.

There is no need to change or plug nozzles of the

chilled beam.

Halton Air Quality control allows increasing the chilled

beam airflow rate to meet the ventilation requirements

of spaces such as:

•officespaces:1.5…2.5l/s/m2

(5…9m3/h/m2)

•meetingrooms:4…6l/s/m2

(14 … 20 m3/h/m2)

Air flow control

The ventilation requirements of meeting and team

rooms vary greatly according to the occupancy level.

Demand-based ventilation control using, e.g., CO2

sensors, contributes to a highly energy-efficient

operation.

In addition to manual adjustment damper operation,

the HAQ damper can be equipped with an actuator

controlled by a room controller.

By integrating the air flow control into the chilled

beam unit, flexibility in use of the space is ensured.

Factors influencing an active chilled beam’s air flow rate.

Office rooms.

Meeting room.

When rooms with constant and variable airflow rates

are both served by the same distribution ductwork,

constant pressure conditions are needed to guarantee

the designed airflow rates.

Seethesection‘Constant-pressureductworkfor

efficiency’ for more information.

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Halton CCE with air quality control. The Halton Air

Quality control unit is on the top of the chilled beam,

supplying air upward. It is recommended to position

thebeamataminimumdistanceof600mmfromthe

wall and 100 mm from the ceiling.

The Halton Air Quality control unit is adjusted manually

or, alternatively, controlled by an actuator connected to

a room controller.

The HAQ unit can be retrofitted later as required. Also

the actuator can be mounted later, when changes in

room layout are implemented.

Total airflow rate of the chilled beam unit can be 5 to

25l/spermetre(18…90m3/h/m)whenequipped

with HAQ control.

The Halton Air Quality control unit does not increase

the length of the chilled beam.

Halton CCC with air quality control. In the Halton CCC

solution, the air quality control unit is at the opposite

end of the unit from the supply air connection. The

throw pattern of the air quality control unit is

bi-directional like that of the chilled beam.

The effective length of a chilled beam equipped with

air quality control unit (either manual or motorised

version)is600mmshorterthanthetotallength.The

look of the Halton CCC unit is identical to that of the

CBC chilled beam without HAQ unit.

Halton CCE with air quality control in a meeting room.


Halton CCC with air quality control in a meeting room.

16 17


Management of room conditions using

Halton Velocity Control (HVC)

HaltonVelocityControlisusedforadjustingroomair

velocity conditions either when room layout changes

(e.g., in cases where the partition wall is located near

the chilled beam) or when local, individual velocity

conditions need to be altered.

HaltonVelocityControldoesnotaffecttheprimary

supply air rate, but it does have a slight effect on the

cooling and heating capacities of the unit. The

capacities and velocities can be studied using the HIT

Design software.

It is recommended to design the chilled beam in the

‘normal’ position in order to allow both minimisation

(throttle) and maximisation (full) functions later in the

building’s life cycle.

HaltonVelocityControldampersaredividedinto

sections to enable the desired adjustment of velocity

conditions in different parts of the occupied zone.

Depending on the length of the beam, optimal lengths

ofHVCdampermodulesareusedasfollows:

CBC or CCC 300,500,and800mmCBEorCCE 300,600,and1100mm

Halton Velocity Control provides manual velocity adjustment on both sides of the chilled beam, with three positions: 1 = throttle position, 2 = normal position, and 3 = full position.

Adjustment of local velocity conditions is possible also in anopen-plan office with Halton Velocity Control.

Partition wall located close to the chilled beam. HaltonVelocity Control is adjusted to position 1 on one side and position 3 on the other.

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Halton Velocity Control is available for both exposed

and ceiling-installed chilled beams.

Halton Velocity Control in boost (3) and throttle (1) position in a Halton CCC chilled beam.

Halton Velocity Control in boost (3) and throttle (1) position in a Halton CCE chilled beam.

Case Study

FlexibilityforlayoutchangescanbedesignedinwiththeHVCandHAQconcepts.Chilledbeaminstallationadapts

to different room sizes and layout, providing required capacities and maintaining good comfort.

Primary airflow rate

Room Space type HVC position Nozzles qv2 HAQ qv2 Total qv2+ qv2 Total qv2+ qv2

left right l/s m3/h l/s m3/h l/s m3/h l/s/m2 m3/h/m2

1 Office 3 1 15 54 5 18 20 72 2 7.2

2 Office 3 3 15 54 15 54 30 108 2 7.2

3/Unit A Office 1 3 15 54 0 0 15 54 2 7.2

3/Unit B Office 3 1 15 54 0 0 15 54 2 7.2

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Constant-Pressure Air Distribution System

Constant-pressure ductwork for efficiencyIn traditional active chilled beam systems, the ductwork is a proportionally balanced constant-air-flow distribution system. However, there are reasons it is beneficial or otherwise reasonable to arrange the air flow management using active constant-pressure control dampers. Among these are that•chilledbeamswithpressure-dependentvariableflow

and constant flow are combined in the same ductwork sections and proper operation conditions are ensured

•frequentindividualairflowadjustmentsofchilledbeam units can be made without the need to balance the ductwork

•pressurecontroldampersallowzoneventilationoperation hours locally, contributing to energy conservation in office buildings where tenants’ office hours tend to differ, for example

Ductwork is divided into constant-pressure zones, allowing individual adjustment of the air flow rates of


Combined pressure-dependent variable flow and constant flow.

each room and continuous air flow control according to demand in meeting rooms.

Theductworkissizedusinglowvelocities(<6m/s),taking into account the predicted max. flow rate in order to minimise pressure losses within the zone and to maintain the desired air flow accuracy and meet cooling capacity requirements.

Ductwork balancing is not needed in constant-pressure duct systems when unitary airflow rates are adjusted (e.g.,forofficeroomspacechanges).Evenconstantairflow rates of office rooms can be integrated into the same ductwork as variable air flow rate control for meeting rooms.

Typically, the use of units that are similar (in length or nozzle type), along with individual adjustment of air flow rates, allows effective commissioning of the

system.

Fan pressure control Fan speed control is typically used when variable flow is required. In small and symmetric low-velocity ductwork, the need for zone dampers is not evident, but larger duct systems shall be divided into sections, where duct pressure is kept constant by means of zone dampers.

