halton hvac handbook chilled bean design guide

8/13/2019 Halton HVAC Handbook Chilled Bean Design Guide

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Care for Indoor Air

Halton- Chilled Beam Design Guide


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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 Product selection 25

3.10 Indoor climate conditions design 26

3.11 Management of room conditions 27

3.12 Case study 30

4. Passive chilled beams

4.1 Passive chilled beam system 31

4.2 Chilled beam system design 32

4.3 Chilled beam model selection 33

4.4 Chilled beam orientation and ventilation arrangements 35

4.5 Operation range definition 37

4.6 Pre-selection and selection 38

4.7 Design of indoor climate conditions 40

4.8 Management of room conditions 48

5. Customised service beams

5.1 Luminaires and other integrated technical services 42

Contents Chilled Beam Design Guide

Contents


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Chilled beam system

Haltons 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

Haltons 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 thermalconditions with quiet and energy-efficient operation.

The system can be realized with active or passive chilled

beams, integrated multi-service chilled beams, or

bulkhead-installed horizontal induction units.

Chilled beam system design

A chilled beam system provides excellent indoor climate

conditions and cost-efficient life-cycle costs when realization

is managed properly from design to use of the building,

covering:

Definition of targets

System design

Product selection

Room control

Ductwork and pipework design

Central systems design

Eventual free cooling / heat pump applications

Installation and commissioning

Verification of indoor climate conditions

Flexibility throughout the lifetime of the building

Modern office buildings are designed to allow flexibility inuse 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:

Traditional design

AdaptableClimateconcept

Flexibility requirements can affect the design, logistics in

transport and at the site, and the tasks required when room

layout or the use of space changes.

Halton chilled beams

Haltons chilled beam range includes many different types

and models:

Adaptable active chilled beams (ACC, ACE) for suspended-

ceiling and exposed installation

Active chilled beams for suspended-ceiling installation

(ABC, ABD)

Active chilled beams for exposed installation (ABE, ABH)

Passive chilled beams for suspended-ceiling installation

(APA)

Passive chilled beams for exposed suspended-ceiling

installation (APT)

Customized active and passive service beams for both

suspended-ceiling and exposed installations Compact, bulkhead-installed induction units with uni-

directional horizontal air supply (AHH)

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.

Adaptable active chilled beams are ideal for flexible office

spaces, where office layouts are changed frequently and

spaces are shifted often between office rooms and team,

project and meeting rooms.

Passive chilled beams. Passive chilled beams are used

in the same applications as active chilled beams. There

are, however, specific conditions favoring passive beam

installations:

Applications where ventilation rates are relatively high

e.g., 0.7 0.9 cfm/ft2

Refurbishment projects where the existing ventilationsystem is to be preserved for the most part

Where ventilation is realized using a separate system

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.

Customized service beams.Active and passive

customized service chilled beams are feasible for

refurbishment projects in office and other public buildings.

The benefits of customized service beam systems are:

Effective installation of technical services and good total

quality of installations due to off-site manufacturing and

short construction process

Selection of exposed or ceiling-integrated beams on the

basis of a feasibility study for the building by consulting

engineers

The ability to create aesthetic interior

1. Chilled beam system


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Target definition

2. Target definition

When the main targets for system operation and performance are set, 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.

In addition, module sizing and flexibility requirements are important factors influencing both design decisions and

life-cycle cost management for the building. It is also important to take into account national and 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

Operative temperature Winter F 71 2 71 3.5 71 5

Operative temperature Summer F 76 2 76 3 76 4Vertical temperature gradient 0.3 ft / 0.3 ft F 3 5 7

Mean air velocity Winter fpm 30 35 40

Mean air velocity Summer fpm 35 43 50

Sound pressure level Office rooms NC 30 33 35

Sound pressure level Landscape offices NC 35 38 40

Ventilation rate Office rooms cfm/ft2 0.45 0.3 0.2

Ventilation rate Landscape offices cfm/ft2 0.35 0.25 0.15

Ventilation rate Meeting rooms cfm/ft2 1.3 0.9 0.5

Design assumptions Occupancy:

Clothing:

office rooms 100 ft2per person

landscape offices 70 ft2per person

meeting rooms 50 ft2per person

0.5 clo summer; 1.0 clo winter

Indoor climate design conditions:

Thermal conditions as specified in national or

international standards or classifications

Room air temperature or operative temperature

Mean room air velocity or draught rate (DR)

Internal surface temperatures and radiant

asymmetry

Air quality criteria as specified in national or

international standards or classifications air qualityoften is indicated in terms of:

Outdoor air flow rate

CO2concentration

Sound level requirement is expressed as:

Noise Criterion NC

Sound pressure level Lp(A)

Typical space design data

Room and module dimensions

Space usage, internal load and occupancy levels

Window and wall types, and solar shading

Life cycle costs:

Target system investment cost level ($/ft2)

Energy-efficiency targets' levels can be expressed

as specific level of consumption of heating energy

and air conditioning and electric power (fan power).

The building should be classified according to these

consumption levels.

