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Chris LawrenceChris LawrenceVP Sales & Marketing
AGENDAAGENDA
•So what are So what are
Chilled Ceilings & Beams ?Chilled Ceilings & Beams ?
•Part 1 – Passive SystemsPart 1 – Passive Systems• Chilled Ceilings• Chilled Sails• Passive Beams
•Part 2 – Active systemsPart 2 – Active systems• Active Chilled Beams
•Part 3 - Reducing EnergyPart 3 - Reducing Energy• Space Humidity concerns• Design Considerations• Water System Design• Savings & LEED
•Part 4 - Solutions Part 4 - Solutions • All Air Core• 6 Way• LoFlo• Overall 1st Costs
So What are Chilled So What are Chilled Ceilings & Beams?Ceilings & Beams?
A sensible cooling only device that uses chilled water above the room dew point to remove heat
from the space.
They can be independent of, or combined with, a method of introducing conditioned outside air to
the space to meet the ASHRAE 62 ventilation requirements
ASHRAEASHRAEEngineering for the World We Live InEngineering for the World We Live In
Chilled Ceilings
Radiant & Convective sensible cooling independent of
Primary air delivery
Chilled CeilingChilled Ceiling Radiant EffectRadiant Effect
45%Radiant
55%Convective
CW Supply59-62°F
CW Return62-66°F
76°F Dry Bulb
74°F radianttemperature (black bulb)
Chilled CeilingsChilled Ceilings
Advantages Design Issues
• Low cooling output–20 to 25 BTUH/FT2
100% coverage–14 to 18 BTUH/FT2
70% coverage– Driven by surface area
• Very High cost
• Separate air system required
• Needs many connections
• Excellent thermal comfort
• Can Heat• Reduced space
requirements– Will fit into 6-8” cavity
• Self regulating– Simple controls
• Low noise• Low maintenance
ASHRAEASHRAEEngineering for the World We Live InEngineering for the World We Live In
SailsSails Sensible cooling independent of
Primary air delivery.
SailsSailsOperation PrincipleOperation Principle
Increased convection
SailsSailsOperation PrincipleOperation Principle
Chilled SailsChilled Sails
Advantages Design Issues
• Cooling output– 40 to 50 BTUH/FT2 dependent of amount of ceiling used
• Separate air system required
• High cost
• Can not heat
• Need good acoustic treatment to avoid hard spaces
• Many connections
• Aesthetics ?
• Good thermal comfort• Reduced space
requirements– Freely suspended
• Self regulating– Simple controls
• Low noise• Low maintenance
ASHRAEASHRAEEngineering for the World We Live InEngineering for the World We Live In
Cooling & Heating (Ceiling only)
Very High thermal comfort especially on ceilings
Cooling capacity up to 18 Btuh/FT2 floor space (Ceiling - average)
Cooling capacity up to 40 Btuh/FT2 floor space (Sail - average)
Very low ceiling cavities needed, could in installed in a 6” space.
Self regulating simple two position controls
Low noise
Low maintenance
Ceilings & Sails Summary Ceilings & Sails Summary -
ASHRAEASHRAEEngineering for the World We Live InEngineering for the World We Live In
Passive Passive BeamsBeams
Buoyancy driven sensible cooling independent of
Primary air delivery
Passive Chilled BeamsPassive Chilled BeamsOperation PrincipleOperation Principle
Perforated tile
Water coil
Suspension rod
Soffit
Fabric skirt
Passive Chilled BeamsPassive Chilled BeamsAirflow PatternAirflow Pattern
Façade driven coolingFaçade driven cooling
Above the ceiling recessedAbove the ceiling recessed
ExposedExposed
Passive beamsPassive beams
Advantages Design Issues
• Cooling output– 40 to 50 BTUH/FT2
• Separate air system required
• Need High free area ceilings
• Can not heat• Need deep ceiling cavity
and space above coil• Need separate return air
passage for remove primary air volume
• Good thermal comfort• Low terminal velocities• Self regulating
– Simple controls• Low noise• Low maintenance• Ideal ‘top up’ to UFAD
especially at the façade
ASHRAEASHRAEEngineering for the World We Live InEngineering for the World We Live In
Typical Installation
ASHRAEASHRAEEngineering for the World We Live InEngineering for the World We Live In
Cooling only
Good thermal comfort
Cooling capacity up to 50 Btuh/FT2 floor space
Up to 450 BTUH per LF of beam
Reduced ductwork, riser and plant sizesWater transports most of sensible cooling
Self regulating simple two position controls
Low noise
Low maintenance
Passive Beams Summary Passive Beams Summary -
Perforation Free Areas
Are critical to passive beam performance !