Adaptation to the variable operation conditions of a variable flow system can be realised with variable-

speed drives controlled by frequency converters. The

target is to maintain a duct pressure level that is as low as possible in order to save on fan power consumption.The pressure controller maintains a constant or optimised pressure level in the ductwork using a pressure sensor as feedback. The sensor measures the static pressure relative to prevailing pressure in the building.

20 21

The pressure sensor’s positioning is crucial for reliable

operation and fan power consumption.

Basic steps in positioning of the pressure sensor:

•Simulatetheductwork,anddeterminewhichindex

branch requires the highest pressure in the system

•Establishthelocationintheareaat2/3…3/4ofthe

distance between the terminal branch and the fan

•Studywhetherthesetpointpressurelevelwould

satisfy the demand in other branches

In cases where no index duct section can be

determined, multiple sensors should be used. The

sensor with the actual highest demand provides the

decisive feedback.


Constant-pressure zonesThe accuracy of realised airflow rates and cooling capacities requires duct pressure that varies only slightly in the ductwork. Acceptable deviation of the target pressure level at the room branch duct is 10 … 20 Pa in order to achieve airflow rate inaccuracy of less than 10%.

The practical zone size is dependent on:•Ventilationrates,inl/s/m2 (or m3/s/m2)•Diversityofoccupancyinmeetingrooms•Thespaceavailableforducts•Practicalductdimensions•Thespacelayoutplan•Operationhourpredictionforthespaces•Supplyandexhaustairarrangements

In cases where the zone size is too great, the following problems can occur:•Deviationfromtargetairflowratesandcooling/heating

capacities•Imbalancebetweensupplyandexhaustair•Eventualnoiseproblems

Zone dampers allow different operations hours when, e.g., working hours in an office building vary between sections of the building.

A rough estimate of a typical zone size (in m2), as presented in the table below, can be made on the basis of:•Ventilationratesinofficesandmeetingrooms,inl/sper

square metre•Reservationformeetingroomsthatarefullyoccupied

simultaneously, as a percentage of zone size•Max.circularductsizeofthebranchduct,inmm

Ideally, the pressure sensor in a constant-pressure zone is in the middle of the zone in the supply duct.It is beneficial to use the same duct size, in order to benefit the static-pressure regain in the main branch duct.

In the exhaust duct, the pressure sensor should be at the end of the main branch duct when under-pressure operation in the building is desired in a fully ducted exhaust system; otherwise, the sensor can be positioned in the middle of the ductwork.

With common exhaust tracksthe supply duct airflow rate,thesupply/exhaustairflowratebalancecanbemaintained accurately.

Ventilation rate Duct size D 400 Duct size D 500

Offices Meeting rooms Percentage of meeting rooms Percentage of meeting rooms

l/s m3 l/s m3 10% 30% 10% 30%

1 4 580 400 905 620

1.5 4 430 335 675 525

2 4 340 290 535 455

Zone size, in m2, estimated according to ventilation rates

20 21

Zone balance arrangements

When in the zone there are both units with constant

and units with variable flows, the exhaust is liable to

pressure deviations due to higher pressure losses in

the main branch duct and lack of regaining static

pressure. The air flow balance in spaces in meeting

rooms with variable flow can be realised in different

ways:

•Ductedexhaustusingavariableflowcontroldamper

•Continuousbalancedductedexhaustforconstant

flow

Transfer air via a grille to the corridor

Common zone exhaust tracking the variable

common supply airflow

•Transferairviaagrilletothecorridor

Common zone exhaust tracking the common

variable supply flow


Combination of ducted constant air flow exhaust and variable transfer to common exhaust.

Ducted variable air flow exhaust using variable air flow control damper.

Transfer air from spaces to common exhaust.

The common exhaust can take care of the air exhaust

of meeting rooms and eventual open office areas.

22 23

Chilled beam orientation and ventilation arrangements

3.7. Chilled beam orientation and ventilation arrangements

Chilled beams can be installed either perpendicularly or parallel to the perimeter wall. However, perpendicular

installation is recommended, as occupied zone velocities are thus lowest in all seasons. When chilled beams are

installed parallel to the wall, intermediate-season conditions (cold window surface and internal heat loads) should be

analysed. Otherwise, cool supply air with a cold window can easily create increased velocities under windows.

Perpendicular installation of chilled beams.

Parallel installation of chilled beams.

Selection of active chilled beam orientation

•Indoorclimateconditions

•Capacityperchilledbeamunit

•Residualvelocitiesforoccupiedzone

•Supplyairjetinteractionwithconvectiveflows

•Suitabilityforroommoduledimensions

•Suitabilityinviewoflightingfixturelocations

•Flexibilityforlayoutchanges

•Minimumrecommendeddistancebetweenparallel

beams

•Minimumrecommendeddistancebetweenchilled

beamandwall/ceiling

Side wall installation of chilled beams.

Bulkhead installation of horizontal induction units.

Side wall installations of chilled beams in a hotel guest room. Bulkhead installation of horizontal induction units in a hotel guest room

22 23

Chilled beam orientation and ventilation arrangements

Exposed installation above a work area: symmetric throw pattern.

Exposed installation close to wall:asymmetric throw pattern.

Selection of active chilled beam air arrangements

Active chilled beams should be positioned above work spaces to ensure comfortable velocity conditions. If the

chilled beam is positioned close to a wall, an asymmetrical throw pattern is recommended. Minimum installation

distances from walls and between parallel chilled beams are presented in the product data sheets.

Exhaustairunitshaveminorimportancetothesolution’soperation.

Suspended-ceiling installation above a work area: symmetric throw pattern.

Wall installation in hotel guest room.

Bulkhead installation in hotel guest room.

Bi-directional air supply

•Perpendiculartoexteriorwallinoffices(preferable),

above the work area

•Paralleltoexteriorwallaboveworkarea

•Perimeterinstallation,withuni-directionalsupply

•Corridorinstallation–limitedapplication,depending

on work area location and providing bi-directional

supply horizontally and downward

Uni-directional air supply

•Hotelguestrooms–preferablyabovebed(above

window as another option)

•Patientwardrooms–preferablyabovebed–either

along side walls or parallel to exterior walls

24 25

Operation range specification

3.8.Operationrangespecification

A chilled beam system’s operation range is determined on the basis of representative rooms. The selected rooms

are studied to determine cooling and heating loads via dynamic energy simulation software. After assessment of

load patterns in the representative rooms, chilled beam operation parameters are set. The design target values can

be verified by a full-scale mock-up or computational fluid dynamics (CFD) simulation.