Maintenance level targets indicate:

Predicted service intervals

Labor demand

Accessibility of service points

Need to replace parts / replacement interval

(valve, filter, motor, and other parts.)

Flexibility for change:

Flexibility requirements can be characterized with

the required tasks when layout or the use of space

changes:

Need for office / meeting room changes

Need to relocate internal walls

Need for installation / reconnection of terminal

units or control units

Adjustment of airflow rates

Adjustment of water flow rates

Other adjustments (e.g. personal requirements)

Order delivery chain:

Targets for order delivery indicate the versatility of

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 systemThe chilled beam system is an air/water system for high-

temperature cooling and low-temperature heating that

utilizes the excellent heat transfer properties of water

and provides a good indoor climate energy-efficiently.

Typically, a chilled beam system is realized as a dedicated

outdoor air system with sufficient airflow rates to ensure

good indoor air quality.

Either the system employs a four-pipe system or a

separate perimeter heating system is used. Even two-

pipe application with system changeover between

cooling and heating is used.

Operation of the systemChilled 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 only

for chilled beams or a common chiller for air handling units

with a separate, flow-water-temperature-controlled loop for

chilled beams, preferably connected via a buffer tank.

Space temperature control is realized with variable water

flow control using either on-off or proportional control

principle.

Ventilation

Ventilation using active chilled beams is an efficient mixing

ventilation application that results in uniform air quality.

Supply air is discharged into the space through linear 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

airflow can be increased by means of an integrated

diffuser without affecting the heat transfer of the chilled

beam.

Cooling

Active 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 various free-cooling sources,like outdoor air, sea water and geothermal energy etc.

Heating

Integration of heating into chilled beams is

recommended when the specific heating capacity of the

chilled beam units is reasonably low (155 260 Btuh/ft),

and the low heat transmission through the windows

prevents a downdraught under the window.

Low-temperature heating enables the use of various

waste-heat sources. Alternatively to hydronic heating,

electric heating can be integrated in chilled beam units.

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


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Chilled beam system design

3.2 Chilled beam system design

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

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

AdaptableClimateconcept 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.

Optimized 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 73 77 F

Room temperature, winter 68 72 F

Supply air temperature 61 66 F

Water inlet temperature, cooling 57 61 F

Water inlet temperature, heating 95 104 F

Target duct pressure level 0.3 0.5 in WC

Target water flow rate, cooling 0.32 1.6 gpm

Target water flow rate, heating 0.16 0.65 gpm

Noise criteria NC 30

Outdoor air flow rate / floor area, offices 0.33 0.55 cfm/ft2

Outdoor air flow rate / floor area, meeting : 0.33 0.9 cfm/ft2

Outdoor air flow rate / effective unit length 3.6 ... 9 cfm/ft

Additional air flow rate in meeting rooms 0 ... 53 cfm per unit

Cooling capacity / floor area 25 Btuh/ft2 38 Btuh/ft2*

Cooling capacity / effective unit length 250 Btuh/ft 400 Btuh/ft *

Heating capacity / floor area 4 Btuh/ft2 19 Btuh/ft2**

Heating capacity / effective unit length 150 Btuh/ft 200 Btuh/ft **

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

Note ** It is reasonable to study the thermal conditions carefully


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System design strategies

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.

3.3 System design strategies

Adaptable system design

Adaptable system selection strategy provides benefits

to the facility owner, who can modify spaces more

quickly and with less cost over the facility's lifetime.

Thermal condition management using Halton Velocity

Control (HVC) and air quality control using Halton Air

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

strategyAdaptableClimateconcept Traditional concept

Indoor climate

conditions

Room air temperature 754 3.5 F 754 3.5 FRoom air velocity ... 50 fpm ...50 fpm

... 60 fpm temporarily during peak loadsRoom air quality

CO2- concentration

Ventilation rate

900 ppm

0.31 cfm/ft2

(variable flow in meeting rooms)

1000 ppm

0.375 cfm/ft2

(constant airflow in meeting rooms, or separate

variable airflow application)Cooling capacity

levels

2025 Btuh/ft2 2040 Btuh/ft2

Heating capacity 612 Btuh/ft2 620 Btuh/ft2

Adaptable

performance

Halton Velocity Control (HVC) is designed at normal

position (2).

Adjustment in throttle (1) and full (3) position, when

required.

Adjustment of constant airflow rates and using Halton

Air Quality (HAQ) control.

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 100130 $/ft2.

Limited flexibility in layout and for changes in

operation conditions.

Churn costs of 7501000 $/ft2.Product cost Some extra cost for flexibil ity in room units, zones,

and central system costs.

Basic investment.

Additional installations for variable flow application in

meeting rooms.Focus in product

selection

Nozzle size, length, and effective length that are the

same using adaptable active chilled beams.

Various nozzle sizes, lengths, and effective lengths

according requirements using basic active chilled

beams.

Water flow control and adjustment valves which are

selected project- specifically and installed on siteChanges in space use

and layout in the design

and installation process

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

beam selection

Eventual reselection of chilled beams after significant

changes of use or size of the spaces

Commissioning Adjustment of chilled beams on site; no traditional

commissioning needed.