Painted ?Painted ?
Usually, perforated free areas are quoted prior to paint application !Usually, perforated free areas are quoted prior to paint application !
Rule of ThumbRule of Thumb
Minimum 1/8” hole, approx 45% free area preferred, any reduction Minimum 1/8” hole, approx 45% free area preferred, any reduction in hole size or free area reduces output therefore it costs you more in hole size or free area reduces output therefore it costs you more because you need more beamsbecause you need more beams
On a recent projectOn a recent project
The tiles were specified 28% free area 1/10” hole. These turned out The tiles were specified 28% free area 1/10” hole. These turned out to be when painted a 1/12” hole which equated to to be when painted a 1/12” hole which equated to
19% free area.19% free area.This reduced the reduced performance by a further 20%This reduced the reduced performance by a further 20%
Passive beams – Passive beams – Perforation beware!Perforation beware!
Passive beams – Return Passive beams – Return air passageair passage
• Passive beams need a return air passage to feed the coil, typically the same area as the coil, split 50-50 along the 2 long sides of the beam.
• As important, the removal of the fresh or conditioned air must have aSeparate return route if the return is via the celling cavity/void.
Better to have a ducted return!
AGENDAAGENDA
• Part 2 – Active systemsPart 2 – Active systems
• Active Chilled BeamsActive Chilled Beams
Part 3 - Reducing EnergyPart 3 - Reducing Energy• Space Humidity concerns• Design Considerations• Water System Design• Savings & LEED
Part 4 - Solutions Part 4 - Solutions • All Air Core• 6 Way• LoFlo• Overall 1st Costs
So What are Chilled So What are Chilled Ceilings & Beams?Ceilings & Beams?
A sensible cooling only device that uses chilled water above the room dew point to remove heat
from the space.
They can be independent of, or combined with, a method of introducing conditioned outside air to
the space to meet the ASHRAE 62 ventilation requirements
Chris LawrenceChris LawrenceVP Sales & Marketing
ASHRAEASHRAEEngineering for the World We Live InEngineering for the World We Live In
Active Beams
Sensible cooling combined with primary air Sensible cooling combined with primary air deliverydelivery
Active Chilled BeamActive Chilled BeamOperation Principle - Horizontal coilOperation Principle - Horizontal coil
Suspended ceiling
Primary air plenum
Primary air nozzles
Heat exchanger
SlabPrimary
air supply
Suspended Ceiling
Active Chilled BeamActive Chilled BeamOperation Principle - Vertical coilsOperation Principle - Vertical coils
Active Chilled BeamActive Chilled BeamAirflow Pattern 2-wayAirflow Pattern 2-way
Active Chilled BeamsActive Chilled Beams2 way2 way
ASHRAEASHRAEEngineering for the World We Live InEngineering for the World We Live In
Active Chilled BeamsActive Chilled Beams1 Way perimeter (Concealed)1 Way perimeter (Concealed)
Thermal ComfortThermal ComfortPerimeter CFDPerimeter CFD
Good air movement throughout the room with
≈ 3-4:1 entrainment ratios
Uniform temperatures andno drafts by thorough mixingof the primary and room air
Active Chilled BeamsActive Chilled Beams1 Way perimeter (Concealed)1 Way perimeter (Concealed)
Active beamsActive beams
Advantages Design Issues
• Cooling output– to 100 Btuh/FT2 , beam
outputs up to 1800 Btuh/LF
• Can be 2 or 4 pipe
• Can heat
• Need more primary air than minimal fresh are, suggest .3 cfm/SF
• Primary air controls dew point
• All services in celling, integrated cooling, ventilation and heating
• Lower pressure than traditional induction systems
• Self regulating
– Simple controls
• Low maintenance
• Fiber tile ceilings
• Lower ceiling cavity, lower slab to slab
Rule # 1Rule # 1
• The Design with the The Design with the fewest number of chilled fewest number of chilled beams will be the lowest beams will be the lowest 11stst cost install, therefore cost install, therefore performance matters.performance matters.
