Enabling Wellbeing

Halton – Vario Design Guide

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Table of contents

1. Halton Vario - ventilation and air conditioning system overview 3

1.1 Room level, Zonal level and central level 4

1.2 Flexible design and adaptable HVAC systems reduce churn costs 6

2. Room level 8

2.1 Requirements for design of indoor environment and cooling demand 9

2.2 Air water system 12

2.2.1 Operation (demand based ventilation and VAV beam principle) 12

2.2.2 Layout and control zone considerations 15

2.2.3 System & component overview 16

• Halton Rex chilled beams 16

- Integration of controls into chilled beams 16

• Controls 16

2.3 All air system 18

2.3.1 Operation (demand based ventilation and VAV beam principle) 18

2.3.2 Layout and control zone considerations 21

2.3.3 System & component overview ??

• Active diffusers and controls ??

- Integration of controls into room units ??

• Controls ??

3. Zonal level 24

3.1 Operation based on constant pressure ductwork 24

3.1.1 Principle Design of constant pressure ductwork 28

3.1.2 System & component overview 32

• Ductwork components 32

• Controls 32

3.1.3 design examples 33

4. Central level

4.1 Operation ??

4.2 System and component overview ??

4.3 Design examples ??

5. Communication

5.1 Lon, Backnet, Modbus ??

5.2 Network structure ??

5.3 Communication with slave units ??

2 3

In Halton Vario system, energy and environmental

efficiency is implemented together with good

indoor environment quality and wellbeing of users.

Indoors conditions are maintained by demand-

based and only when the spaces are occupied the

indoor conditions are actively controlled.

Halton Vario system's adaptable indoor conditions

impact on:•Usershealth•Userscomfort•Energyefficientoftherealestate•Carbonfootprintoftheenergyuse•Adaptabilityforfutureusers’needs•Reliabilityandsafetyforoperation•Assetvalue

Thoseitemsgivebenefitsfordevelopers,tenantsand

ownerstoruntheiroperationmoreeffectivewayand

improvetheirprofitable.Thebenefitsfordifferent

stake-holdersaresummarizedinthetable1.

1.HaltonVario-ventilationandairconditioningsystemoverview

Halton Vario overview

Table 1. Halton Vario system's benefits for developer, tenants and owners.

Developer Tenants Owners

Higher return of investment (ROI) Health and comfort of employees Lower risk

Lower risk of investment Productivity of workers Lower life-cycle costs

Easier to get financing Better brand Easier to rent

Easier to sell Can employ better people Lower churn costs of continuous changes

Easier to adapt changes during construction phase

Fast and easy layout changes for alteration use of space

Less IEQ complains

4

Fig. 1. Halton Vario system air-water concept.

Halton Vario air-water system

The system is based on smart controls and Halton Vario system’s chilled beams. Halton Vario is a total system for ventilation, cooling and heating in rooms together with the required controls at room, zonal and system level.

Halton Vario air- water system provides solution for room, zonal and central levels:

RoomsHaltonVariosystem'schilledbeamsareusedinofficerooms,openplanofficeandmeetingrooms.Inoffices,unoccupiedoroccupiedspace,theairflowisadjustedaccordingly.Inmeetingrooms,airflowisadjustedfromminimumtomaximum.ControlofconditionsisbasedonCO2,temperatureandoccupancy.Theroomcontrollerensuresperfectconditionsinoccupiedworkplacesandsavesenergywhenspacesareunoccupied.Intheroomcontrolsystem,thereshouldbeintegratede.g.windowswitchandcondensationsencortopreventcondensation.

ZonesHaltonVariosystemdividesthesystemintoventilationzonestoensureflexibilityandcontrollabilityofairflowratechangesindifferentspaces,thatenableslinearoperationofcontroldamperofchilledbeamandmakespossibletointegrateconstantairflow(CAV)andvariableairflowrate(VAV)roomunitsintosameductbranch.Constantstaticpressurezonesenablelayoutflexibilityandminimizethechurncostwhilemakingtheadjustmentsimple.

System levelHaltonVariosystem'sOptimizermonitorstheperformanceoftheventilationsystem.Itminimisesenergyconsumptionbykeepingthelowestpossiblepressureintheductworkthatisrequiredforoperation.Thepositionsofzonedampersaremonitoredandthesystemoptimizesthepressurelosssothatunnecessaryhighpressuredropdoesnothappeninzonedampers.

HaltonVarioair-watersystemisonethemostenergyefficientsolutionresultinginupto50%energysavingscompared to typical non-demand based controlled air-watersystem.TheschemeofthewholeHaltonVarioair-watersystemispresentedinFig.1

Halton Vario overview

1.1HaltonVariosystemofferssolutionsforbothair-waterandall-airwaterventilationandair-conditioningsystems

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Fig. 2. A schematic of the whole Halton Vario all-air system.

Halton Vario overview

HaltonVariosystemislowtemperatureheatingandhightemperaturecoolingsystem.Thus,coolingenergycouldbeprovidere.g.fromchiller,freecoolingorgroundcoupledsystems.Lowtemperatureheatingcanbeprovidedfrome.g.districtheating,boilerorheatpumpsystems.Intheair-handlingunit,thesupplyairtemperatureandairflowratesarecontrolled.Atair-handlingunit,thesupplyairisdehumidifiedtopreventcondensationduringsummerconditions.

Halton Vario all-air system

The Halton Vario system is based on smart controls and active diffusers. Halton Vario all-air system is for ventilation and cooling in rooms with controls at room, zonal and system levels.

HaltonVariosystem’sall-airsystemprovidessolutionforroom,zonalandcentrallevels:•Rooms:HaltonVarioactivediffusersforofficerooms,openplanofficesandmeetingrooms.Inofficesandmeetingrooms,unoccupiedoroccupiedspace,theairflowisadjustedaccordingly.ControlofconditionsisbasedonCO2,temperatureandoccupancysensor.Theroomcontrollerensuresperfectconditionsandsavesenergywhenspacesareunoccupied.

ZonesHaltonVariodividesthesystemintoventilationzonestoensureflexibilityandcontrollabilityofairflowratechangesindifferentspaces.Constantstaticpressureismaintainedinzonalductworks.Zonesallowregulatingtheventilationsystemthemostefficientwaybyreducingunnecessarypressureinthesystem.Constantstaticpressurezonesenablelayoutflexibilityandminimizethechurncostwhilemakingtheadjustmentsimple.•System level:HaltonVariosystem'sOptimizermonitorstheperformanceoftheventilationsystem.Itminimisesenergyconsumptionbykeepingthelowestpossiblepressureintheductworkthatisrequiredforoperation.Thepositionsofzonedampersaremonitoredandthesystemoptimizesthepressurelosssothatunnecessaryhighpressuredropdoesnothappeninzonedampers.

TheschemeofthewholeHaltonVarioall-airsystemispresentedinFig.2.

Intheair-handlingunit,thesupplyairtemperatureiscontrolled.Supplyairflowrateisthemasterthatexhaust(slave)follows.Thefanpoweriscontrolledtoproviderequiredoperationconditionsofthebranchcontroldampers.

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Halton Vario overview

Table 2. Adapting space types and business processes in office buildings.

Space Interaction Autonomy Operation Example

Hive low low customer service

call centre

Cell low high support tasks

financial administration

Den high low team work media

Club high high expert work

consultancy

The adaptability of office space is one of the main

issue in designing a system for sustainable

buildings. In a modern office environment, balance

is sought between work performed by individuals

and in interaction between employees. The systems

must adapt to changed loads and partition wall

locations. For a room system, adaptability means

taking changes in the supply air flow, cooling effect

and throw pattern of the supply air device into

consideration. All this makes possible to change

office to meeting room quicly and cost-effectively.

The functionality of the workspace significantly affects

the productivity of employees. Often a compromise

must be made among the needs of the employee,

team and organisation when arranging workspaces.

Addressing the interaction and privacy needs of

employees, both of which are important considerations

in organisations, is particularly challenging. In general, it

can be stated that, from the perspective of dispersing

silent information (views, experiences, intuitions), fully

autonomous workspaces do not support the business

models of most companies. On the other hand,

reducing the autonomy afforded by individual

workspaces reduces acoustic privacy, which disturbs

concentration.

Organisational changes in most companies are

continuous and require flexible changes in work

methods and workspaces. The traditional oneperson

office areas, or cells, and open offices, or hives, seen in

traditional offices are today changing into spaces that

are more suited to team work, referred to as dens or

clubs (Table 2).

1.2FlexibledesignandadaptableHVACsystemsreducechurncosts

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Table 3. Churn costs of traditional system.

Costs of traditional system Cost

Design work 30 - 40 €/m2

Changes in automation systems 10 - 20 €/m2

Changes in mechanical systems 40 - 100 €/m2

Changes in electrical systems 30 - 40 €/m2

TOTAL 110 - 200 €/m2

Movingpeopleisexpensive.Thecostofamove

dependsontheextenttowhichthefacilitymustbe

modifiedtoaccommodatethechanges.Oftennew

walls,neworadditionalwiring,new

telecommunicationssystems,orotherconstruction

areneededtocompletethemove.

Whenthenumberofoccupantsortheuseofthe

spacechanges,theindoorenvironmentqualityand

thesystemperformanceshouldalwaysbechecked.

Dependingontheselectedsystems,thecostof

modifyingaspaceandvariesalot.Withtraditional

system,thecostsareeasilyover100€/floor-m2 and

thetotalrequiredtimeincludingdesignandretrofitting

is1…3months.

InTable3,presentstypicalcostswhentheoffice

spaceismodifiedtomeetingroomwithtraditional

system.

Butchangecanbeeasy-churncostsandtherequired

timeforthechangecanbeminimizedifthesystemis

adaptable.Halton’sVariosystemprovidesminimized

churncostsandtimeforthechange.Thechangeof

officetomeetingroomhappenswithin15minutes.

Halton Vario overview

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Room level

2.Roomlevel

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For the selection of room units, the required

ventilation rate must be specified based on

national requirements or using the recommended

methods in the standard. As a minimum, space

must be ventilated to dilute the bio effluents from

the occupants. In addition, the air flow rate is

increased to take into account the emissions from

the building materials. Recommended airflow rates

for diluting emissions are categorized. Typically

good and excellent level of air quality requires 1.5

– 2.0 l/s per floor-m2 in offices and 4- 6 l/s per

floor-m2 in meeting rooms in standards.