Constant-pressure control dampers in zones allow

quick airflow rate adjustments and variable airflow in

meeting rooms.

Maximum limit flow valves allow quick adjustment of

water flow rates without balancing need.

Traditional commissioning comprising

manual balancing of airflow rates using adjustment

dampers

manual balancing of water flow rates using

adjustment valves

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 realize 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

Primary air from the nozzles (3.5 9 cfm/ft) induces

3 5 times the room air (depending on chilled

beam type and operating conditions).

A total airflow rate of 10 40 cfm/ft is discharged

from one/two slots into the space.

Make sure that airflow rates can be realized at actual

chamber pressure levels.

Minimum supply chamber pressure is 0.2 0.3 in

WC to ensure the correct supply air jet throw

pattern.

Check that the required throttle for balancing can be

achieved with the adjustment damper at an

acceptable sound level.

The supply airflow rate is high enough to remove

internal humidity loads.

The supply air jet should stay attached to the ceiling

(Coanda effect) and not fall directly into the occupied

zone.

Thermal loads in the occupied zone may influence

the air jet direction and air distribution in the

occupied zone.

Analyze supply jet interaction with convective flows

caused by a cold or warm window surface to ensure

that it doesn't create a draught risk.

When already detached from the ceiling, jets of two

parallel chilled beams should not collide at a velocity

level that results in a draught.

The increase of airflow rate according to demand

should not have a significant effect on the coil

cooling capacity.

Cooling using chilled beams

The thermal properties of the external walls and

window construction should be appropriate.

The required cooling capacities should be max.

20 25 Btuh/ft2.

Chilled beam capacities (250 360 Btuh/ft) match

supply airflow rates (3 9 cfm/ft) to provide good

air distribution and draught-free conditions in the

occupied zone.

Water flow rates and pressure drops of chilled

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 over-

dimensioning the heating capacities. In a modern

office building, 8 15 Btuh/ft2of floor area is typically

sufficient heating capacity.

The heating capacity of active beams is dependenton the primary airflow rate. This is why ventilation

shall be in operation when heating is required.

The heating capacity of active beams is typically

160 260 Btuh/ft, and the inlet water temperature

should be 95 115 F to create sufficient mixing

between the supply air and room air.

Both window draught due to radiation and

downward convective air movement during cold

seasons need to be eliminated.

An efficient control system is used. It isrecommended 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 inintermediate seasons.

This study was performed using computational fluid

dynamics (CFD) software. Air velocity is higher than

50 fpm in the green areas.

The images present the room air velocities in the

same space in three seasons: summer (1), spring (2)

and winter (3).

1

2

3

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

Temperature conversion

17.7 C = 64 F

24 C = 75 F

28 C = 82 F

17 C = 62.6 F

20.2 C = 68 F

22 C = 71.6 F13 C = 55.4 F

22 C = 71.6 F

25.4 C = 77.7 F


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Active chilled beam model selection

The appropriate active chilled beam model is selected by

taking into account the following factors:

Architectural design

Preferred appearance

Desire for exposed installation or a solution integrated

into a suspended ceiling

Adaptation to the ceiling

Positioning with respect to light fittings Integration of light fittings

Room design grid dimensions and available space

Requirements for flexibility and eventual partition

wall locations

Cooling capacity and ventilation rate requirements

Building services integrated into chilled beams:

Light fittings, controls, sensors, detectors, and cabling

Adaptable active chilled beams are selected when the

requirements for cooling capacities and ventilation rates need

to be adjusted along with the space layout changes or when

variable airflow is used for demand based ventilation.

3.5. Active chilled beam model selection

Active chilled beams in suspended ceiling installation

Customized 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

Customized service beams in exposed installation.


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Adaptable chilled beam concepts

Halton AdaptableClimatechilled beamsoffer unique flexibility from design through use. Their operation adapts easily

to changes in space usage, layout, or user requirements throughout the buildings 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 buildings life cycle.

3.6. Adaptable chilled beam concepts

Benefits of the Halton adaptable chilled beams:

Wide operation range simplifies design and

specification

Good thermal comfort and indoor air quality

Adjustable air flow rates

Air velocity management

Enhanced flexibility

Free location of offices and meeting rooms

Identical look of units for different

spaces

Air flow control that can be installed as

needed

Improved logistics

Smooth order-to-delivery process

Effective on-site handling

Features:

Primary air flow rate adjustment of 0.3 to 0.9 cfm/ft2

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)

Ability to achieve individual desired velocity

conditions in the occupied zone even when partition

walls are repositioned, by adapting the operation

using Halton Velocity Control

Integrated control and max. flow limiter valves for

cooling and heating capacity allowing reset without

influencing the water flows of other chilled beams

(optional)


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Primary airflow rate

Room Space type HVC position Nozzles qv1

HAQ qv2

Total qv1

+ qv2

Total qv1

+ qv2

left right cfm cfm cfm cfm/ft2

1, 2, 3 Office 3 1 32 11 43 0.48

4 Meeting room 2 2 32 0 ... 53 32 ... 85 0.9

Management of ventilation rates using

Halton Air Quality (HAQ) control

The air flow rate of the chilled beam is dependent on

Effective length, Leff

Chilled beam chamber pressure, DPm

Nozzle size, Dnoz

Halton Air Quality control unit adjustment position,

AQ

The chamber pressure is adjusted by changing the

position (a) of the airflow 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:

office spaces: 0.3 0.6 cfm/ft2

meeting rooms: 0.7 0.9 cfm/ft2

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.