Performance matters
ASHRAEASHRAEEngineering for the World We Live InEngineering for the World We Live In
Reducing Reducing energyenergy
Heat RemovalHeat RemovalActive Chilled Beam Active Chilled Beam
concept
70% of sensible heat removed by chilled
beam water coil
30% of sensible heat removed by air
Airflow requirementreduced by
70%
• On a Mass Flow Rate Basis:-• 1 lbs of chilled water (6°Δt) transports 4x more
cooling energy than 1 lbs of air (20°Δt)
• As water weighs 800 times that of air
• On a Volume Flow Rate Basis:-• 1 FT³ of chilled water transports 1000 more cooling
energy than 1 FT³ of air (20 Δt)
• Transportation Energy
Transportation of a ton of cooling by air requires 7 to 10 times more energy than by chilled water.
Chilled WaterChilled Water
Fan Energy Use in Fan Energy Use in BuildingsBuildings
“Energy Consumption Characteristics of Commercial Building HVAC Systems” - publication prepared for U.S. Department of Energy
70% of sensible heat removed by chilled beam
water coil
Airflow requirement reduced by
70%
Heat Removal Ratio
Rule # 2Rule # 2
• If your not reducing the If your not reducing the air volume in a space by air volume in a space by 25%, you could be 25%, you could be installing a very installing a very expensive diffuserexpensive diffuser
Rule # 3Rule # 3
• Even if your using chilled Even if your using chilled beams on your design, beams on your design, you don’t have to use you don’t have to use them everywhere.them everywhere.
Water = Efficient Water = Efficient TransportTransport
¾” diameter
water pipe
10”
10”
1 Ton of Cooling
requires 550 CFM of air
or
4 GPM of water
‘Water’ is a better cooling medium, than air !
‘Water’ takes less energy to transport
than air !
Chilled Ceilings & Beams do not lower the heat
load of a space, solar gain is still a gain, lights and equipment still give off heat and so do people.
So a room ‘BTU/h is still a BTU/h’, however
.
Room Load is still Room Load is still Room loadRoom load
Only enough ‘‘chilled Water’ chilled Water’ is Chilled to 45°F to dehumidify the reduced primary airflow requirement.
So less energy is used to produce the beams ‘chilled water’
at 58°F - saving energysaving energy
We need less We need less primary air, primary air, making making 100% DOAS ideal and cost 100% DOAS ideal and cost effective, effective, Improving IAQ Improving IAQ & Ventilation effectiveness& Ventilation effectiveness
ASHRAEASHRAEEngineering for the World We Live InEngineering for the World We Live In
Space Space Humidity Humidity ConcernsConcerns
ASHRAEASHRAEEngineering for the World We Live InEngineering for the World We Live In
Independent PublicationsIndependent Publications
Part of the European Commission ‘Energie’ program, in partnership Part of the European Commission ‘Energie’ program, in partnership with COSTIC (France), BSRIA (UK), ISSO (Netherlands) & IDEA with COSTIC (France), BSRIA (UK), ISSO (Netherlands) & IDEA (Spain).(Spain).
Climatic Ceilings - Technical Note: Design CalculationsClimatic Ceilings - Technical Note: Design Calculations
Climatic Ceilings and Chilled beams - Application of low Climatic Ceilings and Chilled beams - Application of low temperature heating and high temperature coolingtemperature heating and high temperature cooling
This years 2012 ASHRAE HVAC This years 2012 ASHRAE HVAC Systems and Equipment publication Systems and Equipment publication covers chilled beam basicscovers chilled beam basics
REHVA REHVA (Federation European Heating & (Federation European Heating &
Ventilation) Ventilation) PublicationPublication
AHRI Test Standard AHRI Test Standard (being worked on) (being worked on)
Passive + 0.5 °C ( + 0.9 °F )
Active
- 1.5 - 1.5 °°C ( - 2.7 C ( - 2.7 °°F)F)
Relative to room air dew point
Extract From Independent Extract From Independent ‘Energie’ Climatic Ceilings‘Energie’ Climatic Ceilings
75˚/50% RH75˚/50% RH
75˚/70% RH75˚/70% RH
58˚ CWS58˚ CWS
64˚ Dew Point
55.1˚ Dew Point
Condensation Condensation ConsiderationConsideration
Condensation after 8.5 hours on a chilled surface intentionally held 7.8F colder than the space DPT. Not one droplet fell under these conditions
Chilled Ceilings in Parallel with Dedicated Outdoor Air Systems: Addressing the Concerns of Condensation, Capacity, and Cost Stanley A. Mumma, Ph.D., P.E.