Forachievinghealthy,comfortableandenergyefficient

buildings,itisimportanttoconsidertherequired

airflowratestakenintoaccountthematerial

emissions.Indoorclimateclassificationsand

ventilationratesarespecifiedinEuropeanStandard

EN15251.Whenmaterialemissionsarelow,the

airflowratesinofficeroomsare1.5–2.0l/sper

floor-m2andinmeetingroom4-6l/sperfloor-m2.

Usingnon-lowpollutingmaterialinofficesincreases

significantlytherequiredairflowrates.Table4

presentsairflowratesaccordingtoEN15251.

Table 4. Ventilation rates in offices according European Standard EN 15251.

Ventilation rate of Occupancy Ventilation rate of Building Materials

Very low polluting Low polluting Non-low polluting

Building typeFloor aream2/p

Occupancyl/s/m2

Materiall/s/m2

Total Materiall/s/m2

Total Materiall/s/m2

Total

Cellular office I 10 1.0 0.5 1.5 1.0 2.0 2.0 3.0

II 10 0.7 0.3 1.0 0.7 1.4 1.4 2.1

III 10 0.4 0.2 0.6 0.4 0.8 0.8 1.2

Landscape office I 15 0.7 0.5 1.2 1.0 1.7 2.0 2.7

II 15 0.5 0.3 0.8 0.7 1.2 1.4 1.9

III 15 0.3 0.2 0.5 0.4 0.7 0.8 1.1

Conference room I 2 5 0.5 5.5 1.0 6.0 2.0 7.0

II 2 3.5 0.3 3.8 0.7 4.2 1.4 4.9

III 2 2 0.2 2.2 0.4 2.4 0.8 2.8

Room level

InEuropeEN15251isnowusedbymanycountries

butseveralcountriesdohavetheirownstandardsand

buildingcodes.Also,buildingclassificationschemes

requireshigherairflowratesthanstandardspecifyto

reachmaximumscoresintheevaluation.

EN15251andISOEN7730givestargetvaluesfor

thermalcomfortforboththewholebodythermal

sensationandlocalthermaldiscomforte.g.draught.

Table5onpage10showsthreecategoriesofthermal

environment.

Inheatingmode,thetemperaturegradientbetween

floorandceilingcan’tbetoohigh.Table6shows(see

page10),thereisshownthecategoriesoflocal

thermaldiscomfortparameters(verticaltemperature

gradient,floortemperatureandradianttemperature

asymmetry).

Duetoindividualvariationofthephysiologicaland

psychologicalconditions,itisdifficulttoensurean

environmentsatisfyingalloccupantsexposedtothe

samethermalenvironment.Experimentaldatashow

thatacertainamountofpersonsisalwaysdissatisfied

withthethermalconditions.

2.1Requirementsfordesignofindoorenvironmentandcoolingdemand

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Duringdesignphase,itisimportanttoanalyzeair

velocitiesintheoccupiedzonesandthusmakesure

thattheselectedsolutiondoesnotcausedraught.

WithHaltonHIT,itiseasytocarryouttherequiredair

velocitycalculations.

Indemandingcases,itisrecommendedtouseCFD-

analysisandmock-upstoguaranteetheperformance.

HaltonprovidesCFDandmock-upservicestoanalyze

theperformance.

Cooling demand

The actual cooling demands should be computed

with dynamic energy simulation program. When

the room units are selected, it is important to make

a difference beintween sensible cooling and total

cooling loads. Chilled beams are sized by sensible

cooling demand. Windows are playing a significant

role in cooling demand. It is profitable to use solar

shading or window with low g-values. Nowadays

with good solar shading and energy efficient lights,

it is possible to reach 60-80 W/floor-m2 also on

perimeter spaces.

Theenergyconsumptionofabuildingdependsonthe

qualitiesofbuildingenvelopeandtheenergyefficiency

oftheselectedHVAC-system.Thepropertiesofthe

windowsarethemostsignificantfactoroncooling

demandinmodernoffices,whereenergyefficient

lightfittingsandlaptopcomputersareenabled.

Withgoodsolarshading,thecoolingrequirementcan

besignificantlyreduced.Thereductionofcoolingloads

alsoexpandsthevarietyofHVAC-systems,whichcan

beusedinbuildings.Lowtemperatureheatingand

hightemperaturecoolingair-watersystemscanbe

moreeasilyintroducedinsuchbuildingswhere

efficientsolarshadingisintroduced.

Duringthedesignphase,itisimportanttomakea

differencebetweensensiblecoolingandtotalcooling

loads,whenair-watersystemsareconsidered.Inair-

waterroomairconditioningsystems,onlysensible

coolingloadiscoveredwithroomunits.Thelatent

loadiscompensatedinair-handlingunitby

dehumidifyingthesupplyairflowtorequiredlevelto

avoidcondensationintheroomspace.Thus,the

coolingcapacityismuchlowercomparedtoe.g.

condensingfan-coilunits,wherethemajorpartof

dehumidificationoccursinthefan-coilunitintheroom

spaces.

Room level

CategoryThermal state of the body as a whole

Operative temperature °C Max. mean air velocity m/s

PPD % PMVSummer (0,5 clo) Cooling

Winter (1 clo) Heating

Summer (0,5 clo) Cooling

Winter (1 clo) Heating

A < 6 -0.2 < PMV < + 0.2 23,5 – 25,5 21,0 – 23,0 0,18 0,15

B < 10 -0.5 < PMV < + 0.5 23,0 – 26,0 20,0 – 24,0 0,22 0,18

C < 15 0.7 < PMV < + 0.7 22,0 – 27,0 19,0 – 25,0 0,25 0,21

CategoryVertical air temperature difference K

Floor surface temperature °C

Radiant temperature asymmetry K

Warm ceiling Cool ceiling Cool wall Warm wall

A < 2 19 - 29 < 5 < 14 < 10 < 23

B < 3 19 - 29 < 5 < 14 < 10 < 23

C < 4 17 - 31 < 7 < 18 < 13 < 35

Table 5. Three categories of thermal environment.

Table 6. Recommended categories for local thermal discomfort parameters.

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Room level

Whenanairconditioningsystemissized,itis

importanttocalculatetheactualcoolingdemandby

usingdynamicenergysimulationprogram.Iftheeffect

ofthethermalmassisnottakenintoaccount,the

wholesystemisover-sized.Inthecoolingdemand,

windowpropertiesareplayingasignificantrole.If

thereisnosolarshadingorwindowwithbadsolar

heatgaincoefficient(gvalue),therequiredcooling

capacitycaneasilybe1.4-1.6timeshigherthanwith

lowsolartransferwindows.

Thecoolinganalysisoftheeffectofwindowstructure

wascarriedoutindifferentclimatezonesinEurope.

Case-study: envelope and windowThesimulatedofficeroomareawas10.8m2 (4.0x2.7x3m,LxWxH).U-valueofthewindowwas1.1W/m2Kandgvaluewas0.4.Fourdifferentheightsofwindow.U-valueoftheexternalwallwas0.3W/m2K.Theexteriorwallwasaconcretewall(heavy)andinteriorwallswereplasterboardstructures(light).

Case-study: heat gains and schedulesTwooccupants,lighting10W/floor-m2 and appliance load10W/floor-m2werefrom9.00a.m.to6.00p.mFansoperatefrom7.00a.m.to8.00p.m.providingaconstantoutdoorairflowrateof2l/s,floor-m2

Roomairtemperaturesetpointwas24°Candsupplyairtemperaturewas14°C.

Inthecase-study,thecoilcapacitywasthemostsignificantportioninthecoolingcapacitiesoftheofficerooms.Thesensiblecoolingofthechilledbeam

Fig 3. Office building module with four different window heights.

Fig.4. A case study of the required sensible cooling capacity of south and west offices in some European cities with different window heights.

coilwas60-75%oftheofficeroom.Themaximumsensiblecoolingpowerinsouthroomsvariedbetween80to120W/floor-m2.Byreducingthewindowheightto1.6m,itispossiblemaintainthesetroomairtemperatureusingthecoolingpowerof80W/floor-m2.Intotheeastandwestfacingofficerooms,themaximumcoolingcapacitywas120W/floor-m2.Whenthewindowheightwas1.6mand1.2m,therequiredcoolingcapacityreducedto90W/floor-m2 and 80W/floor-m2

1,2m 1,6m 2m 2,8m 1,2m 1,6m 2m 2,8m 1,2m 1,6m 2m 2,8mHelsinki Paris Rome

0,0

20,0

40,0

60,0

80,0

100,0

120,0

140,0

160,0

180,0

200,0

West  Office    Cooling  load  from  air  flowsCooling  load  from  beams

Coo

ling  

pow

er  (W

/m2)

1,2m 1,6m 2m 2,8m 1,2m 1,6m 2m 2,8m 1,2m 1,6m 2m 2,8mHelsinki Paris Rome

0,0

20,0

40,0

60,0

80,0

100,0

120,0

140,0

160,0

180,0

South  Office  Cooling  load  from  air  flowsCooling  load  from  beams

Coo

ling  

pow

er  (W

/m2)

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2.2Air-watersystem

2.2.1 Operation

In Halton Vario, air temperature for a beam system is

normally room air by varying the water flow rate. The

control of air quality is based on variable airflow rate.

The delivered outdoor air flow rate is adjusted to

maintain the required zone CO2 concentration. Air

flow rate adjustment could happen in three modes:

unoccupied, occupied and boost. Thanks to the

constant pressure ductwork and linearized

performance of Halton Vario control damper, airflow

rate is easy to adjust and measure. Halton Vario

makes possible to control outdoor airflow rate within

wide range and also guarantee ideal throw pattern

and draught-free operation.