Factors influencing an active chilled beams air flow rate.

Office rooms.

Meeting room.

By integrating the airflow control into the chilled beam

unit, flexibility in use of the space is ensured.

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.

See the section Constant-pressure ductwork for

efficiency for more information.


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Halton ACE 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

the beam at a minimum distance of 2 ft from the wall

and 4 in 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 4 to

20 cfm/ft when equipped with HAQ control.

The Halton Air Quality control unit does not increase

the length of the chilled beam.

Halton ACC with air quality control. In the Halton ACC

solution, the air quality control unit is at the opposite

end of the unit from the supply air connection. Thethrow 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 motorized

version) is 2 ft shorter than the total length. The look

of the Halton ACC unit is identical to that of the ABC

chilled beam without HAQ unit.

Halton ACE with air quality control in a meeting room.


Halton ACC with air quality control in a meeting room.


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Management of room conditions using

Halton Velocity Control (HVC)

Halton Velocity Control is used for adjusting room air

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.

Halton Velocity Control does not affect the primary

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 minimization

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

buildings life cycle.

Halton Velocity Control dampers are divided into

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

of HVC damper modules are used as follows:

ABC or ACC 1 ft , 1 ft 8 in, and 2 ft 8 in

ABE or ACE 1 ft, 2 ft, and 2 ft 8 in

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 = boost position.

Adjustment of local velocity conditions is possible also in an

open-plan office with Halton Velocity Control.

Partition wall located close to the chilled beam. Halton

Velocity Control is adjusted to position 1 on one side and

position 3 on the other.


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Halton Velocity Control is available for both exposed

and ceiling-installed chilled beams.

Halton Velocity Control in boost (3) and throttle (1) position in a

Halton ACC chilled beam.

Halton Velocity Control in boost (3) and throttle (1) position in a

Halton ACE chilled beam.

Case Study

Flexibility for layout changes can be designed in with the HVC and HAQ concepts. Chilled beam installation adapts

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

Primary airflow rate

Room Space type HVC position Nozzles qv1

HAQ qv2

Total qv1

+ qv2

Total qv1

+ qv2

left right cfm cfm cfm cfm/ft2

1 Office 3 1 32 11 43 0.48

2 Office 3 3 32 32 64 0.48

3/Unit A Office 1 3 32 0 32 0.48

3/Unit B Office 3 1 32 0 32 0.48


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Constant-Pressure Air Distribution System

Constant-pressure ductwork for efficiency

In 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 airflow

management using active constant-pressure control

dampers. Among these are that

chilled beams with pressure-dependent variable flow

and constant flow are combined in the same

ductwork sections and proper operation conditions

are ensured

frequent individual air flow adjustments of chilled

beam units can be made without the need to balance

the ductwork

pressure control dampers allow zone ventilation

operation hours locally, contributing to energy

conservation in office buildings where tenants office

hours tend to differ, for example


Combined pressure-dependent variable flow and constant flow.

Ductwork is divided into constant-pressure zones,

allowing individual adjustment of the air flow rates of

each room and continuous air flow control according to

demand in meeting rooms.

The ductwork is sized using low velocities (< 1200

fpm), taking into account the predicted max. flow rate

in order to minimize 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., for office room space changes). Even constant

airflow 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 airflow

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 realized 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

optimized pressure level in the ductwork using a

pressure sensor as feedback. The sensor measures the

static pressure relative to prevailing pressure in the

building.


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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 realized in different

ways:

Ducted exhaust using a variable flow control damper

Continuous balanced ducted exhaust for constant

flow

Transfer air via a grille to the corridor

Common zone exhaust tracking the variable

common supply airflow

Transfer air via a grille to the corridor

Common zone exhaust tracking the common

variable supply flow


Combination of ducted constant airflow exhaust and variable transfer

to common exhaust.

Ducted variable airflow exhaust using variable airflow 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.


22/4422

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

analyzed. 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 Indoor climate conditions

Capacity per chilled beam unit

Residual velocities for occupied zone

Supply air jet interaction with convective flows

Suitability for room module dimensions

Suitability in view of lighting fixture locations Flexibility for layout changes

Minimum recommended distance between parallel

beams

Minimum recommended distance between chilled

beam and wall/ceiling

Sidewall installation of chilled beams.

Bulkhead installation of horizontal induction units.

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

room.


23/4423

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 workspaces 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.

Exhaust air units have minor importance to the solutions operation.

