Post on 12-Apr-2015
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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
Indoor climate conditions
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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Adaptable chilled beam concepts
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.
Adaptable chilled beam concepts
Halton CCC with air quality control in a meeting room.
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Adaptable chilled beam concepts
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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Adaptable chilled beam concepts
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
Adaptable chilled beam concepts
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.
Adaptable chilled beam concepts
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
Adaptable chilled beam concepts
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
actual breakdown of loads
•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
Pre-selection and selection
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).
Halton HIT Design Performance view (3D).
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
Management of room conditions
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
Management of room conditions
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
actual breakdown of loads
•Heatingcapacitydemandinspaces,inW/m2, and
actual breakdown of loads
•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 and selection
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
Pre-selection and selection
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
Indoor climate conditions
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
Halton HIT Design Performance view (2D).
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: -
Installation height: 2.70 m
Inlet water temperature: 15.0 °C
Outlet water temperature: 16.7 °C
Water flow rate: 0.080 kg/s
Coil capacity: 575 W
155 W/m
Water pressure drop: 5.6 kPa
Supply air flow rate 20 l/s
2.0 l/(sm2)
Supply air temperature: 18.0 °C
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
Dew point temperature: 12.9 °C
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
Occupied zone: h=1.8 m / dw=0.5 m
Room air: 24.0 °C / 50 %
Heat gain: 700 W
Perforated ceiling: -
Installation height: 2.70 m
Inlet water temperature: 15.0 °C
Outlet water temperature: 16.7 °C
Water flow rate: 0.080 kg/s
Coil capacity: 575 W
155 W/m
Water pressure drop: 5.6 kPa
Supply air flow rate 20 l/s
2.0 l/(sm2)
Supply air temperature: 18.0 °C
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
Dew point temperature: 12.9 °C
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
Occupied zone: h=1.8 m / dw=0.5 m
Room air: 24.0 °C / 50 %
Heat gain: 700 W
Perforated ceiling: -
Installation height: 2.70 m
Inlet water temperature: 15.0 °C
Outlet water temperature: 16.7 °C
Water flow rate: 0.080 kg/s
Coil capacity: 575 W
155 W/m
Water pressure drop: 5.6 kPa
Supply air flow rate 20 l/s
2.0 l/(sm2)
Supply air temperature: 18.0 °C
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
Dew point temperature: 12.9 °C
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
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