Room air temperature

Thecontrolofspaceairtemperatureforabeamsystem

isnormallyaccomplishedbyvaryingthewaterflowrate

whilemaintainingaconstantoutdoorairflowrate

temperatureorsetaccordingtotheseason.Traditionally,

outdoorairflowratehasbeenconstant,butnowwith

HaltonVariosystem,airflowrateisalsopossibleto

controldemand-based.Intradionalsystemswhenthe

constantsupplyairtemperatureisusede.g.inmeeting

roomsandoffices,unoccupiedspacescouldbeover

cooledwithoutdoorairevenwhenwatervalveisclosed.

WithHaltonVarion,overcoolingisnothappening

becauseairflowrateisdemand-basedcontrolled.

InFig.5,thereisillustratedroomairtemperaturecontrol

basedon4-pipeconnectionchilledbeams.Controlofthe

watersideisaclosedloopcontrolsysteminwhichthe

roomtemperatureisthecontrolledvariable,andthechilled

orwarmwaterflowisadjustedbythecontrolvalve

installedaspartofthewaterpipingtothebeamsinthe

space.Betweenheatingandcoolingmodes,thecontroller

operatesonzero-energybandandbothheatingand

coolingvalvesareclosed.

Thecontrolvalvecanoperateeitherastwo-position

(on-off)ormodulating.On-offcontrolmaycause

significantfluctuationsinthedeliveredairtemperatureof

activebeams,leadingtoswingsinroomconditions.

Whenapplyingconventionalmodulatingcontrolvalves

caremustbetakentoadequatelyselectthevalvesso

thattheyhaveenoughauthorityinthehydrauliccircuit.

Whenmodulatingpressureindependentcontrolvalves

areappliedthevalvesalwayshavefullauthority,the

selectionofthecontrolvalvebecomesmoresimple,not

Room level

12 13

Fig.5. Room air temperature control sequences with Halton 4-pipe Vario system's chilled beam.

Room level

requiringauthorityverificationandanexcellentqualityof

theroomtemperaturecontrolcanmoreeasilybe

achieved.

Roomairtemperaturesetpointcanbedifferentfor

heatingandcoolingmodesandcanbevariedalsobased

ontheroomoccupancymode.Thisadaptsroomair

temperatureaccordingtooutdoorconditionsandsaves

energyonstand-byandunoccupiedmodes.

Table 7. Examples of room air temperature set points.

Space mode Heating mode Cooling mode

Occupied 20 °C 25 °C

Stand-by 19 °C 26 °C

Unoccupied 18 °C 28 °C

InTable7,thereispresentedtypicalroomairtemperature

setpoints.Allpresentedvaluesareparametersthatuser

canchange.

Usercanchangetheroomairtemperaturesetpointwith

wallmountedorremoteuserpanel.Thesetpointshift

rangeisdefinedasparameter.Thedefaultvalueofthe

shiftis±3°C.

Severaldifferentroomairtemperaturecontrolsequences

canbechosenbycontrollerconfiguration(Fig.6):

•2-pipeapplicationforcoolingonly

•2pipeapplicationusingchange-overcontrolforcooling

orheating

•4-pipeapplicationforcoolingandheating

•2pipeapplicationforcoolingandelectricheating

•2pipeapplicationusingchange-overforcoolingand

heatingandadditionalelectricheatingelementfor

reheat

Fig.6. Control sequences of heating and cooling.

• 2-pipe with electric heating, water heating or cooling change over

• 2-pipe, heating or cooling change over

• 4-pipe, heating and cooling

• 2-pipe with electric heating, water cooling

• 2-pipe, heating sequence only

• 2-pipe, cooling only

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Room level

Fig.8. Airflow rate is controlled based on occupancy and air quality sensors.

Theairqualitycontrolsequencecanbeusedalsoas

extracoolingbyprovidingextraoutdoorairintothe

space.Theincreasedoutdoorairflow

ratecanbeusedasaprimaryofsecondarycooling

sequence(Fig.7).

Air quality

Airqualityiscontrolledbasedonroomoccupancy

modeandroomconditions.Thecontrolofairqualityis

basedonvariableairflowrate.Inoffices,airflowrateis

typicallyadjustedaccordingtooccupancyofthe

space.Inmeetingrooms,additionalairflowrateis

providedbasedonoccupancyandairquality.

ControlofairqualityisbasedonCO2sensor.Demand

controlventilationinvolvesvaryingtheoutdoorairflow

rateinresponsetothequantityofoccupantsinthe

space.Typically,sensorsmonitortheCO2levelsanda

roomspacecontrollermeasuresthedeliveredoutdoor

airflowratetomaintaintherequiredzoneCO2

concentration.Intheroomcontrolsystem,therecould

beintegratede.g.windowswitchandcondensation

sensortopreventcondensation.Thoseswitchesand

sensorsstopstopwaterflowratewhenthereisarisk

ofcondensation.

Inmeetingrooms,airflowisadjustedfromminimum

tomaximum(e.g.from10to100%).Inmeetingroom,

therearethreemodes:unoccupied,occupiedand

boost.Inofficestheairflowisadjustedaccordingto

occupancyofthespace.Inoffices,therearetwo

Fig 7. Air flow rate configured as second or first control sequence.

Air flow rate configured as second cooling sequence. Air flow rate configured as first cooling sequence.

14 15

Room level

modes:unoccupiedandoccupied.Fig.8illustrates

demandcontrolventilationwithHaltonVariosystem's

beams.

BMSsystemadjuststothesystemeithernightorday

operationmode.Inunoccupiedspaces,there

couldbedifferentairflowratesettingfornightandday

times.

InTable8,thereareshownoperationmodesand

airflowcontrolfunctionsinunoccupiedandoccupied

spacesduringdayandnighttimes.

TheactualHaltonVariosystem'schilledbeamairflow

ratedependsontheselectedbeamtype(lengthand

Table 8. Operation modes and the control of airflow rate.

BMS Room CO2 Operation modes and airflow rate control

> 400 ppm Boost Increased airflow Increased airflow based on room conditions

Occupied Normal airflow Normal Halton Rex beam airflow

Stand-by Reduced airflow Adjustable by parameter

Unoccupied Eco settings Adjustable by parameter, or off

Occupied Normal settings Normal Halton Rex beam airflow

nozzlesize),levelofstaticpressureinductworkand

controllerparametersettings.Thenormaland

maximumairflowcanbeselectedfromHaltonHIT.

Intheunoccupiedandstand-bymodes,theHalton

Rexbeamairflowisreducedandthereforeheatingor

coolingcapacityoftheroomunitisdecreased.To

preventspacetemperatureexceedingtemperature

setting,thecontrollerwillresettheunitairflowrateto

normalairflowvalueuntilroomconditionsareagainon

thedesiredlevel.Whentheroomairtemperaturehas

reachedthesetpoint,theairflowrateisthen

readjustedtotheunoccupiedandstand-bysettings.

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Room level

Throw pattern

InHaltonVariosystem,airflowrateiscontrolledin3

steps.Inunoccupiedmode(step1),airflowrateis

minimale.g.0.3l/sperm2.Whentheoccupancy

sensorrealizesthatthespaceisoccupied,airflowrate

settovaluebasedonthestandarde.g.1.5–2l/sper

m2(step2).Airflowrateisboostedandmodulated

whenairqualitysensordemandsmoreoutdoorair

(step3).InFig.9,thereispresentedthethrown

patterninthreedifferentoperationmodes.

InHaltonRexchilledbeamdual-chamberstructure,

airflowrateisreleasedtoroomspacefromtwonozzle

rows(Fig.10).Thisconceptmakespossibletocontrol

outdoorairflowratewithinwiderangeandalso

guaranteeidealthrowpatternanddraught-freeoperation.

Thankstotheconstantpressureductworkand

linearizedperformanceofHaltonVariosystem's

controldamper,airflowrateiseasytoadjustand

measureusingproductdata.Aprincipleofthecontrol

strategyisshowninFig.11:inunoccupiedmode,the

minimumairflow5l/srateisadjustedwiththecontrol

signalof0.7V.Withthecontrolsignalof5V,the

airflowrateissettobe20l/sthatisrequiredinthe

occupiedmode.Bythechangingthecontrolsignal

from5Vto10V,airflowrateismodulatedfrom20l/s

to75l/s.

Fig.9. Thrown pattern in unoccupied, occupied and boosts modes.

Fig.10. Air is released from two nozzle rows in Halton Vario concept.

Fig.11. A principle of the correlation between control signal and the outdoor airflow rate in Halton Vario system.

Itshouldbenotedthatwhentheoutdoorairflowrate

isincreased,theamountoftheinducedairthrough

thewatercoilalsoincreased.Thuswithhighoutdoor

airflowrates,thereispossible,ifneeded,toincrease

coolingcapacityfromwaterside.

0 1 2 3 4 5 6 7 8 9 100

10

20

30

40

50

60

70

80

90

Control signal V (DC)

l/s l/s

Control signal V (DC)

16 17

2.2.2 Layout and control zone considerations

Chilled beam layout selection takes into account room module dimensions, intended use of the space and flexibility requirements. Beams installation could be in parallel or perpendicular to the façade. Zone control covers room air temperature, outdoor airflow rate and exhaust airflow rate control schemes. The floor area of the single control zone should not be more than 50 m2. This means that the space controller is the master for 1-4 room units.

Thelayouthassomeinfluenceonthehorizontalairdischargeinthespaceandshouldthusbetakenintoaccountatthedesignstage.Asthrownpatterndependsontheroomormoduledimensions,intendeduse,andflexibilityrequired.

Oneofthefirstconsiderationsisarchitecturalrequirementsandowner’swishesforflexibility,Whetheractivebeamscanbearrangedinparallelorperpendiculartothefaçadeprimarilydependsontheapplication.

Itisrecommendedtouseperpendicularinstallation(Fig.12).Inperpendicularinstallation,thermalplumeofwindowhaslowerinfluenceonairdistributionthanwithparallelinstallation(Fig.13).Whenactivebeamsareinstalledparalleltothefaçadetheirairdischargestowardstheexteriorwallandtheinternalzone.Duringwintertime,thedischargetowardsthecoldfaçadeleadshigherdraughtrisk.Withgoodqualitywindowsand solar protection difference between two types of installationsbecomesneglectable.

Room level

Fig.12. Installation of active beams perpendicular to the façade.

Fig.13. Installation of active beams parallel to the façade.