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

Perpendicular to exterior wall in offices (preferable),

above the work area

Parallel to exterior wall above work area

Perimeter installation, with uni-directional supply

Corridor installation limited application, depending

on work area location and providing bi-directional

supply horizontally and downward

Uni-directional air supply

Hotel guest rooms preferably above bed (above

window as another option)

Patient ward rooms preferably above bed either

along side walls or parallel to exterior walls


24/4424

Operation range specification

3.8. Operation range specification

A chilled beam systems 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 73 77 F

Room temperature for heating 68 72 F

Supply air temperature for cooling 61 66 F

Supply air temperature for heating 61 66 F

Water inlet temperature for cooling 57 61 F

Water inlet temperature for heating 95 113 F

Target duct pressure level for cooling 0.3 0.5 inWC

Target water flow rate for cooling 0.32 1.6 gpm

Target water flow rate for heating 0.16 0.65 gpm

Outdoor air flow rate per unit floor area Offices: 0.33 0.55 cfm/ft2, meeting rooms: 0.33 0.9 (1.1) cfm/ft2

Outdoor air flow rate over effective length 3.6 ... 9 cfm/ft

Cooling capacity per unit floor area 25 (38) Btuh/ft2

Cooling capacity / beams effective length 250 (400) Btuh/ft

Heating capacity per unit floor area 4 (19) Btuh/ft2

Heating capacity / beams effective length 150 (250) Btuh/ft

Comfort / PMV -0.5 ... +0.5

Draught rate (DR) < 15%

Average room air velocity Cooling: 45 fpm

Heating: 35 fpm

Definition of design conditions and operation

parameters

Ventilation rates in spaces as rate per floor area

(cfm/ft2)

Ventilation rate in spaces as rate per person (cfm/

person)

Cooling capacity demand in spaces, in Btuh/ft2, and

actual breakdown of loads Heating capacity demand in spaces, in Btuh/ft2, and

actual breakdown of loads

Model rooms and operational parameters

Room temperature

Supply air temperature

Water inlet temperature

Target duct pressure level

Target water flow rate

Maximum sound pressure levelVerification of target design values with full-scale mock-up and CFDsimulation


25/4425

Product selection

1. Design data in cooling

Insert the supply air flow rate and temperature

Specify the temperature difference between the

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

insert the inlet water temperature and target water

flow rate.

Calculate the coil capacity using HIT Design, and

compare the coil capacity against the requirement.

Note the capacities transferred by the coil and

primary air.

2. Chilled beam location and velocity control

adjustment

The location and number of chilled beams are

specified (also, asymmetric positioning is possible).

The HVC positions are set to allow adjusting the

throw pattern in the space and providing the

required velocity conditions in the occupied zone.

To provide adaptability to load variations, use

velocity control (HVC) position 2 (normal position).

3. Air quality control adjustment

Set the HAQ airflow rate to match the required

room airflow rate.

HAQ control can be used to adjust the airflow rate

at a specified duct pressure level.

4. Space results / unit performance Check the operation parameters against system

operation conditions to verify that the operation

parameters correspond to those of the system.

5. Design data in heating

Analysis is as in the cooling case.

6. Space results / unit performance in heating

Analysis is as in the cooling case.

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

3.9. Product selection

Make your design process more efficient with the Halton HIT Design software design tool. 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.

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

in the chosen model rooms defined by yourself using desired operation parameters.


26/4426

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)

Room air velocities in occupied zone within set limits

(non-isothermal and isothermal cases)

Temperature difference between air jet and room air

Distance at which the jet detaches from the

ceiling (Ld)

Pressure loss lower than the available pressure in

the duct (check that the noise level is within the

limits set) Adjustability of the air flow rate

In cases involving several units; check the impact of

jet interaction on occupied zone boundary velocities

(refer to Lmin

in the leaflet's quick selection table).

3.10. Indoor climate conditions design

Simultaneously with the performance values, verify also that predicted the room conditions are acceptable,

providing efficient air distribution but eliminating draught risks.

Check supply air throw pattern in heating

Simultaneously with the performance values, verify

also that the predicted room conditions are

acceptable, providing efficient air distribution:

Supply air throw pattern and room air velocities (HVC

position as in cooling)

Supply jet adequately reaching occupied zone level

Flow water temperature within recommended range Heating capacity

Impact of the HVC arrangement

Impact of the HAQ arrangement

Study optional room modules

Unit pressure drop (keep at the same level as

before)

Operation with optional room cooling load levels /

room usage

Impact of HVC in other positions (1 and 3) Impact of the HAQ arrangement

Operation in optional room module configurations

If targets for indoor climate condition are not met,

change the length and/or

beam properties, or even

the beam type

Halton HIT Design Performance view (2D).


4.0 m

v3

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

Room: Room C

Room size: 4.2 x 4.0 x 3.0 m

Room air: 24.0 C / 50 %

Heat gain: 0 W

Instal lation height: 2 .9 0 m

Inlet water temperature: 15.0 C

Outlet water temperature: 20.1 C

Wat er mas sf low: 0 .0 40 kg /s (2 x 0 .0 20 kg /s )

Coil capacity: 858 W (2 x 429 W)

Wat er p re ssur e d ro p: 0 .6 kPa

To ta l sup ply a ir fl ow : 3 6 l/ s ( 2 x 1 8 l/ s)

Supply air temperature: 18.0 C

Prima ry ai r cap ac it y: 2 58 W ( 2 x 12 9 W)

Tot al pr es sure dro p: 8 3 P a

Total sound pressure level: 19 LpAre 10m2sab

To ta l coo ling po we r: 1 11 6 W ( 2 x 5 58 W)

Dew point temperature: 12.9 C

HVC position side=1, middle=3

Temperature d if ference: 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.


