chilled beams comfort energy savings control · 2015-02-27 · comfort energy savings control....

Chilled BeamsComfort

Energy SavingsControl

Swegon is a Registered Provider with The American Institute of Architects Continuing Education Systems. Credit earned on completion of this program will be reported to CES Records for AIA members. Certificates of Completion for non-AIA members are available on request.

This program is registered with the AIA/CES for continuing professional education. As such, it does not include content that may be deemed or construed to be an approval or endorsement by the AIA of any material of construction or any method or manner of handling, using, distributing, or dealing in any material or product. Questions related to specific materials, methods, and services will be addressed at the conclusion of this presentation.

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© 2012 by Swegon Air Academy and Swegon, Inc. a wholly owned subsidiary of Swegon AB

Learning Objectives

At the end of this program, participants will be able to:

1. Understand functions and benefits of chilled beam systems

2. Select energy-efficient types of air-water devices for room

conditioning

3. Understand the SD elements of chilled beam systems

4. Understand the HSW elements of chilled beam systems

5. Identify possible LEED credits available by applying chilled beams

Active chilled beam basicsSmall primary air flow - high capacity

Primary air40 cfm59 F

Induced air160 cfm

77 F

Distributed air200 cfm

62 F

Primary air40 cfm64 F

Induced air160 cfm

68 FDistributed air

200 cfm85 F

Cooling Heating

Active chilled beam basics Induction

Why chilled beams are popular

CV Chilled Beam

DCV Chilled Beam

VAV

•Why 20% less energy than other systems?

• More efficient distribution of cooling energy (water vs. air)

• Air for ventilation only -> less fan energy

• More efficient central fans -> less fan energy

• CHWS temperature higher -> Greater chiller efficiency

• More efficient central dehumidification

•Sustainable Design - Energy Savings

•Possible 30% more energy savings when DCV used

•Probable LEED credits for optimizing

energy performance.


9 Chilled Beams 9

Air10” duct

Capacity 9900 Btuh(20 ft/s ∆t 14 F)

Water3/4” pipe

Capacity 9900 Btuh(110 ft/m ∆t 7 F)

Energy & space savings


Water-based cooling more efficient than Air-based cooling

10 år-månad-dagProjekt10

Chilled beam basicsWhy is your VAV air handler so big?

Ventilation (breathing air)~20-25% of airflow

CoolingUp to 75-80% of airflow

11 Chilled Beams

•*Costs vary by project


11

System Cooling energy

Fan energy

Maintenance

Fan Coil 1.00 1.00 1.00

Chilled beam – CV 0.91 0.77 0.50

Chilled Beam - DCV 0.87 0.72 0.50

• Sustainable Design - Space Savings

•Plenum height typically halved

•Lower device height (6” to 9” typ.)•Smaller ducts•Horizontal ducting


Chilled Beam

DUCT

DIFFUSER

VAV BoxOr

Fan Coil UnitSaved vertical space

Deck

Ceiling

– Impact of chilled beam use

• Example: 20 floor hotel

– Fan coil design – 212’ (2544”)

– Chilled beam design (2444”)

– Possible extra floor

• (10) rooms with $400k/room

• $4M 1st year revenue increase

– Possible higher ceilings

– Possible reduced building height

• Sustainable Design - Space Savings

•Smaller mechanical room / space

•Smaller air handler

•Fewer system components


• Sustainable Design – Reduced complexity


Fan Coil Unit• Requires fan/motor maintenance• Requires 120v power (min), wiring• Requires filters and regular

maintenance• Requires drain pans, condensate lines,

possible condensate pumps

Chilled Beam• No fans• No operating electricity• No filters requiring maintenance• No drain pans

• Adapt to reprogrammed spaces

• Reconfigure in the fieldBefore

After


Sustainable Design – Life Cycle Extension

Chilled Beam Design Principles

Normal occupancy

Full occupancy loadDesign challenge :

Risk of draft and discomfort from poor occupancy planning, or from inadequate control capabilities

Remedy:

Allow maximum ASHRAE 55 conditions in worst case.

Require beams with field adjustable air volumes and airflow patterns

•Better occupant satisfaction

•less draft

•lower noise

•controlled humidity

•improved productivity/safety

•Increased Health, Safety, Welfare

•Possible LEED credits for controllability of thermal comfort

•ASHRAE 55 comfort conditions



Greater comfort from field adjustability

Chilled Beam Timeline

1950sRadiant panels

1984Passive Chilled Beam

1987

Active Chilled Beam

2004

Comfort Module

Recent developments

• Greater airflow flexibility

Ø4”Height 6.1”

Ø5”Height 7.3”

Ø6”Height 10.7”

Recent developments

• Greater architectural flexibility

– Variable faceplate length and width

– Fits more ceiling types (e.g. Bandraster)

– Reduced height (~6” possible)

Ø4”Height 6.1”

Ø6”Height 10.7”Ø5”

Height 7.3”

Recent developments

• Reduced cost of installation

• Fewer duct connections and fittings

Chilled beam applications

In-ceiling

Sidewall

Under window induction units

Under window induction units

Sidewall – horizontal discharge

27 år-månad-dagProjekt

Room Control

Swegon CONDUCTOR W4• Modulating water and air flow• Occupied/Unoccupied modes• Boost recovery mode• Temperature response• Occupancy response• Open window response• Condensation response• In-room & BAS setpoint

Read/WriteFactory-mounted and wired:• Room Controller• Valves/Actuators• Condensation sensorFactory furnished / field mounted:• Room sensor• Occupancy sensor• CO2 sensor• Damper with factory mounted

actuator


Demand ControlTypical Conference Room


Demand Control


• Due to dry cooling operation the beam system is used where the

internal humidity loads are moderate.