18

Room level

Inperpendicularinstallationtypically,thelengthofthebeamisfrom2.7mto4m.Tosuitarchitecturalrequirements,thelengthofthebeamcasingcanbeselectedlongerthantheactualcapacityrequires(e.g.aslongastheroom).Inthiscasethecoilissizedaccordingtotherequiredcoolingload.Thedistancebetweenthebeamrowsareselectedbasedontheselectedmodulesizeandtoguaranteedraught-freeairdistribution.Typicaldistancebetweentherowsisfrom2.5mto4m.

Inparallelinstallation,thebeamlengthisselectedtofitwiththeroommodulesandflexibledemands.Typically,thelengthofthebeamisbetween1.2m-4.0m.Dependingonthemodulesize,therecouldbeoneortwobeamrowsinthemodule.

Selectionofcontrolzone,itisalwaysbalancingofflexibility(futurechurncosts)andfirstcost.Naturally,smallcontrolzoneenableshighflexibilityandonthecontraryincreasesfirstcosts.

Somecasesitmakessensetoutilizedifferentbeamlengthsandtobuilddemand-basedsizeofthecontrolzones.InFig.15,thereisshownanexampleof

differentsizesofthecontrolzonesinanopenlayoutoffice.In7.5mx16mmodule,5differentzonesaredesigned(redlines).Themarkedredlinesarepre-designedlocationsofwalls.Thatisaccomplishedwith2beamlengths(1.2mand2.4m)installedin5rows.

Zonecontrolcoversroomairtemperature,outdoorairflowrateandexhaustairflowratecontrolschemes.Controlzonecouldbearoomorseveralroomunitscouldbecontrolledparallel.Inpractice,theareaofthecontrolzoneshouldnotbemorethan50m2 to maintaingoodcontrollabilityofinternalconditionsinopenlayoutoffice.

InFig.16,thereisshownofanexampleofthecontrolzoneselectionswhereone(~10m2)andfive(~50m2)roomunitsconsistsacontrolzone.Inthecontrolzoneoffiveroomunitsandacommonroomcontroller,theroomairtemperaturehappenswithacommonvalveorallbeamsareequippedwithvalvesandthosevalvesareparallelcontrolled.

Infiveroomunitszone,indoorairqualityiscontrolledwiththeroomunitspecificcontroldampers.Thosedampersarecontrolledindividuallyorparallelusingoneorseveraloccupancysensor.

2.2.3 System & component overviewTheHaltonVariosystemcontrollerisaroomcontrollerdedicatedtocompleteroomapplicationsprovidingthecontrolofcooling,heating,demandcontrolledventilation.TheHaltonVariosystem'sroomcontrollermanageschilledbeamoperationbycontrollingchilledwaterandhotwatercontrolvalvesin2-or4-pipeapplications.Alsoelectricheatingcanbeused.

Thesystemcanoperateasstandaloneorconnectedtoabussystem.

InHaltonVariosystem,theroomcontrolpackagecoversallrequiredsensor,actuators,valvesanddampersthatmakespossibletocontrolroomairtemperatureandindoorairquality.InFig.17,thereisdescribedthepossibleoptionstointegrateforroomcontrolscheme.RoomcontrollerandsensorcouldbefactoryinstalledintoHaltonRexchilledbeamunit.

Fig.15. Utilization of two beam lengths makes it possible to build different sizes of the control zones. All read lines are the boundaries of the control zones. Control zones are equipped with enough number of occupancy sensors. Typically one occupancy sensor cover ~15 m2.

needsamodifiedimage*nowtoo

unclear

18 19

Fig.16. An example of the selection of control zones where the dotted lines indicate the boundaries of the selected zones.

Fig.17. Components for the room controller.

Room level

11

Wall control panel

Cooling valve

Heating valve

Unit integrated temperature sensor

Window switch

Condense sensor

Room controller

Multi-sensor

CO2 sensor

Remote control panel

Halton Rex Vario 600 with airflow control damper

•HaltonRexintegratedroomcontroller

•Roomairtemperaturemeasurementto

controlspacetemperature

•Occupancysensorfordemandbased

operationwithairflowratecontrol

damper

•Airqualitycontrolwithcarbondioxide

sensor,CO2

•Coolingwithchilledwatercontrolvalve

•Heatingwithhotwatercontrolvalveor

electricalheatingasanoption

•Severaluserinterfaceoptions,either

wallmountedorhand-heldremote

controller

•Condenseprevention

•Energysavingwindowswitch

operation

newclearerimageneededhere'

20

Room level

System components1)HaltonRexchilledbeamswithventilation,coolingandheating(waterorelectric),•Valvesandactuator•Damperandactuator

2)Roomcontroller,userinterfaceandsensors•Userinterfacepanel•Roomairtemperaturesensor•Occupancysensor•Carbondioxidesensor•Windowswitch•Condensationsensor•Lightandsunblindscontrol

Occupancysensorisafundamentalelementof

demandbasedroomconditioncontrol.Itdetects

presenceofpeopleandthereforeadjuststhespace

eithertounoccupiedoroccupiedmode.Theremote

controlleriscommunicatingwithHaltonmulti-sensor.

Themulti-sensorincludesoccupancysensor,light

sensorandremotecontrollerinterface(Fig.18).

Whenapersonenterstheroom,theoccupancy

sensorsendsasignaltotheHaltonVariosystem's

controllertoinformthatthespaceisoccupied().The

controllersetautomaticallyairflowrateandroomair

temperaturesetpointtoacomfortlevel.Whenleaving

thespacetheoccupancysensorsendsanoffsignalto

theHaltonVariosystem'scontrollerthatthespaceis

empty.Afterachosentimedelaythecontrollerwill

usethesetpointsforunoccupiedspace()sensor

coversofthespaceareaof38m2(7x5.5m).Thus,an

occupancysensorcanserve1or2chilledbeamsin

openlayoutoffice.

Thebuildingmanagementsystem(BMS)may

participateinoperatingmodedefinitionbysendingday

andnightinformation.Inthisdocumenttheday()

representsnormalofficehoursandnight()referto

timewhenmostpeopleareoutofoffice.The

combinationofoccupancysensorandBMS

informationdefinestheactualroommode(Table9)

whereallmodeshaveindividualroomairtemperature

andairflowratesettings.

Table 9. Occupancy based space operation modes.

BMS Room Operation modes and airflow rate control

Occupied Comfort settings

Stand-by Be ready for comfort, while saving energy

Unoccupied Eco settings

Occupied Comfort settings

Roomairtemperaturecanbemeasuredeitherbywall

mounteduserpanelorHaltonRexchilledbeamunit

integratedtemperaturesensor(Fig.19).Wallmounted

userpanelisthemostbeneficial,whenfeasibleceiling

structureisavailable.

Thecontrolunitintegratedtemperaturesensor

ensuresmostflexiblelayoutstructureoffloorspace.

TheHaltonRexchilledbeamcanbelocatedeitherin

openfloorspaceoratdedicatedroom.The

temperaturesensorismeasuringthetemperatureof

thespace,andcontrolstheheatingandcoolingvalves

accordingtoroomairtemperaturesetpoint.

Fig. 18. Occupancy sensor and remote controller interface.

Fig. 19. Room temperature control panel and integrated temperature sensor.

20 21

Room level

Condensesensorpreventswatercoilcondensation.In

caseofcondensationthecoolingvalvewillbeclosed

and airflow control damper is set to predefined

position(configurable:remaininnormalcontrol,closed

orfullyopen).Normalcoolingoperationwillbe

re-activatedafteradelay,whencondensationhas

vanished.

Fig. 21. Window switch to detect open window.

Fig. 20. Condense sensor.

Windowswitchisusedtodetectopenwindow.If

windowisopened,bothheatingandcoolingwillbe

closeddown(watervalvesandoptionalelectrical

heating).TheairflowcontroldamperofHaltonRex

chilledbeamissettopredefinedairflowrateposition

(configurable:previousvalue,min,medornormal).In

allcasesthefreezeprotectionmodestaysactive.The

freezeprotectionmodeisactivated,ifroomair

temperaturefallsbelow+8°C.Atfreezeprotection

theheatingvalveorelectricalheatingisactivatedto

preventwatercoilicing.Normalcontroloperation

startsafterpredefineddelaywhenthewindowis

re-closed.

Fordemandbasedventilation,CO2- concentration is

usedasanindicatorofindoorairquality.Supply

airflowrateiscontrolledtomaintainthesettarget

valueofCO2whentheoccupancyratioofpersonis

changed.ThesetvalueofCO2- sensor is typically

600-900ppm(Fig.22).

Fig. 22. Control principle of indoor air quality with CO2- sensor.

22

2.3All-airsystem

2.3.1 Operation

TheHaltonVariosystemisbasedonactivediffusers

andconstantstaticpressure.Roomairconditionsare

controlledbymodulatingsupplyairflowrate.The

controllingsensorcanbeatemperaturesensor,aCO2

sensor,apresencesensororacombinationofthese.

Thethrowpatternisconstantinalloperation

conditionsandthusdraughtriskisminimized.

Dependingonhowthechangeinthepressureofthe

zoneductismanaged,theall-airterminalunitsare

classifiedaspressureindependentorpressure

dependentunits.ApressureindependentVAV-unit

canbedefinedasadevicewheretheairflowcontrolis

notdisturbedbythefluctuationsofthestaticpressure

attheinletofthedevice.Keepingtherequiredstatic

pressureinthemainductsafter

thefansystemcancontrolterminalunits.InFig.23,

thereisshownaconceptofpressureindependent

VAV-system.

Theflowisdeterminedbasedonthedevice'sopening

(between0to100%)andtheunderlyingconstant

staticpressure.Therefore,inordertoassureproper

workofthevariableVAVdiffusers,thelevelofa

pressureintheinletsideshouldbestrictlycontrolled.

Thisisassuredwithinstallingactivecontroldampers

ontheductsservingdifferentzonesformaintaining

constantpressure.