27/4427

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

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.

Airflow 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 0.16 0.6 inWC.

Water flow rates can be adjusted via zone balancing

valves and the balancing valve of each chilled beam.

Halton Adaptable

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.

Even constant airflow rates of office rooms can be

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.


28/4428


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.


29/4429


Room control sequences

Room thermal conditions typically are controlled by

adjusting hot and chilled water flow rates in each

chilled beam by means of two-way valves.

Control can be based on on/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 airflow 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 optimize the supplied air

temperature to avoid an excessive vertical room

temperature gradient.

Condensation prevention can be arranged in two

stages:

System flow water temperature control based on

room air dew point calculation for critical locations. Locally in the room, using condensate detection to

close the chilled water valve.

Control sequence for heating and cooling.

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

Room control applications

Room control can be realized on the basis of

functional requirements and the desired flexibility level

using:

A self-powered standalone controller

An electric standalone controller

A traditional communicative controller

A temperature sensor, typically located in the

wall-mounted user panel

The control valve and actuator types are selected to

match the required water flow rates and control

sequences. The power supply (24 / 230 VAC) for

controller, actuators, and sensors is supplied on the

basis of the units selected.


30/4430

Case study

WP1

WP2

HVC 3 HVC 1

10 %

20 %

WP2

WP1

3.12 Case study: occupant comfort using chilled beams

The International Centre for Indoor Environment and Energy of the Technical University of Denmark (DTU) has carried out

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

chilled beam equipped with Halton Velocity Control (HVC).

Case 1

Chilled beams are installed perpendicularly to the external

wall. Velocity conditions are presented with a cooling

capacity of 16 Btuh/ft2in two different cases: Halton Velocity

Control in positions 3 and 1. Room air velocities were lower

when induction through beams was lower, even though the

cooling capacity was the same. The primary airflow 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

(by about 60%) reduced during the maximum cooling

capacity period with HVC in the throttle position (1). While

the person near the window surface (WP2) felt slightly

warmer (PMV increased from 0.4 to 0.7) when HVC was

used, the acceptability increased slightly.

Case 1. Air velocities (fpm) in the occupied zone with Halton Velocity

Control in full position.

Thermal conditions (temperature and velocity) in theoccupied 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:

High quality of general thermal comfort can be

achieved.

Halton Velocity Control decreases velocities and the

potential risk of draught discomfort.

Increased heat load and supply flow rate togetherincrease the risk of local discomfort.

Airflow interaction is an important factor affecting

thermal comfort.

The layout of chilled beams and workplaces should

be carefully considered.

Thermal flows from warm or cold windows are

important 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 sensing a draught (22 Btuh/ft2).


31/4431

Passive chilled beam system

4.1. Passive chilled beam system

Chilled beam system description

Haltons 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

Ventilation in passive chilled beam systems typically is

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.

A separate heating system e.g., perimeter heating

typically is used in passive chilled beam

installations.

Window draughts due to radiation and downward

convective air movement during cold seasons need

to be eliminated.

Schematic diagram of a chilled beam system office floor installation.


32/4432

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 73 77 F

Room temperature, winter 68 72 F

Water inlet temperature, cooling 57 61 F

Target water flow rate 0.4 1.6 gpm

Sound level NC 30

Cooling capacity / floor area 25 Btuh/ft2 38 Btuh/ft2 *

Cooling capacity / effective unit length 250 Btuh/ft 400 Btuh/ft *

Separately for ventilation

Supply air temperature 61 66 F

Outdoor air flow rate/ floor area,

offices 0.33 0.55 cfm/ft2

meeting rooms 0.33 0.9 cfm/ft2

Note * It is reasonable to study the room air velocity

conditions carefully

Note ** It is reasonable to study the thermalconditions carefully

Ventilation and air diffusion arrangement

The supply airflow rate shall be high enough to

remove internal humidity loads.

Cooling using chilled beams

Required cooling capacities should be no more than

19 25 Btuh/ft2. With well-dimensioned integrated

applications, capacities as great as 38 Btuh/ft2can

be realised.

Thermal properties of the external walls and window

construction should be reasonable.

Airtight windows with effective solar shading are

used.

The cooling capacity of passive chilled beams is

typically 150 250 Btuh/ft to avoid draughts in the

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.

The flow water temperature (typically above 57F)

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.

Water flow rates and pressure drops in chilled

beams should be in line with chilled water pipework

design and pumping cost target levels.

Passive chilled beams installed in a suspended

ceiling always require sufficiently large openings in

the ceiling for the induced room air path.