‘Active Chilled beams could Active Chilled beams could be run at or below the room be run at or below the room dew point, but that’s crazydew point, but that’s crazy’’!!
Be safe, design at 2 to 3F above the dew point and control the moisture
content of the primary air to control the room RH
Rule # 4Rule # 4
• If you can not measure If you can not measure and control the space and control the space humidity, humidity, and your not in the middle of and your not in the middle of
the desertthe desert, don’t use chilled , don’t use chilled beams !beams !
ASHRAEASHRAEEngineering for the World We Live InEngineering for the World We Live In
Design Design ConsiderationsConsiderations
Building SuitabilityBuilding Suitability
Building Characteristics that favor Active Chilled Beams
•Zones with moderate-high sensible load densities‒ Where primary airflows would be significantly higher than
needed for ventilation
•Buildings most affected by space constraints‒ Hi – rises, existing buildings with induction systems
• Zones where the acoustical environment is a key design criterion
•Laboratories where sensible loads are driving airflows as opposed to air change rates
•Buildings seeking LEED or Green Globes certification
Building SuitabilityBuilding Suitability
Characteristics that less favor Active Chilled Beams
•Buildings with operable windows or “leaky” construction
‒ Beams with drain pans could be considered
•Zones with relatively low sensible load densities
•Zones with relatively low sensible heat ratios and low ventilation air requirements
•Zones with high filtration requirements for the re-circulated room air
•Zone with high latent loads
ASHRAEASHRAEEngineering for the World We Live InEngineering for the World We Live In
Water System Water System designdesign
S
T
Secondary chilled water supply to beams
Secondary chilled water return
Supply temperature
monitor
Primary chilled water supply
Primary chilled water return
Heat Exchanger
SCHW Pump
Secondary LoopSecondary Loop
T
To chilled beam zones
Bypass Valve
Chilled waterpump
Dedicated chiller11+ COP
64°F
58°FCooling Tower
Geothermal Loop
Geothermal Heat Pump
Dedicated ChillerDedicated Chiller
District Chilled District Chilled Water Loops Water Loops
• No demand in district loop GPM• Increases main chiller plant COP
Tap into return pipe with heat exchanger and secondary loop
Waterside Waterside EconomizerEconomizer
With mid-high 50ºFs chilled water temperatureserving the Active Chilled Beams
Reduce chiller energy consumption through:
•Using a water side economizer to minimize the chiller operating hours serving the Active Chilled Beams
ASHRAEASHRAEEngineering for the World We Live InEngineering for the World We Live In
Savings Savings & &
LEED LEED
Energy SavingsEnergy SavingsCompared to VAVCompared to VAV
Source Technology Application % Saving*
US Dept. of Energy Report (4/2001) Beams/Radiant Ceilings General 25-30
ASHRAE 2010 Technology Awards Passive Chilled Beams Call Center 41
ACEE Emerging Technologies Report (2009) Active Chilled Beams General 20
ASHRAE Journal 2007 Active Chilled Beams Laboratory 57
SmithGroup Active Chilled Beams Offices 24
*Compared to VAV
Call Center, KentuckyCase Study
• Call center, 350,000 sq ft
• 2200 occupants
• LEED design
• Considered radiant ceilings and passive beam systems
• Article in ASHRAE Journal, December 2009
• Real energy results based on comparison with another building on the same campus
• Energy usage data collected over 1 year
• Electrical energy consumption reduced by 41%
• Natural gas consumption reduced by 24%
Call Center, KentuckyCase Study
First CostsFirst CostsCompared to VAVCompared to VAV
“Energy Consumption Characteristics of Commercial Building HVAC Systems” - publication prepared for U.S.