ApressuredependentVAV-unitisadevicewherethe

airflowcontrolisdependingonthestaticpressureat

theinletsideofthedevice.Theairflowwillvarywith

thefluctuationsinstaticpressurebeforethedeviceif

thestaticpressureinthezoneductisnotmaintained

constant.HaltonVariosystem'sall-airsystemisbased

ontheconstantpressureductworkandpressure

dependingactivediffusers.InFig.24,thereisshown

aconceptofpressuredependentVAV-system.

Room level

22 23

Fig.23. A traditional VAV system with pressure independent space supply air terminal units.

Fig.24. Halton Vario all-sir system based on the constant static ductwork.

Room level

24

Room level

IntraditionalVAVsystemwithpressureindependent

supplyairterminalunits,thepressuresensorSPset

pointvalueiskeptonalevelthatcanassureaproper

workofapressureindependentVAVterminalunitatthe

designairflowrate.Inpressureindependentairterminal

unit,thepressuredropsoverthedeviceistypically30

-50Pa.

Room air temperature

Roomairconditionsarecontrolledbymodulating

supplyairflowrate.Incoolingmode,during

unoccupiedmodethesupplyairflowrateatminimum

value.Inthesequence,thesystemisstandbymode.

Whenloads/pollutionsincrease,theairflowrateis

increasedtoreachthesettargetvalue.Exhaust

followsasaslavesupplyside.Inheatingmode,the

operationisasincoolingexceptseparatesetof

parameters

Theparametersthatcontroltheamountofairsupplied

totheroomcanbetemperature,CO2 or presence in

theroom.Usercouldboostbyhandswitchtheairflow

andifwindowisopenventilationisstopped.InFig.

25,thereisshownaprincipleofthesequencesforair

temperaturecontrol.

Usercanchangetheroomairtemperaturesetpoint

withwallmountedorremoteuserpanel.Thesetpoint

shiftrangeisdefinedasparameter.Thedefaultvalue

oftheshiftis±3°C.

Air quality

Airqualityiscontrolledbasedonroomoccupancy

mod,temperatureandindoorairquality.Inoffices,

airflowrateistypicallyadjustedaccordingtoroomair

temperatureandoccupancyofthespace.Inmeeting

roomstogetherwithroomairtemperatureand

occupancy,indoorairqualityiscontrolled.

ControlofairqualityisbasedonCO2sensor.Demand

controlventilationinvolvesvaryingtheoutdoorairflow

rateinresponsetothequantityofoccupantsinthe

space.HaltondiffuserJazincreasedautomatically

supplyairflowrateandmaintainthesetCO2-level,

WhenbothroomairtemperatureandCO2- sensors

areused,thehigherdemandcontrolsthesupply

airflowrate.Fig.26illustratesdemandcontrol

ventilationwithHaltonJazactivediffuserconcept.

BMSsystemadjuststothesystemeithernightorday

operationmode.Inunoccupiedspaces,therecouldbe

differentairflowratesettingfornightanddaytimes.

InTable11,thereareshownoperationmodesand

airflowcontrolfunctionsinunoccupiedandoccupied

spacesduringdayandnighttimes.

TheactualHaltondiffuserJazairflowratesdependon

selectedactivediffusersize,levelofstaticpressurein

ductworkandcontrollerparametersettings.The

airflowrangeforthespecificconditioncanbefound

fromHaltonHIT.

Intheunoccupiedandstand-bymodes,theHalton

diffuserJazairflowisreducedandthereforeheatingor

coolingcapacityoftheroomunitisdecreased.To

preventspacetemperatureexceedingtemperature

setting,thecontrollerwillresettheunitairflowrateto

normalairflowvalueuntilroomconditionsareagainon

thedesiredlevel.Whentheroomairtemperaturehas

reachedthesetpoint,theairflowrateisthen

readjustedtotheunoccupiedandstand-bysettings.

Fig.25. Halton Vario Room air temperature control sequences with Halton Vario air terminal unit.

InTable10,thereispresentedtypicalroomair

temperaturesetpoints.Allpresentedvaluesare

parametersthatusercanchange.

Table 10. Examples of room air temperature set points.

Space mode Cooling mode

Occupied 25 °C

Stand-by 26 °C

Unoccupied 28 °C

24 25

Room level

Office room, typical airflow operation Meeting room, typical airflow operation

Fig. 26 Airflow rate is controlled based on occupancy, room air temperature and air quality.

Table 11. Operation modes and the control of airflow rate.

BMS Room CO2 Operation modes and airflow rate control

600-900 ppm Boost Increased airflow Increased airflow based on room conditions

Occupied Normal airflow Adjusted by parameter

Stand-by Reduced airflow Adjustable by parameter

Unoccupied Eco settings Adjustable by parameter, or off

Occupied Normal settings Normal diffuser airflow

Throw pattern

ThedraughtriskmayoccurwhenusingVAVterminal

unitstogetherwithsupplyairdiffuserswithconstant

dischargearea,suchasCAVsupplyairdevices.The

airflowpatternissuingfromthediffuser,which

dischargestheairhorizontallyacrosstheceiling,hasa

naturaltendencytoattachtothesurface.Ifthe

dischargeareaofthediffuserremainsconstant,the

velocityofthesupplyairstreamfallsindirect

proportiontothereducedairflowrate,resultingarisk

ofthesupplyairjetfallingawayfromtheceiling.

HaltonJazall-airactivediffusercontrolsthrowpattern

andthuspreventdraughtrisk.Draughtriskhasbeen

avoidedwithactivediffuserwork,whichcontrolsthe

diffuseropeningsinawaythatrelativelyconstantair

velocityrangeismaintainedanddumpingwillbe

avoided.ThethrowpatternofHaltonJazactive

diffuserwithmaximumandminimumairflowrateis

illustratedinFig.27.

Fig.27. A scheme of the thrown patter of Halton Vario active diffuser.

Halton Jaz Vario maintains thermal conditions

•Withlowairflowrates,thethrowpatternisdetached

fromceiling:Coanda-effectisutilizedevenwhen

airflowratesareattheminimumlevel

•Demand-basedairflowratesavesenergy.

InHaltonactivediffuser,theairflowcontrolandroom

airdistributioncomponentsareintegratedintothe

sameterminalunit.Thenumberofrequiredsystem

componentsisreducedcomparedstandardVAV-

system.

Min. flow 10%

Max. flow 100%

Min. flow 10%

Max. flow 100%

26

Fig. 28. A principle of the operation of Halton Jaz active diffuser.

Activediffuserchangesitsoutletconfiguration

automaticallywhencontrollingthesuppliedairflow

rate.Theairissuppliedbetweenacontrollingplate

withadistancethatvariesaccordingtotheairflow

rateneeded(Fig.28).Thepositionoftheplateis

controlledbyatraversingmotor,whichgetsimpulses

fromthecontrollingsensorlocatingintheroom.The

controllingsensorcanbeatemperaturesensor,aCO2

sensor,apresencesensororacombinationofthese.

Theflowisdeterminedbasedonthediffuser's

opening,whichisbetween0to100%andthe

underlyingconstantstaticpressure.

Thebasicideabehindthevariablesupplyairdiffuseris

tomaintainaconstantvelocityofthesupplyair

streamdischargedfromthediffuserwithadecreasing

supplyairflowrate.

Room level

2.3.2 Layout and control zone considerations

Zonecontrolcoversroomairtemperature,outdoor

airflowrateandexhaustairflowratecontrolschemes.

Thefloorareaofthecontrolzoneshouldnotbemore

than50m2.Thenumberofparallelcontrolledunits

shouldnotbemorethanfive.

Abalancebetweenthesupplyandexhaustairshould

beassuredinalloperationconditions.Thebalance

betweensupplyandexhaustsideiscontrolledatzone

level.Basedonthesupplyairflowratemeasurement,

theexhaustairflowrateissettomaintaintherequired

pressurizationorequalflowsinsupplyandexhaust

sides.Balancedcontrolzonecouldbearoomor

severalroomunitscouldformacontrolzone.

Inzoneswhereisseveralsupplyunits,theairflowrate

oftheeachunitsarecontrolledparallel.Thenumberof

theparallelcontrolunitshouldnotbehigherthan4

andthemaximumsizeofthecontrolzoneshouldnot

belargerthan50m2.

Exhaustairflowratecouldbeductedineachzone.

Exhaustductworkispossiblesimplifiedbyonly

providingsupplyairflowrateinthespaces.Becauseof

over-pressuretosurroundings,exhaustisleadedto

corridorandfurthertowardscentralizedexhaust

system.Inrooms,thereareinstalledtransfergrilles.

Thetransfergrillesshouldhaverequiredattenuation

propertytomaintainacousticsprivacyInthespaces.

InFig.29,thereisshownanexampleofHaltonJaz

all-airconceptwherethesupplyandexhaustairflow

ratesarebalancedatzonelevel.InFig.30,thereisan

exampleofonefloorofopenlayoutofficewherethe

exhaustiscentralized.

Itshouldbenotedthatinthecentralizedexhaust

conceptairflowratebalanceisnotreallyfulfilledin

eachrooms.Thebalancebetweensupplyandexhaust

airflowratesisvalidonlyatzonelevel.

Tomaintainexactspacelevelairflowratebalance

betweensupplyandexhaustairflowrates,exhaust

sideshouldbeprovidedcontroldamper.Supplyair

flowrateisthemasterandexhaustairflowrateisthe

slavethatfollowssupplyairflowrateandmaintainthe

setpressurization.Toprovideinbothsupplyand

exhaustdemand-basedcontrol,theinvestmentcosts

ishigherthanwithcentralizedexhaustsystem.

26 27

Fig.29 An example of the selection of control zones with Halton Jaz system.

Room level

Fig.30. An example of installation in open layout office with Halton Jaz diffuser.

'needanewclearerimagewithout

theredtext*

28

Room level

System & component overview

TheHaltonVariosystem'sJazcontrollerisaroom

controller dedicated to complete room applications

providingthecontrolofcoolinganddemandcontrolled

ventilation.InFig.31,thereisdescribedthepossible

optionstointegrateforroomcontrolscheme.Room

controllerandsensorcouldbefactoryinstalledinto

HaltonJazactivediffuser.

Thesystemcanoperateasstandaloneorconnected

toabussystem.