Location of chilled beams shall respect the minimum

distances from walls and ceiling presented in the

section Passive chilled beam orientation and

ventilation arrangements.

Passive chilled beam system design


33/4433

The appropriate model of passive chilled beam unit is selected

by taking into account the following factors:

Architectural design

Preferred appearance

Exposed installation or flush mounting in suspended ceiling

Hidden installation above perforated/grid ceiling

Adaptation to ceiling

Positioning in consideration of light fittings Integration of light fittings

Unit dimensions

Room design grid dimensions

Requirements for flexibility and eventual partition wall locations

Supply air diffuser integration

Exhaust valve integration

Cooling capacity requirements

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:

Light fittings, controls, sensors, detectors, and cabling

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


34/44


35/4435

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 Indoor climate conditions

Capacity per chilled beam unit

Residual velocities for the occupied zone

Convective plume interaction with supply air jet

Suitability for room module dimensions

Suitability for the lighting fixture locations

Flexibility for layout changes

Minimum distance between parallel beams

Minimum distance between chilled beam and wall/

ceiling

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


36/4436

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. 0.25 x W when S > W

H2 = min. 0.5 x W when S < W

Minimum distance between chilled beam units of L, to

ensure effective operation:

L = min. 3 x W

When a passive chilled beam is installed above a

perforated or grid ceiling, the following minimum

distances should be respected:

H3 = min. 1 in

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 1/8 in.

Side panel extensions can be used to improve

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, in

4 1.19

6 1.28

12 1.40

16 1.45

Side panel extension effect on cooling capacity.


37/4437

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 73 77 F

Water inlet temperature for cooling 57 61 F

Target water flow rate for cooling 0.32 1.6 gpm

Cooling capacity per unit floor area 25 (38) Btuh/ft2

Cooling capacity / effective beam length 250 (400) Btuh/ft

Comfort / PMV -0.5 ... +0.5

Draught rate (DR) < 15%

Local mean room air velocity Cooling: 45 fpm

Heating: 35 fpm

Definition of design conditions and operation

parameters

Cooling capacity demand in spaces, in Btuh/ft2, and


Heating capacity demand in spaces, in Btuh/ft2, and


Ventilation arrangement

Diffuser type, size, and number Ventilation rates in spaces as rate per floor area, in

cfm/ft2

Ventilation rate in spaces as rate per person, in cfm/

person

Model rooms and operational parameters

Room temperature

Supply air temperature

Water inlet temperature

Target duct pressure level

Target water flow rate Maximum sound pressure level

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

simulation.


38/4438

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:


Cooling capacity

Minimum distance between parallel units

4.6. Pre-selection and selection

Make your design process more efficient. Haltons 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.

APA cooling capacity, in Btuh/ft of

effective length

Water flow rate:

1.27 gpm

Difference between room air and water mean temperatures,

degF

Coil height (in) Coil width (in) 11 13 14 15 16 17 18 20

3 12.4 91 116 132 147 163 176 190 232

3 18.3 143 182 211 234 253 279 301 335

3 24.2 190 241 283 303 322 362 401 465

4 12.4 108 135 155 170 186 203 217 253

4 18.3 177 220 258 284 310 335 358 4184 24.2 225 280 330 364 395 426 457 532

Pre-selection example

Room dimensions 8 x 13 x 9

Room area 104 ft2

Room temperature 75 F

Ventilation rate 42 cfm

Supply air temperature 64F

Required total cooling capacity 22 Btuh/ft2

Cooling capacity 2700 Btuh

Cooling by ventilation 491 Btuh

Coil cooling capacity 1931 Btuh Presumed temperature difference DT = 14 degF

Select APA-4-153--1 159 Btuh/ft

Chilled beam APA cooling capacity, in watts per metre of effective length for water flow rate 1.27 gpm

CPA passive chilled beam quick-selection

Cooling capacity over unit length (W/m) presented for

water flow rate qmw

= 1.27 gpm.

Estimate the temperature rise in the chilled beam

(typically 2 5 degF), and calculate the temperature

difference between room air and water mean

temperature.

Temperature difference Tr- (T

w1+ T

w2)/2, degF

Where

Tr Room temperature, F

Tw1

Water flow temperature, F

Tw2

Water return temperature, F

Check the temperature difference with the HIT Design

software.

Water flow rate

qmw, gpm 0.024 0.32 0.40 0.48 0.55 0.63 0.71 0.79 0.87 0.95 1.27

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 1.27 gpm flow rate.


39/4439

Pre-selection and selection

1. Design data in cooling

Specify the temperature difference between the

inlet and outlet water of the beam or, optionally,

insert the inlet water temperature and target water

flow rate.

Calculate the coil capacity using HIT Design, and

compare the coil capacity against the requirement.

You can also insert the supply air flow rate and

temperature for total cooling capacity calculation.

2. Chilled beam location and velocity control

adjustment

The location and number of chilled beams are

specified (also, asymmetric positioning is possible).