Typical input values and operation ranges (extreme target values in brackets)

Room temperature for cooling 23..25 °C

Room temperature for heating 20..22 °C

Supply air temperature for cooling 16..19 °C

Supply air temperature for heating 16..19 °C

Water inlet temperature for cooling 14…16 °C

Water inlet temperature for heating 35…45 °C

Target duct pressure level for cooling 70 …120 Pa

Target water flow rate for cooling 0.02…0.10 kg/s

Target water flow rate for heating 0.01…0.04 kg/s

Outdoor air flow rate per unit floor area Offices: 1.5 … 2.5 l/s/m2, meeting rooms: 1.5 … 4 (6) l/s/m2

Outdoor air flow rate over effective length 5..12 l/s/m

Cooling capacity per unit floor area …80 (120) W/m2

Cooling capacity / beam’s effective length 250 (400) W/m

Heating capacity per unit floor area … 40 (60) W /m2

Heating capacity / beam’s effective length 150 (250) W/m

Comfort / PMV -0,5...+0,5

Draught rate (DR) <15%

Average room air velocity cooling 0,23 m/sheating 0,18 m/s

Definition of design conditions and operation

parameters

•Ventilationratesinspacesasrateperfloorarea,

l/s/m2

•Ventilationrateinspacesasrateperperson,

l/s/person

•Coolingcapacitydemandinspaces,inW/m2 and

actual breakdown of loads

•Heatingcapacitydemandinspaces,inW/m2 and


•Modelroomsandoperationalparameters

• Roomtemperature

• Supplyairtemperature

• Waterinlettemperature

• Targetductpressurelevel

• Targetwaterflowrate

• MaximumsoundpressurelevelVerification of target design values with full-scale mock-up and CFD simulation

24 25

Pre-selection and selection

Pre-selectionWith the help of quick-selection tables, pre-select the chilled beam (effective length and nozzle type), using the following parameters for the desired design conditions:•Indoorclimateconditions•Coolingcapacity•Airflowrate•Ductpressure•Minimumdistancebetweenparallelunits•Jetdetachmentpoint

3.9.Pre-selectionandselection

Make your design process more efficient. Halton’s design tools for the pre-selection and selection phase include

brochure data sheets with quick-selection charts and the Halton HIT Design software. Halton HIT Design enables

product selection and performance simulation for the product(s) that addresses, e.g., air velocity, cooling and

heating capacity, throw pattern, and sound level.

Performance values are presented for operation with HVC in position 3.If Lmin > 5 m then use HVCThe impact of HVC compared to presented values in average:position 2: -21% of Pw and Position 1: -38 % of PwLeff Effective length, length of cooling coil, mm Pa Primary air cooling capacity, W Pw Coil capacity, WNZ Nozzle type

DPtot Chilled beam chamber pressure, Pa Lmin Minimum distance between central lines of two supply units, mLd Distance from the supply unit, at which air jet detaches from ceiling, m

Pa 72 108 144 180 216 252 288

qv l/s 10 15 20 25 30 35 40

m3/h 36 54 72 90 108 126 144

Leff

1200 Pw 258 299 325

NZ/DPtot B/71 C/90 D/79Lmin 2,2 5 5

Ld 2 3,2 3,2

1500 Pw 337 405 417 435

NZ/DPtot A/124 B/103 C/105 D/82Lmin 3 3 5,8 5

Ld 2,2 2,4 3,4 3

1800 Pw 366 439 566 5

NZ/DPtot A/88 B/72 B/129 C/117Lmin 2,2 2,2 3,8 4,6

Ld 1,8 1,8 2,4 3,4

2100 Pw 394 556 604 737 682 759

NZ/DPtot A/66 A/148 B/95 B/149 C/126 D/113Lmin 2,2 3,4 4 4,2 6 5,6

Ld 1,8 2,4 2,2 2,4 3,4 3,0

2400 Pw 592 641 780 743 823 808

NZ/DPtot A/116 B/74 B/115 C/99 C/134 D/89Lmin 2,2 2,2 3,4 2,2 4 5

Ld 2 1,8 2,2 3 3,4 3

2700 Pw 625 676 821 965 888 972

NZ/DPtot A/93 B/59 B/92 B/132 C/108 C/141

Lmin 2,2 1,8 2,6 3,8 5,4 6,2

Ld 1,8 1,8 2 2,4 3 3,4

Pre-selection example•Roomdimensions 2.5x4x2.8=10m2 •Airflowrate 1.5l/s/m2 (optiontoincreaseto 2l/s/m2) •Requiredcoolingcapacity 75W/m2

•Availablepressurelevel 110Pa•Airflowrate 15l/s(...20l/s)•Coolingcapacity 750W•Primaryaircapacity(seetable) 108W(144W)•Requiredcoilcapacity 642W(606W)•SelectCCE/B-2700-2400

26 27


1. Design data in cooling

•Insertthesupplyairflowrateandtemperature

•Specifythetemperaturedifferencebetweenthe

inlet and outlet water of the beam, or, optionally,

insert the inlet water temperature and target water

flow rate.

•CalculatethecoilcapacityusingHITDesign,and

compare the coil capacity against the requirement.

•Notethecapacitiestransferredbythecoiland

primary air.

2. Chilled beam location and velocity control

adjustment

•Thelocationandnumberofchilledbeamsare

specified (also, asymmetric positioning is possible).

•TheHVCpositionsaresettoallowadjustingthe

throw pattern in the space and providing the

required velocity conditions in the occupied zone.

•Toprovideadaptabilitytoloadvariations,use

velocitycontrol(HVC)position2(normalposition).

3. Air quality control adjustment

•SettheHAQairflowratetomatchtherequired

room air flow rate.

•HAQcontrolcanbeusedtoadjusttheairflowrate

at a specified duct pressure level.

4. Space results / unit performance

•Checktheoperationparametersagainstsystem

operation conditions to verify that the operation

parameters correspond to those of the system.

5. Design data in heating

•Analysisisasinthecoolingcase.

6. Space results / unit performance in heating

•Analysisisasinthecoolingcase.

Selection

Calculate the cooling and heating capacity of the selected chilled beam units by studying chilled beam performance

in the chosen model rooms with desired operation parameters, with Halton HIT Design.