InHaltonVariosystemJazdiffuser,theroomcontrol

packagecoversallrequiredsensor,actuatorsand

dampersthatmakespossibletocontrolroomair

temperatureincoolingmodeandindoorairquality.

System components

1)HaltonVariosystemJazactivediffuserforcooling

andventilation,

•embeddedtravelsingactuarandcontrolplate

2)Roomcontroller,userinterfaceandsensors

•Userinterfacepanel

•Roomairtemperaturesensor

•Occupancysensor

•Carbondioxidesensor

•Windowswitch

•Lightandsunblindscontrol

Occupancysensorisafundamentalelementof

demandbasedroomconditioncontrol.Itdetects

presenceofpeopleandthereforeadjuststhespace

eithertocomfortorenergysavingmode.Theremote

controlleriscommunicatingwithHaltonmulti-sensor.

Themulti-sensorincludesoccupancysensor,light

sensorandremotecontrollerinterface(Fig.32).One

sensorcouldcoverof15m2floorarea.

Whenapersonenterstheroom,theoccupancysensorsendsasignaltotheHaltonVariosystem's

Fig. 31. Components for the room controller. 15

Wall control panel

Room controller

Multi-sensor

CO2 sensor

Remote control panel

Unit integrated temperature sensor

Window switch

Halton Jaz Vario active diffuser with airflow control damper

•HaltonJazdiffuserintegratedroom

controller

•Roomairtemperaturemeasurementto

controlspacetemperature

•Occupancysensorfordemandbased

operationwithJazairflowcontrol,

installedonsuspendedceiling

•Airqualitycontrolwithcarbondioxide

sensor,CO2

•CoolingwithJazairflowcontrol

•Severaluserinterfaceoptions,either

wallmountedorhand-heldremote

controller

•Energysavingwindowswitch

operation

Fig. 32. Occupancy sensor and remote controller interface.

28 29

Room level

controllertoinformthatthespaceisoccupied().Thecontrollersetautomaticallyairflowrateandroomairtemperaturesetpointtoacomfortlevel.WhenleavingthespacetheoccupancysensorsendsanoffsignaltotheHaltonVariosystem'scontrollerthatthespaceisempty.Afterachosentimedelaythecontrollerwillusethesetpointsforunoccupiedspace()andadjustthespaceintoecomode.Theoccupancysensorcoversofthespaceareaof38m2(7x5.5m).Thus,anoccupancysensorcanserve1or2Jazactivediffusersinopenlayoutoffice.

Thebuildingmanagementsystem(BMS)mayparticipateinoperatingmodedefinitionbysendingdayandnightinformation.Inthisdocumenttheday()representsnormalofficehoursandnight()refertotimewhenmostpeopleareoutofoffice.ThecombinationofoccupancysensorandBMSinformationdefinestheactualroommode(Table12)whereallmodeshaveindividualroomairtemperatureandairflowratesettings.

Fig. 33. Room temperature control panel and integrated temperature sensor.

Fig. 35. Window switch to detect open window.

Table 12. Occupancy based space operation modes.

BMS Room Operation modes and airflow rate control

Occupied Comfort settings

Stand-by Be ready for comfort, while saving energy

Unoccupied Eco settings

Occupied Comfort settings

Fig. 36. Control principle of indoor air quality with CO2- sensor.

Windowswitchisusedtodetectopenwindow(Fig.35).Ifwindowisopened,coolingwithsupplyairwillbestopped.ThetraversingmotorofHaltonVariosystem'sJazdiffuserissettopredefinedairflowrateposition).

Fordemandbasedventilation,CO2- concentration is usedasanindicatorofindoorairquality.SupplyairflowrateiscontrolledtomaintainthesettargetvalueofCO2whentheoccupancyratioofpersonischanged.ThesetvalueofCO2-sensoristypically400-500ppm(Fig.36).

Fig. 34. Perforated and solid bottom plate option for Halton Jaz Halton Vario system's units.

RoomairtemperaturecanbemeasuredeitherbywallmounteduserpanelorHaltonJazdiffuserunitintegratedtemperaturesensor(Fig.33).Wallmounteduserpanelisthemostbeneficial,whenfeasibleceilingstructureisavailable.

Thecontrolunitintegratedtemperaturesensorensuresmostflexiblelayoutstructureoffloorspace.TheHaltonJazdiffusercanbelocatedeitherinopenfloorspaceoratdedicatedroom.Thetemperaturesensorismeasuringthetemperatureofthespace,andcontrolstheheatingandcoolingvalvesaccordingtoroomairtemperaturesetpoint.

TemperatureandCO2-sensorscanbeintegratedintoperforatedsupplyofHaltonJazdiffuserunits.Sensorintegrationisavailableforsolidandperforatebottomplateexhaustunits.Alternativelywallmounteduserpanelwhereroomtemperaturesensorisinstalledcouldbeused.InFig.34,thereispresentedtwoavailablebottomplatesoption.

30

Zonal level

The constant static pressure ductwork guarantees the performance of the demand- based room terminals. Balancing and monitoring of space airflow rate is simple thanks the linear function of the space damper. In the same zone, it is possible to integrate constant and variable airflow rate terminal units.

Thepurposeofsupplyductworkistodeliverairfromthefantotheroomterminalswhichdistributeairtotheroom.Therequiredpressuredifferentialrequiredbythefanisafunctionofductdesign.Theobjectiveofductdesignistosizetheductsuchthat: •Enableeasychangeofairflowratesofspaces •Minimizepressuredrop •Minimizenoise •Minimizedcost •SimplifyBalancing

Properductdesignrequiredknowledgeofthefactorsthataffectpressuredropandvelocityintheduct.

3.Zonallevel

Pressureinaductsystemisthesumoftwocomponents,staticpressureandvelocitypressure.Staticpressureisequalinalldirections.Velocitypressure(dynamicpressure)isduetothemomentumoftheair.Velocitypressureisdirectional.DynamicpressurecanbecalculatedusingEquation1wherevisairvelocityandρ=densityofair(1.2kg/m3).

Pdyn = ½*ρ*v2 (1)D

Dynamicpressureplusstaticpressure(Ps)isequaltototalpressureasshowninEquation2.

Pt=Pdyn+Ps (2)

Iftheoutletareaislargerthantheinletarea,thevelocitypressureattheoutletmustdecrease.Withafrictionlesssystemwheretotalpressureremainsconstant(Pt),staticpressure(Ps)mustincreaseatthesameratethatvelocitypressure(Pdyn)decreases.Thisphenomenonisknownasstaticregain.Inconstantpressureductworkconceptthisstaticregainisutilized.

3.1Operationbasedonconstantpressureductwork

30 31

Fig. 37. Development of the static, dynamic and total pressure in a ductwork.

Zonal level

However,bothductworkandfittingsintroducefriction.Instraightduct,frictionlossesareduetofluidviscosity.Frictionlossesoffittingsarecausedbyturbulencebetweenthemainandbranchductswhentheairflowpathdirectionchange.Frictionlossesareirreversibleandaretheconversionofmechanicalenergyintoheat.

Generallyspeaking,frictionlossesperunitlengthofstraightductarelessseverethanfrictionlossesinfittings.Frictionallossesoccurattheexpenseofstaticpressure.Frictionallossesdonotimpactvelocitypressure.InFig.37,thereisshowndevelopmentofthetotal,dynamicandstaticpressureinaductworkfromtheairintaketotheterminalunit.

Thesumofthestaticpressureplusdynamicpressureatanypointequalsthetotalpressureintheductsystem.Thelossintotalpressureisadirectresultofthelossinstaticpressureduetofrictionalandturbulencelosses.

Mostengineersusetheequalfrictionlossmethodinductworkdesign.Typicaldesignvalueofthefrictionlossis0.5-1Paperlinearmeter.Withtheequalfrictionlossmethod,thisleadstoairvelocityof4...6m/s.Thismethodisforcingthedesignertoconstantlydecreasethefreeareaoftheduct.InFig.38,thereisdescribedthetotal,dynamicandstaticpressureswhentheconstantpressurelossmethodisused.

Withtheconstantstaticpressuremethod,thepressurelossofductbranchisregainedbydecreasingtheairvelocityafterthebranch.Thishappenswhentheductisnotreduced.Thesamesizeofductworkandrelativelylowvelocity(<max3..5m/s)guaranteesinpracticethatthestaticpressureoverthezoneisconstant.

32

Zonal level

Fig. 38. The change of the total, dynamic and static pressures with constant friction loss method.

Fig. 39. The change of the total, dynamic and static pressures with constant static pressure method.

Thebenefitsofthestaticpressureductworkare:•Giveflexibilitytocontrolspaceairflowrateswith

linear control dampers•Toensureoptimalpressurelevelinallductbranches•Possibletointegrateconstantairflowrate(CAV)and

variableairflowrate(VAV)unitsinthesameductwork

•Easybalancing:onlystaticpressureshouldbechecked

•Reducednoisegenerationinductworkbecauseoflowvelocities

•Lowerfanpowercomparedequalfrictiondesignbecauseoflowvelocities

•Enablesfanoptimizationbyoptimizationdamperpositionsfortherequiredzonalstaticpressure

Inasimplifiedcase-ductwork(Fig.40),thereisdemonstratedthedifferenceofthepressurelevelsbetweentheequalfrictionlossandconstantstaticpressuremethods.Bymaintainingtheconstantfrictionloss(constantairvelocity),thestaticpressurereducesalotovertheductzone.Inthiscase-duct,thestaticpressureisatthefirstterminalunit110Paandreducedto30Paattheendeventhesetvalueofthezoneis150Pa.Thetotalpressurelevelofthemainductis300Paandhighvelocityrequiressoundattenuatorinallbranches.

Usinglowvelocitiesandconstantductsizeinzoneducts,thestaticpressuremaintainconstant.Thereisnoneedofzonalsoundattenuators.Thetotalpressurelevelofthesystemislow(110Pa)andthustheperformanceisenergyefficient.ConstantstaticpressuremakespossibletointroducelinearcontrolofzonedampersandintegrateCAVandVAVterminalsinthesamezoneduct.Linearizationgivesalsoadvantageforcommissioningandairflowratemonitoring.Byknowingthestaticpressureandthepositionofthedamper,itmakeseasilytochecktheactualairflowrateofthespace.