You can also add a person for evaluating the air

velocity locally

directly below the chilled beam

in the vicinity of the beam at floor level

further from the chilled beam at floor level

3. Space results / unit performance

Check operation parameters against system

operation conditions to verify that the operation

parameters respond 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


40/4440


If indoor climate conditions targets are not met,

then change

the beam length or number of beams and/or

beam properties or even

beam type and

diffuser type and/or location

Study optional room modules

Water flow rate (keep at the same level as before)

Operation at optional room cooling load levels / room

usage

4.7. Design of indoor climate conditions

Simultaneously with the performance values, verify also that the predicted room conditions are acceptable,

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.

Operation in optional room module configurations

Study the velocities of the convective plume

entering the occupied zones and room air

velocities

Plume velocities entering the occupied zones (in the

design case)

Room air velocities in the occupied zone

Temperature difference between the plume and

ambient room air

Check the interaction of the falling convective

plume of a chilled beam and supply air throw

pattern

Simultaneously with the performance values, verify

that the predicted room conditions are acceptable,

providing efficient air distribution.

Supply jet adequately reaching the occupied zone

level Supply air that is not directed directly to chilled

beam air circulation


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

Interaction of convective plumes of a chilled beam

and a stationary person

Note that the rising convective plume of a stationary

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 x4.0 x2.8 m

O ccu pi ed z on e: h =1 .8 m / dw =0 .5 m

Room air: 24.0 C / 50 %

Heat gain: 700 W

P erf or at ed ce il in g: -

I ns ta ll at io n he ig ht : 2 .7 0 m


Outlet watertemperature: 16.7 C

Wa te r fl ow r at e: 0 .0 80 kg /s

Coil capacity: 575 W

155 W/m

W at er p r es su re d r op : 5 . 6 k P a

S up pl ya ir fl ow r at e 2 0 l /s

2.0 l/(sm2)

Supply ai r t emperature: 18.0 C

J et outl et t emperature: 21.4 C

P ri ma ry a ir c a pa ci ty : 1 4 3 W

To ta l pr es su re d ro p: -

Totalsoundpressurelevel: -

T ot al c o ol in g c ap ac it y: 7 1 8 W

72 W/m2

Dewpoint t emperature: 12.9C

Velocity control: -

Velocity point

v

T

vop

~0.15m/s

vlim= 0.20m/s

2.5 m

v3

vop

CPA-100-3900-315-1Cooling 2007.05

Room:


O ccu pi ed z on e: h =1 .8 m / dw =0 .5 m

Room air: 24.0 C / 50 %

Heat gain: 700 W

P erf or at ed ce il in g: -




Wa te r fl ow r at e: 0 .0 80 kg /s


155 W/m

W at er p r es su re d r op : 5 . 6 k P a

S up pl ya ir fl ow r at e 2 0 l /s

2.0 l/(sm2)







72 W/m2


Velocity control: -

Velocity point

v

T

v3

~0.25m/s

-2.6C

vop

~0.15m/s

vlim= 0.20m/s

2.5 m

v3

vop

CPA-100-3900-315-1Cooling 2007.05

Room:


O cc up ie d zo ne : h =1 .8 m / dw= 0.5 m

Room air: 24.0 C / 50 %

Heat gain: 700 W

P er fo ra te d ce il in g: -




Wa te r fl ow ra te : 0 .0 80 k g/ s


155 W/m

W at er p r es su re d r op : 5 .6 k Pa

S up pl y a ir f lo w ra te 2 0 l /s

2.0 l/(sm2)







72 W/m2


Velocity con trol: -

Velocity point

v

T

v3

~0.25m/s

-2.6C

vop

~0.05m/s

vlim= 0.20m/s


41/4441

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 foreach 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. Management of room conditions

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

measurement taps.

Room control

Room thermal conditions typically are controlled by

adjusting hot and chilled water flow rates in each

chilled beam by means of two-way valves.

Control can be based on on/off, pulse-width-modulated

(PWM), proportional, or proportional integral control.

Demand-based control is based on remotely setsetpoints 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.


42/4442

Customised service beams

5. Customized 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's appearance can be tailored to suit the interior.

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

An improved indoor climate is a result of excellent

temperature conditions and silent, draught-free

operation. Good conditions promote productivity and

the health of users.

Flexibility for different layouts, from open-plan to

partitioned office space, is achieved efficiently.

Assembly at the factory increases installation speed

and quality while reducing costs. Rapid connections

further reduce the commissioning time on-site.

Having a single source of responsibility lowers risk

and reduces the need for co-ordination.

Luminaires can be integrated into chilled beams or

installed as separate light fittings, regardless of chilled

beam orientation. Chilled beams are available with

direct and/or indirect luminaires.

With fewer separate pieces of equipment fixed to

the ceiling and walls, interior design better matches

the architectural vision.

The investment cost is more competitive than that of

traditional systems and suspended-ceiling

installations with separate building services.

Competitive running costs are achieved with low

maintenance demands and energy consumption.

Room height is increased, as no suspended ceiling

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/off or dimmable control and different connection

options.

Also, emergency lights can be integrated into the

chilled beams.


43/4443

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

National building codes typically require sprinkler

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.


44/44

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halton hvac handbook chilled bean design guide

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