Design data window in Halton HIT Design selection.

Room dimensions, occupied zone, and design criteria are specified in the ‘Room’ window in Halton HIT Design.

1, 5 2

3

4, 6

26 27

Indoor climate conditions’ design

4.2 m

4.0 m

v3

Study the supply air throw pattern properties and

room air velocities (in design case)

•Roomairvelocitiesinoccupiedzonewithinsetlimits

(non-isothermal and isothermal cases)

•Temperaturedifferencebetweenairjetandroomair

•Distanceatwhichthejetdetachesfromthe

ceiling(Ld)

•Pressurelosslowerthantheavailablepressurein

the duct (check that the noise level is within the

limits set)

•Adjustabilityoftheairflowrate

In cases involving several units; check the impact of

jet interaction on occupied zone boundary velocities

(refertoLminintheleaflet'squickselectiontable).

3.10. Indoor climate conditions’ design

Simultaneouslywiththeperformancevalues,verifyalsothatpredictedtheroomconditionsareacceptable,

providing efficient air distribution but eliminating draught risks.

Check supply air throw pattern in heating

Simultaneouslywiththeperformancevalues,verify

also that the predicted room conditions are

acceptable, providing efficient air distribution:

•Supplyairthrowpatternandroomairvelocities(HVC

position as in cooling)

•Supplyjetadequatelyreachingoccupiedzonelevel

•Flowwatertemperaturewithinrecommendedrange

•Heatingcapacity

•ImpactoftheHVCarrangement

•ImpactoftheHAQarrangement

Study optional room modules

•Unitpressuredrop(keepatthesamelevelas

before)

•Operationwithoptionalroomcoolingloadlevels/

room usage

•ImpactofHVCinotherpositions(1and3)

•ImpactoftheHAQarrangement

•Operationinoptionalroommoduleconfigurations

If targets for indoor climate condition are not met,

•changethelengthand/or

•beamproperties,oreven

•thebeamtype

Halton HIT Design Performance view (2D).


4.0 m

v3

CCE/A-3800-3500+AQ(0.0)2006.03

Room: Room C

Room size: 4.2 x 4.0 x 3.0 m

Room air: 24.0 °C / 50 %

Heat gain: 0 W

Installation height: 2.90 m

Inlet water temperature: 15.0 °C

Outlet water temperature: 20.1 °C

Water massflow: 0.040 kg/s (2 x 0.020 kg/s)

Coil capacity: 858 W (2 x 429 W)

Water pressure drop: 0.6 kPa

Total supply air flow: 36 l/s (2 x 18 l/s)

Supply air temperature: 18.0 °C

Primary air capacity: 258 W (2 x 129 W)

Total pressure drop: 83 Pa

Total sound pressure level: 19 LpAre 10m2sab

Total cooling power: 1116 W (2 x 558 W)

Dew point temperature: 12.9 °C

HVC position side=1, middle=3

Temperature difference: Tv3=1.2 °C

Ld: -

vmax in occupied zone: v3=0.15 m/s v3(dt=0)=0.10 m/s

vlim = 0.20 m/s

Heat sources and their location may influence to the velocity and direction of the jet.

28 29

Management of room conditions

3.11. Management of room conditions

Air flow measurement can be implemented accurately by measuring the chamber pressure of the chilled beam.

Adjustment and balancing methods

Traditional

In constant-pressure zones, the unitary airflow rate

adjustment does not affect the airflow rates of other

chilled beams. Commissioning can be implemented

very effectively. Furthermore, balancing is not needed

when unitary airflow rates are adjusted, e.g., for office

room space changes.

Evenconstantairflowratesofofficeroomscanbe

integrated into the same ductwork as variable air flow

rate control for meeting rooms.

Water flow rates can be controlled using an automatic

flow limiter and combined control valve for each chilled

beam, enabling individual changes in water flow rates

without the need for balancing.

Additionally, in large systems, differential pressure

valves in the pipework zones may be needed to

ensure appropriate pressure conditions.

Halton Adaptable

Proper operation conditions for chilled beams are

ensured by adjustment of airflow and water flow

rates.

Airflow rates can be adjusted by balancing the

ductwork by means of zone balancing dampers and

the balancing damper of each chilled beam. The

balancing damper can be integrated into the chilled

beam or into the connecting branch. K factors and

safety distances are presented in the HIT Design

software package.

Air flow measurement can be implemented accurately

by measuring the chamber pressure of the chilled

beam. Also, system-powered self-balancing dampers

can be used. A self-balancing damper increases the

total pressure drop to 40 … 150 Pa.

Water flow rates can be adjusted via zone balancing

valves and the balancing valve of each chilled beam.

28 29


Shut-off valve

Balancing valve

Control and balancing valve

Control valve with max flow limiter

Pressure regulator valve

Pressure control damper Duct balancing damper

Adaptable air balancing and adjustment with constant duct pressure.

Traditional balancing of ductwork.

Adaptable control and maximum flow limiting valves. Traditional control and balancing valves.

30 31


Room control sequences Roomthermalconditionstypicallyarecontrolledbyadjusting hot and chilled water flow rates in each chilled beam by means of two-way valves.

Controlcanbebasedonon/off,pulse-width-modulated(PWM), proportional, or proportional integral control. Demand-based control is based on remotely set setpoints determined by, e.g., schedulers, and settings can be adjusted locally by users according to their demands or by occupancy mode as detected by occupancy sensors.

In meeting and team rooms, traditional temperature control can be complemented with an additional sequence for increasing outdoor air flow rate (Halton Air Quality control). This function responds rapidly to varying ventilation requirements.

Proper heating operation can be ensured by using a combination of room and supply air temperature control in order to optimise the supplied air temperature to avoid an excessive vertical room temperature gradient.

Condensation prevention can be arranged in two stages:•Systemflowwatertemperaturecontrolbasedon

room air dew point calculation for critical locations.•Locallyintheroom,usingcondensatedetectionto

close the chilled water valve.

Control sequence for heating and cooling.

Control sequence for heating, air quality (HAQ), and cooling.