32 33

Zonal level

Fig. 40. The difference of pressure levels between the equal friction loss (panel above) and constant static pressure methods (panel below) (by courtesy of Skanska).

34

Inthezonallevel,thesupplyandexhaustairflowrates

shouldbebalanced.Inthesupplyside,theconstant

pressuredamperisequippedwiththemeasurement

unitthatgivesthesetvalueforexhaustside.Exhaust

airflowratesfollowsasaslavethesupplyside.InFig.

41,thereispresentedinHaltonVariochilledbeam

systemacentralizedexhaustconceptwhereexhaust

airflowsaretransferredthroughwallorceilinginstalled

transfergrillestowardstocentralizedexhaustpoint.

Thesupplyzonalductstaticpressureiskeptconstant

toensuretheoptimumoperationoftheHaltonRex

chilledbeamandtheHaltonJazactivediffuser.

TheMSSpressuresensorunitmeasurestheduct

staticpressureandsendsthevaluetotheHFS

pressurecontroller(0-10Vdc).TheHFScontrolsthe

ductstaticpressurelevelaccordingtothesetpointby

changingdamperbladeposition.

Zonal level

Fig. 41. Constant static pressure supply zone with centralized zone exhaust in Halton Rex chilled beam.

Fig. 44. In large ductworks, the airflow rates should also balancing in the main air conduit.

TheHFSmeasurestheactualairflowrateonsupply

ductandsendsit(networkvariableand/or0-10Vdc)to

theexhaustairflowcontroldamper,HFB.The

measuredsupplyairflowrateisthesetpointtothe

exhaustairflowdampertoensurebalancedventilation

ineachzone.TheexhaustHFBsetpointcanbeshifted

relatedtothesupplyairflowtomaintainthedesigned

over-pressureorunder-pressurebalanceofspace.

(Fig.42).

Theexhaustunitcanbeeitheracommonexhaust

grilleorJazdiffusersinstalledthespaces.

Largerfloorspacecanbedividedtoseveralduct

zonesandsupplyductpressureleveliscontrolled

individuallyoneachzone.Thismakesitpossibleto

havedifferentductpressurelevelsondifferentzones

andenablesuseofdifferentproductslikeHaltonRex

beamandHaltonJazdiffuseratsamefloorspace

(Fig.43).

Inthemainsupplyandexhaustducts,thereare

installedstaticpressuremeasurementunits.Those

unitsgivethesetstaticpressurethatthefanatair-

handlingunitcontrol(Fig.44).

34 35

Zonal level

The MSS pressure sensor unit measures the duct static pressure and sends the value to the HFS pressure controller (0-10 Vdc). The HFS controls the duct static pressure level according to the set point by changing damper blade position.

The HFS measures the actual airflow rate on supply duct and sends it (network variable and/or 0-10 Vdc) to the exhaust airflow control damper, HFB. The measured supply airflow rate is the setpoint to the exhaust airflow damper to ensure balanced ventilation in each zone. The exhaust HFB setpoint can be shifted related to the supply airflow to maintain the designed over-pressure or under-pressure balance of space. (Fig.42).

The exhaust unit can be either a common exhaust grille or Jaz diffusers installed the spaces.

Room units: Room units:

Supply: Vario Rex chilled beam with integrated room controller

Supply: Vario Jax active diffuser with integrated room controller

Supply: Vario Jax active diffuser with integrated room controller

Exhaust: Common exhaust grille.

Exhaust: Vario Jaz exhaust unit with equal outlook with supply unit

Fig. 42. Constant static pressure supply zone with the combination of space and centralized exhaust. Larger floor space can be divided to several duct zones and supply duct pressure level is controlled individually on each zone. This makes it possible to have different duct pressure levels on different zones and enables use of different products like Vario Rex and Vario Jaz at same floor space (Fig.43).

Fig. 43. Office floor plan with compbination of Vario Jaz and Rex units and with Vario Jaz units.

In the main supply and exhaust ducts, there are installed static pressure measurement units. Those units give the set static pressure that the fan at air-handling unit control (Fig. 44).

Fig. 44. In large ductworks, the airflow rates should also balancing in the main air conduit.

Fig. 43. Office floor plan with combination of Halton Jaz diffuser and Halton Rex units and with Halton Jaz units.

Fig. 42. Constant static pressure supply zone with the combination of space and centralized exhaust.

Room units Room unitsSupply:Halton Rex chilled beam with integrated room controller

Supply:Halton Jaz active diffuser with integrated room controller

Exhaust:Common exhaust grille.

Supply:Halton Jaz active diffuser with integrated room controller

Exhaust:Halton Jaz exhaust unit with equal outlook with supply unit

36

Zonal level

IntheTable13,thereisshownestimatedfloorareas

ofthezonethatarepossibletocoverwith10%and

30%ratioofthemeetingrooms(4l/sperm2)and

officerooms(1-2l/sperm2).Thisdepictsthatwith

thefollowingassumptionthezoneareaisfrom300..

900m2.Itshouldbenotedthatactualzonesshouldbe

specifiedwiththeductworkcalculationswherethe

staticpressurelevelsovertheductworkareanalyzed

indifferentoperationconditions.

Withtheusedductworktopologyandductsize,the

changesinthestaticpressureoverthezoneshouldbe

analyzed.Largervariationinthestaticpressureleads

higherinaccuracywiththeairflowrateoftheterminal

units.

Chilledbeamsoperatetypicallyatlevelof80..100Pa.

Inordertoachieveairflowrateinaccuracyoflessthan

10%atroomterminallevel,thedeviationofthestatic

pressurelevelcan’tbehigherthan10...20Pa.

Designofthestaticpressureductworkhappensinthe

followingsteps:

• Airflow rate

Calculatemaximumzoneairflowrateincludingthe

needofmeetingroomsandboostedoffices.

• Size of zone ducts

Airvelocitymax3..5m/sinsupplyduct

Airvelocityof5m/sinexhaustduct

Wholezonesupplyductasequalsize

Exhaustductsizedbyconstantairvelocity

• Connection ducts of terminal units

Thelengthofconnectionductisrecommendedto

beshort<3m.

• Number of units

Typically10-20unitsinductbranch(withringduct

numberofunitsmuchhigher)

• Static pressure sensor

Locatethepressuresensorat1/2--2/3ofthebranch

lengthinsupplyduct

Exhaustductsensorat1/2–1/1ofthebranch

length

• Static pressure set point

DesignroomunitswithHaltonHITandincrease

5-10Patothesetpoint.

• Selection of the zone control damper

5-7m/swithmaximumairflowrate

1-2m/swithminimumairflowrate

Ventilation rate Duct size 400 Duct size 500

Offices Meeting rooms

Percentage of meeting rooms

Percentage of meeting rooms

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

1 4 590 400 905 620

1.5 4 430 335 675 525

2 4 340 290 535 455

Table 13. Zone estimation according to ventilation rates.

3.1.1. Design of constant pressure ductwork

The maximum variation of the static pressure

could be 10-20 Pa to achieve inaccuracy of airflow

rate less than 10 % at terminal units. By using low

air velocity of 3.. 5 m/s and the constant duct size,

it is possible to maintain constant static pressure in

zone duct. Depending on the design airflow rates

and duct topology, 10-20 terminal units could be

installed in a zone.

Constantpressureductdesignisbasedonthestatic

regainafterductsection.Thesamesizeofzoneduct

andrelativelylowvelocityguaranteesthatthe

pressureconversationfromdynamicpressuretostatic

pressurehappensafterthejunctionandthestatic

pressureisalmostconstantoverthewholezoneduct.

Itshouldbenotedinexhaustductisnotpossibleto

utllizestaticregainprinciple.Ductsaresizedbasedon

constantvelocity.Theairvelocitycouldbehigherin

exhaustductthaninsupplyairduct.Theairvelocityof

5m/scouldbeusedinexhaustducts.

Designstartswithdeterminationofthezones.Thezone

couldbethewholefloorareaorpartofthefloor.The

totalrequiredairflowrateisdeterminedforthespecified

zone.Theairflowrateiscomputedtakenintoaccountof

thefutureneedstochangespaceprogram.Inthis

phase,itisimportanttoconsiderwhatisthereserved

ratioofthemeeting(4l/sperm2)andofficeroom(2l/s

per m2).Also,thepossiblelocation(beginningorendof

duct)ofmeetingsroomshouldbeconsidered.

Byusinginthestartingpointairvelocityof3..5m/s,

theductsizeisdetermined.Inpractice,thespace

constraingivesthelimitforpossibleductsize.Forthe

roundducts,themaximumsizeistypically400or

500mm.Withwiderectangularducts,itispossibleto

increasetothesupplyairflowratewiththesame

heightofthespaceconstrain.

36 37

Examples of ductwork topology

The final ductwork topology and duct size

determination is a project specific issue. Many

cases trade-offs are required e.g. because of the

space constrains and possible locations of air

conduit. It is recommended to use symmetric

ductwork. In large ductworks, ring ducts assist to

maintain the constant static pressure.

InFig.45,thereisanexampleofthevariationofthe

staticpressureinaductworkwherethemaximumair

velocityandthetotalairflowrateare5m/sand258l/s

.Theconstantsizeofroundductis315mmandthe

lengthoftheductis50m.Thestaticpressuresensor

isinstalledinthemiddleofthezone.Thepressure

dropoftheroomunitsissetto80Pa.Intheduct

zone,thereare9officeswiththeairflowrateof20l/s.

Attheendoftheductwork,thereismeetingarea

withtwo40l/sroomunits.Inthiscase,thestatic

pressurevariedonly10Painthemainductfromthe

setvalueleadinginaccuracyof5%intheroomunit.

Thefinalductworktopologyandductsize

determinationisaprojectspecificissue.Manycases

trade-offsarerequired.HaltonHITBalanceassiststhe

designoftheductworks.Itmakespossibletoanalyze

differentductworktopologies,thelocationofthe

staticpressuresensorandductsizes.HitBalance

makespossibletooptimizesolutionforthesetdesign

Zonal level

demandsandtoguaranteetheperformance.InFig.

46,thereisanexampleoffloorductworkdesign

wherethestaticpressurelevelsareanalyzedina

complicateductwork.