Department of Energy
• No moving parts
• No filter
• No condensate pumps
• No consumable parts
• Up to 4 year inspection & clean
• Easy maintenance access
MaintenanceMaintenance
• Optimize Energy Performance
- up to 48% (new) or 44% (existing)more efficient than ASHRAE
90.1
(EA Credit 1) - up to 19 points
• Increased Ventilation
- 30% more outdoor air than
ASHRAE 62
(IEQ Credit 2) - 1 point
• Controllability of Systems
- individual temperature control
(IEQ Credit 6.2) - 1 point
• Thermal Comfort
- meet ASHRAE 55
(IEQ Credit 7.1) - 1 point
(Minimum 40 points needed for certification
out of 100 maximum)
LEED CertificationLEED Certification
ASHRAEASHRAEEngineering for the World We Live InEngineering for the World We Live In
Solutions Solutions to reduce costto reduce cost
ASHRAEASHRAEEngineering for the World We Live InEngineering for the World We Live In
All Air CoreAll Air Core
Interior ZonesInterior ZonesInduction DiffuserInduction Diffuser
555 cfm
60ºF
277 cfm
75ºF
277 cfm
48ºF
Lower airflows and fan energy consumption in theinterior VAV system through use of lower temperatureprimary air
- 20% reduction if temperature lowered from 55ºF to 50ºF
- 26% reduction if temperature lowered from 55ºF to 48ºF
Improved comfort through increased air movement in the low load interior zones
Increased latent cooling capacity and improved humidity control
Latent 640 Btuh
Latent 1408 Btuh
2.2 times latent capacity for same sensible capacity with 26% less primary air
ASHRAEASHRAEEngineering for the World We Live InEngineering for the World We Live In
6 Way valve6 Way valve
2 or 4 Pipe 2 or 4 Pipe Chilled Beams?Chilled Beams?
•Higher coil performance
4 pipe performance is compromised
75% Cooling (12 pipes)
25% Heating (4 pipes)
•Fewer or shorter beams•Lower hot water temperatures
90°F for 2 pipe
130°F for 4 pipe
2-Pipe Beams and 2-Pipe Beams and Terminal HeatingTerminal Heating
S
S
T
Terminal Heating Coil
2-Pipe Active Chilled Beams
Chilled Water Supply
Chilled Water Return
Hot Water Supply
Hot Water Return
6-way valve6-way valve
6-way valve6-way valve
• One valve per zone
• 4-pipe to zone then 2-pipe to chilled beams
• Half controls costs
• Increased chilled beam performance
• Increased energy efficiency
6-way valve6-way valve
ASHRAEASHRAEEngineering for the World We Live InEngineering for the World We Live In
LoFloLoFlo
AdvantagesReduced pipeworkHigher system Delta TReduced pumping flow and horse powerIncreased flexibilityEliminate flow control valve and balancing valvesReduced commissioningMultiple water temperaturesIncreased capacity at chilled beam (no 4-pipe req.) Used in conjunction with 6 way valveLMB requires no maintenanceOne LMB for each zone (multiple ACB’s)Simple cartridge replacement
DisadvantagesPower required to each LMBRequires low temperature water at thermal plant
ASHRAEASHRAEEngineering for the World We Live InEngineering for the World We Live In
Overall Overall 11stst cost cost
• New $15.8m facility (original estimate $20m)
• 68,000 ft2, 7 floors
• Consists of labs, lecture halls and classrooms
• LEED Silver Certification
• Completion fall 2011
Viterbo Viterbo
School of Nursing, WISchool of Nursing, WI
HVAC First CostsHVAC First CostsSavings Compared to VAVSavings Compared to VAV
• Smaller AHU’s
• Smaller ductwork
• Controls‒ Simple two position zone valves
• Electrical infrastructure costs‒ Increased pump HP more than offset by reduced fan HP
HVAC First CostsHVAC First CostsIncreases Compared to VAVIncreases Compared to VAV
• More terminals (beams)
• More distribution piping
• More piping insulation‒ Requirement depends on chilled water temperature and dewpoint
Overall HVAC cost increase = $300,000 compared to VAV
Construction CostsConstruction CostsReduced heightReduced height
Overall height reduced by 6’
Floor heights reduced 10”-14”
Construction CostsConstruction CostsSavings due to reduced heightSavings due to reduced height
Building Component Savings
Structural Steel 7,200$ Masonry (int/ext) 97,692$ Fire-Proofing 600$ Steel Studs 22,824$ Air Barrier 8,787$ Insulation 3,424$ Exterior Caulking 1,522$ Curtain Wall 10,500$ Stairs 2,500$ Exterior Drywall 55,249$ Elevators 5,000$ Electrical 30,000$
Total Cost Savings 245,298$
Pricing provided by CD Smith Construction
Overall cost neutral
Viterbo Viterbo
School of Nursing, WISchool of Nursing, WI
Rule # 5Rule # 5
• When budgeting chilled When budgeting chilled beams, consider the beams, consider the overall 1overall 1stst cost, not just cost, not just the Mechanical vs VAV.the Mechanical vs VAV.
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