• …beam systems must be designed to ensure that there is no risk

of condensation

• Dehumidification of the primary supply air by the main air

handling plant is used to control humidity

• Studies have shown that the inlet water temperature can be

slightly lower than the dew point of the space before

condensation appears, and even lower (2.7 °F) before droplets

form


• US Department of Energy:

• …strict dehumidification of the supply air.

• Since chilled beams are most cost effectively used to do only

sensible cooling, dehumidification becomes the job of the central

air handler.

• Added benefit of controlled humidity = controlled comfort


90ºF db 43ºF wb(13,3gr)

75ºF db62.5F wb

(62 gr)

55ºF db53,5ºF wb(60 gr)

System Selection & Control

79,2ºF db65,3ºF wb(10,4gr)

81ºF db65,5ºF wb(10,4gr)

DOAS SA13750 CFM

EA 11250 CFM

NEW YORK 90ºFdb 73ºFwb

ROOM 73ºFdb 62,5ºFwb

2 pers/12m²

40m³/h x pers

1 Parasol 600x1200 LF-MMMM

45ºF 55ºF

154kW

COP=3

57ºF 62,6ºF

COP=4,5

75ºF db 59ºF wb (60 gr)

57°F

62,6°F

105 kW

12 m²

88ºF db70,2ºF wb(12,3gr)

Moisture control strategy, primary

90ºF db 73ºF wb(95gr)

TRA: 75ºF db 65gr

TPRI: 55ºF db, 60gr

79,2ºF db65,3ºF wb

(74gr)

81ºF db66,2ºF wb

(74gr)

TCHWS: 57°F

88ºF db70,8ºF wb

(87gr)

2. CHILLED BEAM Chilled Water Supply Temperature kept above dewpoint of building, as measured at the AHU return.

3. Individual zones protected from unintentional moisture removal (condensation) by moisture sensors and normally closed water valves.

1. AHU. Sized to provide ventilation air and entire latent load of building. Condensation occurs here.

4. Dewpoint measured at AHU return. BAS adjusts chilled beam water temperature to remain above the measured DP.

RH


Primary air55 F db

53,5 F wb(60 gr/lb)

Moisture control strategy, secondary

5. CONDENSATION SENSOR – detects moisture before droplets form, signals BAS to close CHWS valve

Induced air

75 F db55 F dewpoint


Medtronic, Italy

Moisture Content

0

50

100

150

200

250

300

Gothe

nbur

g, S

weden

Well

ingto

n, New

Zea

land

Mad

rid, S

pain

Dijon,

Fra

nce

Lisbo

n, Por

tuga

lIst

anbu

l,Tur

key

Bosto

n, U

SANew

Yor

k, USA*

Miam

i, USA

Ahmed

abad

, India

Abu D

habi,

UAE

Cities

Hum

idity

(gr

ains

/lb) 0.4% ASHRAE grains/lb project design


Performance Data Reliability


Cooling from Induced Air +

Cooling from Primary Air=

Total chilled beam cooling

Reliable data required!

How is capacity measured?• Tested & reported as an assembly • Is not simply a sum of component capacity• Active chilled beams – Standard EN 15116

(ASHRAE is working on Standard 200, but it is not complete.)

• Passive chilled beams – Standard EN 14518(replaced DIN 4715)

How is capacity certified?• Eurovent certification program uses EN Standards as method of test,

random sampling to enforce • AHRI certification program is not in place

(Intending to use ASHRAE 200 – awaiting its completion)

Glass quality

• Solar Heat Gain Coefficient / Sun Reduction Factor !!

Most important

• 0.3 total factor or lower recommended

• U-Value/K-Factor of less importance


Higher quality material = lower cooling costs

Req’d

Cooling

capacity

(Btuh)

Shading factor

2 pane

glazing

0.76

Brand 1

grey

0.48

Brand 1

upgrade

0.31

Build

ing m

at’l

Light 2148 1605 1308

Medium 2022 1513 1247

Heavy 1875 1383 1113

Chilled beam cooling capacity required, as function of glass quality and construction material density thermal mass.

Higher initial investment costs - very short pay-back period!


Selection: Which beam is the right beam?


Model 4-way Active

2-way Active

1-way Active

Passive

Functions-cooling-cooling & heating-ventilation

yesyesyes

yesyesyes

yesyesyes

yesnono

Features-risk of draft-airflow control-installation time

lowestgoodlowest

lowgoodlow

lowgoodlow

highpoorlow

Configuration-overall height-modular ceilings-exposed ceilings-wall mount-continuous “linear” appearance

lowyesyesnono

lowestyesyesnoyes

lownonoyesno

lowyesyesnoyes

• Typical applications:

– Offices

– Hotel rooms

– Hospital wards

– Retail spaces

•Apply with care:

•! Spaces w/ high ventilation rates

•! Spaces with concurrent heat & contaminant loads

•! Spaces with increased infiltration via open doors

etc.


Chilled Beam Applications

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please access the evaluation for this course by logging into CES Discovery and clicking on the Course Evaluation

link on the left side of the page.

chilled beams comfort energy savings control · 2015-02-27 · comfort energy savings control....

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