Room control applications

Roomcontrolcanberealisedonthebasisof

functional requirements and the desired flexibility level

using:

•Aself-poweredstandalonecontroller•Anelectricstandalonecontroller•Atraditionalcommunicativecontroller•Atemperaturesensor,typicallylocatedinthe

wall-mounted user panel

The control valve and actuator types are selected to

match the required water flow rates and control

sequences.Thepowersupply(24/230VAC)for

controller, actuators, and sensors is supplied on the

basis of the units selected.

30 31

Case study

WP1

WP2

HVC 3 HVC 1

10 %

20 %

WP2

WP1

3.12 Case study: occupant comfort using chilled beams

TheInternationalCentreforIndoorEnvironmentandEnergyoftheTechnicalUniversityofDenmark(DTU)hascarriedout

a study measuring occupant comfort in an office environment where cooling and ventilation were provided by a CBC

chilledbeamequippedwithHaltonVelocityControl(HVC).

Case 1

Chilled beams are installed perpendicularly to the external

wall.Velocityconditionsarepresentedwithacooling

capacityof50W/m2intwodifferentcases:HaltonVelocity

Controlinpositions3and1.Roomairvelocitieswerelower

when induction through beams was lower, even though the

cooling capacity was the same. The primary air flow rate

was the same in both cases, and compensating cooling

capacity was provided by increasing the water flow rate.

Case 2

Human responses were studied with chilled beams installed

parallel to the external wall and two persons occupying the

room. The number of people sensing a draught was clearly

(byabout60%)reducedduringthemaximumcooling

capacityperiodwithHVCinthethrottleposition(1).While

the person near the window surface (WP2) felt slightly

warmer(PMVincreasedfrom0.4to0.7)whenHVCwas

used, the acceptability increased slightly.

Case 1. Air velocities (m/s) in the occupied zone with Halton Velocity Control in ‘full’ position.

Thermal conditions (temperature and velocity) in the occupied zone were measured in this study, along with human responses, using both thermal manikins and living people. The following conclusions were drawn after analysis of the measurement results:

•Highqualityofgeneralthermalcomfortcanbeachieved.

•HaltonVelocityControldecreasesvelocitiesandthepotential risk of draught discomfort.

•Increasedheatloadandsupplyflowratetogetherincrease the risk of local discomfort.

•Airflowinteractionisanimportantfactoraffectingthermal comfort.

•Thelayoutofchilledbeamsandworkplacesshouldbe carefully considered.

•Thermalflowsfromwarmorcoldwindowsareimportant factors in air distribution and occupants’

local thermal comfort.

Case 1. Air velocities (m/s) in the occupied zone with Halton Velocity Control on in ‘throttle’ position.

Case 2 : Percentage of people feeling a draught (70 W / m2).

32 33

Case study

Room air conditioning with CCE chilled beams throughout the floor.

Spaces: Office room A: 11,3 m2

1 pc. of CCE/A 3800-3500Office room B 17 m2 1 pc. of CCE/A 3800-3500 Office room C: 17 m2 2 pcs. of CCE/A 3800-3500 Meeting room D: 34 m2 3 pcs. of CCE/A 3800-3500

Design data: Unit Office space Meeting roomRequired cooling capacity W/m2 60 60Required heating capacity W/m3 35 35Ventilation rate l/s,m2 2 4Sound level dB (A) < 33 < 35

Selected operational parameters: Room air temperature °C 24 Supply air temperature °C 18 Inlet/outlet water temperature °C 15/18 HVC positionsTarget duct pressure level Pa 80 Max. cooling: 180 L/R Left/RightTarget max. water pressure drop kPa 1...5 S/M Side/Middle

Chilled beam case study - Office without suspended ceiling and with flexible meeting rooms

A A / max cooling B C D / meeting room D / office space

Space division, m 1,35 1,35 1,35 1,35 1,35 1,35

Room modules 2M 2M 3M 3M 6M 6M

width x length, m 2,7 x 4,2 2,7 x 4,2 4,05 x 4,2 4,05 x 4,2 8,1 x 4,2 8,1 x 4,2

Area, m2 11,3 11,3 17 17 34 34

Air flow rate, l/s 23 35 34 34 137 68

Air flow from nozzles, l/s 18 26 18 18 18 18

Air flow from HAQ, l/s 5 9 16 0 27 5

Velocity control (HVC) position L/R=3/1 L/R=3/3 S/M=3/3 S/M=1/3 S/M=2/3 S/M=3/3

Water flow rate, kg/s 0.03 0.1 0.045 2 x 0.04 3 x 0.02 3 x 0.033

Cooling capacity of primary air, W 165 251 244 258 982 487

Cooling capacity of coil, W 509 1184 712 858 (2x429) 1419 (3x473) 1857 (3x619)

Total cooling capacity, W 674 1435 956 1116 (2x558) 2401 (3x800) 2344 (3x781)

Total cooling capacity, W/m2 59 127 56 66 70 69

The task is to select a chilled beam for an office space with a design grid of 1.35 m. Typical office rooms are either2or3moduleswide.Seethedesigndatainthetablebelow.Thefollowingdesigntargetsareset:•Minimalinstallationsandadjustmentswhenofficelayoutisalteredorofficesarechanged into team or meeting rooms and vice versa•Samechilledbeamunittypeandsizethroughouttheofficearea•Sameductpressurelevelforallunits•Waterflowrateusedforcapacityadaptation

A B C

D

32 33

Passive chilled beam system

4.1. Passive chilled beam system

Chilled beam system description

Halton’s chilled beam system is an air conditioning

system for cooling applications where good indoor

climate and individual space control are appreciated.

The passive chilled beam system utilises the excellent

heat transfer properties of water and provides a good

indoor climate energy-efficiently.

Operation of the system

Chilled beam systems are designed to use the dry

cooling principle, operating in conditions in which

condensation is prevented by control applications.

Ventilation

Ventilationinpassivechilledbeamsystemstypicallyis

arranged using mixing ventilation with ceiling or wall

diffusers. Alternatively, floor diffusers can be used.

In passive-service chilled beams, a diffuser can be

integrated into the beam unit for air supply.

Cooling

Chilled water circulates through the heat exchanger of

the passive chilled beam unit, resulting in relatively

high cooling capacities.

Passive beam operation is based on free convection in

the heat exchanger. Passive chilled beam units with a

higher proportion of radiation also exist.

Heating

Heating generally is realised with a separate heating

system.

•Aseparateheatingsystem–e.g.,perimeterheating

– typically is used in passive chilled beam

installations.