Itisrecommendedtousesymmetricductwork.Also

inlargeductworks,itisrecommendedtointroduce

ringductstomaintaintheconstantstaticpressure.In

Fig.47,thereisanexampleofthefloorlevelwhere

theringductconceptisintroduced.

Fig. 45. The static pressure and air flow rates in a case-study constant pressure duct.

Fig. 47. An example of ring duct design (by courtesy of Skanska).

needsanewfiguresothatcansee

thefigures'

38

Zonal level

Fig. 46. An example of complicate ductwork where the performance is optimized with Hit Balance.

38 39

3.1.2 System & component overview

Theconstantstaticpressurelevelismaintainedinthe

ductworkwithHFS-controldamper(Fig.48)andthe

staticmeasurementunitMSS(Fig.49).ForHFS-

controldamper,thereisintegratedwithflow

measurementunit(0-10Voutputsignal)asan

accessory.Theoperationrangeofthemeasurement

deviceisfrom1-7m/s.Soundattenuatorwith

differentlengths(600and100mm)isalsoavailableas

anaccessory.TheMSSunitincludesstatictype

pressuremeasurementsensorwithdigitaldisplay.

Adjustablepressuremeasurementranges

correspondingto0-10VDCoutputsignal.The

measurementinaccuracyofMSSlessthan±10%in

typicalapplications.

Intheexhaustsideasaslaveforsupply,HFBcontrol

damperisused(Fig.50).Thevariableairflowdamper

HFBcontainsanaveragingairflowmeasurement

probe,airflowcontrollerandactuator.Airflowis

controlledbasedonactualflowmeasurementby

changingthedamperbladeposition.Theoperation

rangeofthemeasurementdeviceisfrom1-7m/s.

Soundattenuatorwithdifferentlengths(600and100

mm)isalsoavailableasanaccessory.

Intherectangularducts,controldamperUKVisused

tomaintainconstantstaticpressureorthesetairflow

rate(Fig.51).UKVissuitableforlargeairflowrates

fromfacevelocityof1m/sup-to11m/sinsome

applications.UKVwidthisfrom200mmto1600and

heightfrom200mmto1000withtheincrementsof

50mm.

Zonal level

Fig. 48. Zone damper HFS.

Fig. 49. Measurement unit MSS.

Fig. 50. Zone damper HFB.

Fig. 51. Zone damper UKV for rectangular ducts.

40

Zonal level

3.1.3 Example of the specification of zone airflow

rates

Application of Halton Rex Chilled Beam with

Centralized Exhaust

InHaltonRexchilledbeamsolution,airflowrateis

variedinresponsetospaceandzoneoccupancy.In

unoccupiedspaces,outdoorairflowratesaresetto

minimumlevele.g.at0.3l/sperm2.Whentheroom

isoccupied,airflowratesareincreased(e.g.1.2-2l/s

per m2)tomeetairqualitytargets.Inmeetingrooms

whenoccupancyrateincreasedorthereisaneedto

boostairflowrate,theairflowratesaremodulating

e.g.upto4l/sperm2.Thusinthezoneductlevel,the

airflowratevariedalot.

InFig.52,thereisshownaHaltonRexchilledbeam

conceptforzonelevelairflowbalancing.Insupply

duct,constantstaticpressureismaintainedinsupply

ductandthemeasuredsupplyairflowrategivesthe

setvalueforexhaustdamper.

Selection of control dampers is based on the duct

size and the minimum and maximum airflow rate of

zone damper. When the maximum airflow rate is

determined, there is need to specify what is the

ration between meeting and office rooms. Typically

15- 50 % of space area is reserved for meeting

rooms.

Asanexampleofthezonedesign,thereistheareaof

240m2whereare24piecesof10m2roommodules.

Asabreakdownoftheroomunits,thereare18

offices(15l/spermodule)and6piecesofmeeting

rooms(40l/spermodule).Thus,thetotalairflowrate

is510l/s.Withtheselectionof400mmroundduct,

thisleadstothemaximumvelocityof~4m/s.The

minimumairflowrateis0.5l/sperm2means120l/s

and1m/svelocityintheductwork.

Fig. 52. Airflow rate control at zonal level with a Halton Rex chilled beam concept.

40 41

Zonal level

Halton Vario Optimizer (HVO)

Byoptimizingfanpower,itispossibletoreacha

significantenergysavings.Proportionalitylawsseta

correlationwherethepowerconsumptionofthefan

changestothirdpowerwithvolumetricflowratio.

HaltonVariosystem'sOptimizermaintainsduct

pressureaslowaspossibleandcommunicateswith

zonalpressurecontroldampers.

System solution

Byoptimizingfanpower,itispossibletoreacha

significantenergysavings.Proportionalitylawsseta

correlationwherethepowerconsumptionofthefan

changestothirdpowerwithvolumetricflowratio.In

demand-basedsystem,roomairflowrateiscontrolledin

roomunits.Constantpressureductworkismaintained

withzonecontroldampers.Ifthestaticduckpressureis

notoptimized,thepressureisunnecessaryhigh.

HaltonVariosystem'sOptimizerconsiststhree

hierarchiclevelsoperations:masterlevel,zonallevel

HVO-slaveunitsandzonaldamperswhosefunctions

are described below:

Fig. 53. The system architecture of Halton Vario fan optimizator (HVO).

HaltonVarioOptimizer(HVO)mastermodule:

•CommunicationtoAHU

•Network–analog(0-10V)(4-20mA)

•Monitorsallslavemodules

•AHUminimumandmaximumairflow

TheHVOslave

•CommunicationtoHVOmaster

•Network

•Upto6constantpressuredamper

•Damperposition

•Individualairflowmeasurement

•4inputsforfiredampers

Zonedamper

•CommunicationwithHVOslave

•Network

•Damperposition

•Airflow

InFig.53,thereispresentedthesystemarchitecture

ofHVO-concept.

The HVO slave

• Communication to HVO master • Network • Up to 6 constant pressure damper • Damper position • Individual airflow measurement • 4 inputs for fire damper

Zone damper

• Communication with HVO slave • Network • Damper position • Airflow

In Fig. 53, there is presented the system architecture of HVO- concept.

Fig. 53. The system architecture of Halton Vario fan optimizator (HVO).

42

Zonal level

Operation

Thetargetistomaintainaductpressurelevelthatis

aslowaspossibleinordertosaveonfanpower

consumption.TheHaltonVariosystem'sOptimizer

HVOmonitorstheopeningofeachzonedamperand

detectsthemostopendamper.Ifthismost

demandingandopendamperhasunnecessaryhigh

pressuredroplosslevel,theHVOadjuststheAir

HandlingUnit´spressureattheoptimallevel.Thisis

conductedwiththeTrimandResponseLogicleading

toalowerpressurelevelintheentirewholesystem.

TheHVO-slavemonitorsallthedamperspositionof

Fig. 54. Optimization of the static pressure level with Halton Vario Optimizator.

Communication

Halton Vario offers a total solution from management to room conditions, zone static pressure and the pressure optimization of air-handling unit. Halton Vario supports the most common communication protocols: LON, BACnet and MODbus. Halton Vario Rex and Jaz control systems covers the operation at room, zone and central level (Fig. 55). Halton Vario Master- unit is integrated to building management system (BMS) where operation of the system is monitored and the collected information is utilized in facility management.

eachdamperinthezone.Ineachzone,apressure

sensorisinstalled(MSS)tothezonedamperthat

registersthepressureineachzone.Inthezone

damper,theairflowrateisalsomeasuredwiththe

measurementdevice.

Informationoftheopeningofthedamperandairflow

rateissenttotheHVOslave.HVOslave-units

maintaintheadjustedstaticpressureandairflowrate

inthezoneandthusguaranteeexcellentthermal

comfortineachworkplace.

Ifthedamperpositionisaccordingtotheactualneed

forflowandstaticpressure,thereisnoneedfor

Fig. 54. Optimization of the static pressure level with Halton Vario system's Optimizator.

thisisaBelimoimage*.Canwe

useit?shouldweputbelow

Belimosname?

42 43

Zonal level

Fig. 55. Halton Vario control platform and integration with BMS.

adjustment.Butifthedamperopeningisabovethe

specifiedposition,theHVO-slavewillsendamessage

theHVOmasterthatmoreairflowisrequired.The

HVO-mastersendsalsoamessagetotheAHUto

increasethestaticpressuretogetmoreairflowtothe

spaces.

Ifthedamperopeningisbelowacertainpointe.g.

60%,theHVO-mastersendsasignaltotheAHUto

decreasethepressure.Thisensuresthatthemost

opendamperpositionwillbeincreased.

Thevaluesaresentevery2minutes(adjustable)to

adjustthestaticpressure.TheHVOmastermaintains

thesetminimumstaticattheair-handling.Also,the

HVOcomputersthesumofthezoneairflowratesand

guaranteesthatthezonalairflowrateisovertheset

minimumairflowrate.

HVOfanoptimizationhappenwithfollowingthree

steps(Fig.54):

1.Zonecontroldampersmaintainthesetstatic

pressure

2.Airflowratereducesandzonedampersareclosing

tomaintainthesetstaticpressure

3.HVOreducesthetotalstaticpressurelevelatair-

handlingunitandzonedampersopenstooptimal

positionthatmaintainthesetstaticpressureinzone

levels.

Communication

HaltonVariosystemoffersatotalsolutionfrom

managementtoroomconditions,zonestaticpressure

andthepressureoptimizationofair-handlingunit.

HaltonVariosystemsupportsthemostcommon

communicationprotocols:LON,BACnetandModbus.

HaltonRexbeamandJazdiffusercontrolsystems

coverstheoperationatroom,zoneandcentrallevel

(Fig.55).HaltonVariosystem'sMaster-unitis

integratedtobuildingmanagementsystem(BMS)

whereoperationofthesystemismonitoredandthe

collectedinformationisutilizedinfacilitymanagement.

Fig. 55. Halton Vario system control platform and integration with BMS.

Enabling Wellbeing

Halton OyEsterinportti 200240 HELSINKI, FinlandTel. +358 (0)9 221 2121www.halton.com