•Windowdraughtsduetoradiationanddownward

convective air movement during cold seasons need

to be eliminated.

Schematic diagram of a chilled beam system office floor installation.

34 35

4.2 Chilled beam system design

A passive chilled beam system can be designed to fulfil requirements for sustainable, energy-efficient buildings that

provide flexible use of space and a healthy and productive indoor climate. A passive chilled beam system can realise

excellent indoor climate conditions in terms of thermal and acoustic properties in a wide range of installation scenarios

TYPICAL INPUT VALUES AND OPERATION RANGES

Room temperature, summer 23..25 °C

Room temperature, winter 20..22 °C

Water inlet temperature, cooling 14…16 °C

Target water flow rate 0.02…0.06 kg/s

Sound pressure level < 35 dB(A)

Cooling capacity / floor area … 80 W/m2 …120 W/m2 *

Cooling capacity / effective unit length … 250 W/m … 400 W/m *

Separately for ventilation

Supply air temperature 16 ... 19 °C

Outdoor air flow rate/ floor area,

offices 1.5 … 2.5 l/s/m2 5 … 9 m3/h/m2

meeting rooms 1.5 … 4 l/s/m2 5 ... 15 m3/h/m2

Note * It is reasonable to study the room air velocity conditions carefullyNote ** It is reasonable to study the thermal conditions carefully

Ventilation and air diffusion arrangement

•Thesupplyairflowrateshallbehighenoughto

remove internal humidity loads.

Cooling using chilled beams

•Requiredcoolingcapacitiesshouldbenomorethan

60…90W/m2. With well-dimensioned integrated

applications,capacitiesasgreatas120W/m2 can be

realised.

•Thermalpropertiesoftheexternalwallsand

window construction should be reasonable.

•Airtightwindowswitheffectivesolarshadingare

used.

•Thecoolingcapacityofpassivechilledbeamsis

typically150…250W/mtoavoiddraughtsinthe

occupied zone, especially underneath the unit.

Operation shall be designed with conditions in the

occupied zone in all seasons (winter, summer, and

intermediate season) taken into account.

•Theflowwatertemperature(typicallyabove14°C)

must be sufficiently high to avoid condensation in all

operation conditions. If necessary, the inlet water

temperature may be adjusted to compensate for

outdoor or indoor conditions. A condensation sensor

should be located in each zone.

•Waterflowratesandpressuredropsinchilled

beams should be in line with chilled water pipework

design and pumping cost target levels.

•Passivechilledbeamsinstalledinasuspended

ceiling always require sufficiently large openings in

the ceiling for the induced room air path.

Locationofchilledbeamsshallrespecttheminimum

distances from walls and ceiling presented in the

section ‘Passive chilled beam orientation and

ventilation arrangements’.

Passive chilled beam system design

34 35

The appropriate model of passive chilled beam unit is selected by taking into account the following factors: • Architecturaldesign•Preferredappearance•Exposedinstallationorflushmountinginsuspendedceiling•Hiddeninstallationaboveperforated/gridceiling•Adaptationtoceiling•Positioninginconsiderationoflightfittings•Integrationoflightfittings

•Unitdimensions•Roomdesigngriddimensions•Requirementsforflexibilityandeventualpartitionwalllocations

•Supplyairdiffuserintegration•Exhaustvalveintegration•Coolingcapacityrequirements

A passive beam can be integrated into a suspended ceiling via a ceiling plenum, allowing closed return air circulation.

Building services can be integrated into chilled beams, creating an elegant and uniform ceiling appearance. Multi-service passive beams are a cost-effective and interesting concept especially for renovation projects where there is a desire to maximise ceiling height or existing ceiling appearance should be largely preserved.

Common technical services for integration are:•Lightfittings,controls,sensors,detectors,andcabling

4.3. Passive chilled beam model selection

Passive beams in ceiling void

Customised customized service beam.

Closed passive chilled beam integrated into suspended ceiling.

Passive chilled beam in exposed installation.

Passive chilled beam in ceiling-void-mounted installation.

Passive chilled beam model selection

36 37

Passive chilled beams in exposed installation.

Customized service beams in exposed installation.

Passive chilled beam model selection

Passive beams in ceiling void

36 37

4.4. Passive chilled beam orientation and ventilation arrangements

Passive chilled beams can be installed either perpendicularly or parallel to the perimeter wall. The units should not

be positioned directly facing work spaces, to ensure comfortable velocity conditions. Minimum recommended

installation distances from walls and between parallel chilled beams shall be respected, for proper cooling

performance.

Side wall installation & ceiling diffuser.

Ceiling diffuser between chilled beams.

Selection of passive chilled beam orientation•Indoorclimateconditions•Capacityperchilledbeamunit•Residualvelocitiesfortheoccupiedzone•Convectiveplumeinteractionwithsupplyairjet•Suitabilityforroommoduledimensions

•Suitabilityforthelightingfixturelocations•Flexibilityforlayoutchanges•Minimumdistancebetweenparallelbeams•Minimumdistancebetweenchilledbeamandwall/

ceilingThere are various combinations for positioning chilled beams and supply air diffusers.

Perimeter installation & ceiling diffuser.

Side wall installation & wall diffuser.

Side wall installation & floor diffuser. Side wall installation & low-velocity unit.

Passive chilled beam orientation and ventilation arrangements

38 39

Passive chilled beam location

Chilled beam units shall be installed respecting

minimum recommended distances from walls and

ceiling in order to ensure effective convection and

proper operating conditions:

H1=min.0.25xWwhenS>W

H2=min.0.5xWwhenS<W

MinimumdistancebetweenchilledbeamunitsofL,

to ensure effective operation:

L=min.3xW

When a passive chilled beam is installed above a

perforated or grid ceiling, the following minimum

distances should be respected:

H3=min.25mm

The open area percentage (OAP) of the suspended

ceiling shall be sufficiently high to ensure proper

functioning of the chilled beam.

The minimum percentage of open area for perforation

is 25%. The minimum hole diameter is 2 mm.

Sidepanelextensionscanbeusedtoimprove

buoyancy effect and thus cooling capacity.

Use HIT Design for calculation of cooling capacity,

taking installation above the perforated ceiling with or

without side panel extensions into account.

Exhaust air unit location

In cases where chilled beams are installed above a

suspended ceiling, exhaust units should not be

installed above the suspended ceiling.

Otherwise, exhaust unit position is of minor

importance in the installation.

Minimum distances for passive chilled beam installation.

Passive chilled beam installed above a perforated or grid ceiling.

Passive chilled beam orientation and ventilation arrangements

Hsk, Correction factor, mm

100 1.19

150 1.28

300 1.40

400 1.45

Side panel extension effect on cooling capacity.

38 39

Operation range definition

4.5. Operation range definition

Chilled beam operation range is defined on the basis of representative rooms. The selected rooms are studied to

determine cooling and heating loads. After specification of load patterns in the representative rooms, chilled beam

operation parameters are set. The design target values can be verified via a full-scale mock-up or computational fluid

dynamics (CFD) simulation.

Typical input values and operation ranges (extreme target values in brackets)

Room temperature for cooling 23..25 °C

Water inlet temperature for cooling 14…16 °C

Target water flow rate for cooling 0.02…0.10 kg/s

Cooling capacity per unit floor area …80 (120) W/m2

Cooling capacity / effective beam length 250 (400) W/m

Comfort / PMV -0,5...+0,5

Draught rate (DR) <15%

Local mean room air velocity cooling 0,23 m/sheating 0,18 m/s

Definition of design conditions and operation

parameters

•Coolingcapacitydemandinspaces,inW/m2, and


•Heatingcapacitydemandinspaces,inW/m2, and


•Ventilationarrangement

•Diffusertype,size,andnumber

•Ventilationratesinspacesasrateperfloorarea,in

l/s/m2

•Ventilationrateinspacesasrateperperson,in

l/s/person

•Modelroomsandoperationalparameters

•Roomtemperature

•Supplyairtemperature

•Waterinlettemperature

•Targetductpressurelevel

•Targetwaterflowrate

•Maximumsoundpressurelevel

Verification of target design values with full-scale mock-up and CFD simulation.

40 41


Pre-selection

With the help of quick-selection tables, pre-select the

chilled beam using the following parameters for the

desired design conditions:

•Indoorclimateconditions

•Coolingcapacity

•Minimumdistancebetweenparallelunits

4.6.Pre-selectionandselection

Make your design process more efficient. Halton’s design tools for the pre-selection and selection phase include

brochure data sheets with quick-selection charts and the Halton HIT Design software. Halton HIT Design enables

product selection and performance simulation for the product(s) that addresses, e.g., air velocity, cooling and

heating capacity, throw pattern, sound level, and location of the units.

CPA cooling capacity, in watts per metre of effective length

Water flow rate: 0.08 kg/s

Difference between room air and water mean temperatures,degC

Coil height (mm) Coil width (mm) 6 7 8 8.5 9 9.5 10 11

75 315 86 107 131 144 157 170 183 212

75 465 136 170 207 228 248 269 290 335

75 615 180 226 276 294 312 349 386 446

100 315 102 126 153 167 181 196 209 242

100 465 168 208 252 276 300 323 345 400

100 615 214 266 322 352 382 411 440 510

Pre-selection example•Roomdimensions 2.5x4x2.8=10m2 •Roomtemperature 24°C•Ventilationrate 20l/s•Supplyairtemperature 18°C•Requiredtotalcoolingcapacity70W/m2

Cooling capacity 700 W•Coolingbyventilation 144W•Coilcoolingcapacity 566W•PresumedtemperaturedifferenceDT=8degC•SelectCPA-100-3900-315-1 153W/m

Chilled beam CPA cooling capacity, in watts per metre of effective length for water flow rate 0.08 kg/s.

CPA passive chilled beam quick-selection

Coolingcapacityoverunitlength(W/m)presentedfor

water flow rate qmw=0.08kg/s.

Estimatethetemperatureriseinthechilledbeam

(typically 1 … 3 °C), and calculate the temperature

difference between room air and water mean

temperature.

Temperature difference Tr - (Tw1 + Tw2)/2,degC

Where

Tr Roomtemperature,°C

Tw1 Water flow temperature, °C

Tw2 Water return temperature, °C

Check the temperature difference with the HIT Design

software.

Water flow rate

qmw 0.015 0.02 0.025 0.03 0.035 0.04 0.045 0.05 0.055 0.06 0.08

kg/s 0.79 0.83 0.86 0.88 0.91 0.92 0.94 0.96 0.97 0.98 1

Correction factor of cooling capacities for water flow rates deviating from 0.08 kg/s flow rate

40 41


1. Design data in cooling

•Specifythetemperaturedifferencebetweenthe

inlet and outlet water of the beam or, optionally,

insert the inlet water temperature and target water

flow rate.

•CalculatethecoilcapacityusingHITDesign,and

compare the coil capacity against the requirement.

•Youcanalsoinsertthesupplyairflowrateand

temperature for total cooling capacity calculation.

2. Chilled beam location and velocity control

adjustment

•Thelocationandnumberofchilledbeamsare

specified (also, asymmetric positioning is possible).

Youcanalsoadda‘person’forevaluatingtheair

velocity locally

•directlybelowthechilledbeam

•inthevicinityofthebeamatfloorlevel

•furtherfromthechilledbeamatfloorlevel

3. Space results / unit performance

Check operation parameters against system

operation conditions to verify that the operation

parameters correspond to those of the system.

as in the cooling case.

Selection

Calculate the cooling and heating capacity of the selected chilled beam units by studying chilled beam performance

in selected model rooms with desired operation parameters, using Halton HIT Design.

Design Data window in Halton HIT Design selection.

Room dimensions, the occupied zone, and design criteria are specified in the ‘Room’ window in Halton HIT Design.

1 2

3

42 43


If indoor climate conditions targets are not met,then change•thebeamlengthornumberofbeamsand/or•beampropertiesoreven•beamtypeand•diffusertypeand/orlocation

Study optional room modules•Waterflowrate(keepatthesamelevelasbefore)•Operationatoptionalroomcoolingloadlevels/room

usage

4.7. Design of indoor climate conditions

Simultaneouslywiththeperformancevalues,verifyalsothatthepredictedroomconditionsareacceptable,

particularly the air velocities entering the occupied zone created by the convective plume of the chilled beam. Take

into consideration the interaction of the passive beam and the supply air distribution as well.

•Operationinoptionalroommoduleconfigurations

Study the velocities of the convective plume entering the occupied zones and room air velocities•Plumevelocitiesenteringtheoccupiedzones(inthe

design case)•Roomairvelocitiesintheoccupiedzone•Temperaturedifferencebetweentheplumeand

ambient room air

Check the interaction of the falling convective plume of a chilled beam and supply air throw pattern

Simultaneouslywiththeperformancevalues,verifythat the predicted room conditions are acceptable, providing efficient air distribution.

•Supplyjet–adequatelyreachingtheoccupiedzonelevel

•Supplyairthatisnotdirecteddirectlytochilledbeam air circulation


Stationary person below and to the side of a chilled beam.

Interaction of convective plumes of a chilled beam

and a stationary person

Notethattherisingconvectiveplumeofastationary

Stationary person located directly below a chilled beam.

person affects the flow pattern of a chilled beam and

that the prevailing velocities above the person are

lower than in ‘undisturbed’ flow created by a chilled

beam.

2.5 m

vop

CPA-100-3900-315-1Cooling 2007.05

Room:

Room size: 2.5 x 4.0 x 2.8 m

Occupied zone: h=1.8 m / dw=0.5 m

Room air: 24.0 °C / 50 %

Heat gain: 700 W

Perforated ceiling: -





Coil capacity: 575 W

155 W/m


Supply air flow rate 20 l/s

2.0 l/(sm2)


Jet outlet temperature: 21.4 °C

Primary air capacity: 143 W

Total pressure drop: -

Total sound pressure level: -

Total cooling capacity: 718 W

72 W/m2


Velocity control: -

Velocity point

v

T

vop

~0.15 m/s

vlim = 0.20 m/s

2.5 m

v3

vop

CPA-100-3900-315-1Cooling 2007.05

Room:

Room size: 2.5 x 4.0 x 2.8 m


Room air: 24.0 °C / 50 %

Heat gain: 700 W







155 W/m



2.0 l/(sm2)







72 W/m2


Velocity control: -

Velocity point

v

T

v3

~0.25 m/s

-2.6 °C

vop

~0.15 m/s

vlim = 0.20 m/s

2.5 m

v3

vop

CPA-100-3900-315-1Cooling 2007.05

Room:

Room size: 2.5 x 4.0 x 2.8 m


Room air: 24.0 °C / 50 %

Heat gain: 700 W







155 W/m



2.0 l/(sm2)







72 W/m2


Velocity control: -

Velocity point

v

T

v3

~0.25 m/s

-2.6 °C

vop

~0.05 m/s

vlim = 0.20 m/s

42 43

Adjustment and balancing methods

Proper operation conditions for chilled beams are

ensured by correct water flow rates.

Water flow rates can be adjusted via zone balancing

valves and the balancing valve of each chilled beam.

Water flow rates can also be controlled using an

automatic flow limiter and combined control valve for

each chilled beam, enabling individual changes in

water flow rates without the need for balancing.

Additionally, in large systems, differential pressure

valves in the pipework zones may be needed to

ensure proper pressure conditions.

4.8.Managementofroomconditions

Water flow measurements can be implemented by measuring pressure drop over a balancing valve equipped with

measurement taps.

Room control

Roomthermalconditionstypicallyarecontrolledby

adjusting hot and chilled water flow rates in each

chilled beam by means of two-way valves.

Controlcanbebasedonon/off,pulse-width-modulated

(PWM), proportional, or proportional integral control.

Demand-based control is based on remotely set

setpoints determined by, e.g., schedulers, and settings

can be adjusted locally by users according to their

demands or by occupancy mode as detected by

occupancy sensors.

44 45

Customised service beams

5. Customised service beams

Traditional chilled beam installations include ventilation, cooling, and heating next to the equipment for other ceiling-

based services. The customised service beam concept proposes an all-in-one solution for all ceiling-mounted

accessories. The service beam concept is suitable for both suspended-ceiling and exposed installations. The

product'sappearancecanbetailoredtosuittheinterior.

The concept offers benefits from the time of installation through a whole lifetime of use:

•Animprovedindoorclimateisaresultofexcellent

temperature conditions and silent, draught-free

operation. Good conditions promote productivity and

the health of users.

•Flexibilityfordifferentlayouts,fromopen-planto

partitioned office space, is achieved efficiently.

•Assemblyatthefactoryincreasesinstallationspeed

andqualitywhilereducingcosts.Rapidconnections

further reduce the commissioning time on-site.

•Havingasinglesourceofresponsibilitylowersrisk

and reduces the need for co-ordination.

Luminairescanbeintegratedintochilledbeamsor

installed as separate light fittings, regardless of chilled

beam orientation. Chilled beams are available with

directand/orindirectluminaires.

•Withfewerseparatepiecesofequipmentfixedto

the ceiling and walls, interior design better matches

the architectural vision.

•Theinvestmentcostismorecompetitivethanthatof

traditional systems and suspended-ceiling

installations with separate building services.

•Competitiverunningcostsareachievedwithlow

maintenance demands and energy consumption.

•Roomheightisincreased,asnosuspendedceiling

is needed.

Luminaires

Direct and indirect luminaires integrated into the

bottom plate of the beam provide good contrast and

visual comfort. Direct and indirect lighting can be

implemented with separate light fittings or with one

fitting for both. All lights can be equipped with built-in

on/offordimmablecontrolanddifferentconnection

options.

Also, emergency lights can be integrated into the

chilled beams.

44 45

Customised service beams

Detectors

Occupancy sensors allowing for demand-based

ventilation and other occupancy-related features, as

well as daylight sensors and smoke detectors, can be

integrated into the chilled beam.

Controls

Chilled beam delivery can include integrated two-way

control valves with actuators and condensation

sensors. When necessary, the beam structure can also

include a room controller and the associated

temperature sensor.

Space for sprinklers

Nationalbuildingcodestypicallyrequiresprinkler

installations to be carried out on the site.

However, the sprinkler pipes can be attached above

the beams and the pipe connections for individual

sprinkler nozzles, to an accessory space in the middle

of the beam.

Public address loudspeakers

Public announcements or background music can be

provided through built-in pre-wired speakers.

Cable shelves

Cables for various services can be laid on cable

shelves, which can be integrated in the chilled beam

design in order to complete the elegant installation.

46

Care for Indoor Air

www.halton.com

Documents

Chilled Beam Design Guide