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Chris Lawrence VP Sales & Marketing. AGENDA So what areSo what are Chilled Ceilings & Beams ? Part 1 – Passive SystemsPart 1 – Passive Systems Chilled.

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Presentation on theme: "Chris Lawrence VP Sales & Marketing. AGENDA So what areSo what are Chilled Ceilings & Beams ? Part 1 – Passive SystemsPart 1 – Passive Systems Chilled."— Presentation transcript:

1 Chris Lawrence VP Sales & Marketing

2 AGENDA So what areSo what are 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 - SolutionsPart 4 - Solutions All Air Core 6 Way LoFlo Overall 1 st Costs

3 So What are Chilled 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

4 ASHRAE Engineering for the World We Live In Chilled Ceilings Radiant & Convective sensible cooling independent of Primary air delivery

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7 Chilled Ceiling Radiant Effect 76°F Dry Bulb 74°F radiant temperature (black bulb)

8 Chilled Ceilings AdvantagesDesign Issues Low cooling output –20 to 25 BTUH/FT 2 100% coverage –14 to 18 BTUH/FT 2 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

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10 ASHRAE Engineering for the World We Live In Sails Sensible cooling independent of Primary air delivery.

11 Sails Operation Principle

12 Increased convection Sails Operation Principle

13 Chilled Sails AdvantagesDesign Issues Cooling output –40 to 50 BTUH/FT 2 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

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15 ASHRAE Engineering for the World We Live In Cooling & Heating (Ceiling only) Very High thermal comfort especially on ceilings Cooling capacity up to 18 Btuh/FT 2 floor space (Ceiling - average) Cooling capacity up to 40 Btuh/FT 2 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 -

16 ASHRAE Engineering for the World We Live In PassiveBeams Buoyancy driven sensible cooling independent of Primary air delivery

17 Passive Chilled Beams Operation Principle Perforate d tile Water coil Suspension rod Soffit Fabric skirt

18 Passive Chilled Beams Airflow Pattern

19 Façade driven cooling

20 Above the ceiling recessed

21 Exposed

22 Passive beams AdvantagesDesign Issues Cooling output –40 to 50 BTUH/FT 2 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

23 ASHRAE Engineering for the World We Live In Typical Installation

24 ASHRAE Engineering for the World We Live In Cooling only Good thermal comfort Cooling capacity up to 50 Btuh/FT 2 floor space Up to 450 BTUH per LF of beam Reduced ductwork, riser and plant sizes Water transports most of sensible cooling Self regulating simple two position controls Low noise Low maintenance Passive Beams Summary Passive Beams Summary -

25 Perforation Free Areas Are critical to passive beam performance ! Painted ? Usually, perforated free areas are quoted prior to paint application ! Rule of Thumb Minimum 1/8 hole, approx 45% free area preferred, any reduction in hole size or free area reduces output therefore it costs you more because you need more beams On a recent project The tiles were specified 28% free area 1/10 hole. These turned out to be when painted a 1/12 hole which equated to 19% free area. This reduced the reduced performance by a further 20% Passive beams – Perforation beware!

26 Passive beams – Return air 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 a Separate return route if the return is via the celling cavity/void. Better to have a ducted return!

27 AGENDA Part 2 – Active systemsPart 2 – Active systems Active Chilled BeamsActive Chilled Beams Part 3 - Reducing Energy Space Humidity concerns Design Considerations Water System Design Savings & LEED Part 4 - Solutions All Air Core 6 Way LoFlo Overall 1 st Costs

28 So What are Chilled 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

29 Chris Lawrence VP Sales & Marketing

30 ASHRAE Engineering for the World We Live In Active Beams Sensible cooling combined with primary air delivery Sensible cooling combined with primary air delivery

31 Active Chilled Beam Operation Principle - Horizontal coil Suspended ceiling Primary air plenum Primary air nozzles Heat exchanger

32 Slab Primary air supply Suspended Ceiling Active Chilled Beam Operation Principle - Vertical coils

33 Velocity Streamlines

34 Active Chilled Beam Airflow Pattern 2-way

35 Active Chilled Beams 2 way

36 Active Chilled Beams Exposed -2 way

37 Active Chilled Beams Perimeter - 1 way

38 ASHRAE Engineering for the World We Live In Active Chilled Beams 1 Way perimeter (Concealed)

39 Thermal Comfort Perimeter CFD Good air movement throughout the room with 3-4:1 entrainment ratios Uniform temperatures and no drafts by thorough mixing of the primary and room air

40 Active Chilled Beams 1 Way perimeter (Concealed)

41 Active beams AdvantagesDesign Issues Cooling output –to 100 Btuh/FT 2, 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

42 Rule # 1 The Design with the fewest number of chilled beams will be the lowest 1 st cost install, therefore performance matters.The Design with the fewest number of chilled beams will be the lowest 1 st cost install, therefore performance matters.

43 Performance matters

44 ASHRAE Engineering for the World We Live In Reducing energy

45 Heat Removal Active Chilled Beam Heat Removal Active Chilled Beam concept 70% of sensible heat removed by chilled beam water coil 30% of sensible heat removed by air Airflow requirement reduced by 70%

46 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 Water

47 U.S. Energy Consumption Courtesy of USGBC

48 U.S. Energy Consumption Courtesy of USGBC

49 Fan Energy Use in Buildings Energy Consumption Characteristics of Commercial Building HVAC Systems - publication prepared for U.S. Department of Energy

50 70% of sensible heat removed by chilled beam water coil Airflow requirement reduced by 70% Heat Removal Ratio

51 Rule # 2 If your not reducing the air volume in a space by 25%, you could be installing a very expensive diffuserIf your not reducing the air volume in a space by 25%, you could be installing a very expensive diffuser

52 Rule # 3 Even if your using chilled beams on your design, you dont have to use them everywhere.Even if your using chilled beams on your design, you dont have to use them everywhere.

53 Water = Efficient Transport ¾ diameter water pipe 10 1 Ton of Cooling requires 550 CFM of air or 4 GPM of water

54 Water is a better cooling medium, than air ! Water takes less energy to transport than air !

55 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 Room Load is still Room load

56 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 saving energy at 58 ° F - saving energy

57 We need less primary air, making 100% DOAS ideal and cost effective, Improving IAQ & Ventilation effectiveness

58 ASHRAE Engineering for the World We Live In Space Humidity Concerns

59 ASHRAE Engineering for the World We Live In Independent Publications Part of the European Commission Energie program, in partnership with COSTIC (France), BSRIA (UK), ISSO (Netherlands) & IDEA (Spain). Climatic Ceilings - Technical Note: Design Calculations Climatic Ceilings and Chilled beams - Application of low temperature heating and high temperature cooling This years 2012 ASHRAE HVAC Systems and Equipment publication covers chilled beam basics REHVA (Federation European Heating & Ventilation) Publication AHRI Test Standard (being worked on)

60 Passive + 0.5 °C ( + 0.9 °F ) Active - 1.5 °C ( - 2.7 °F) Relative to room air dew point Extract From Independent Energie Climatic Ceilings

61 75˚/50% RH 75˚/70% RH 58˚ CWS 64˚ Dew Point 55.1˚ Dew Point

62 Condensation Considerations 75ºF db room design temperature at 50% relative humidity 55.1ºF dew point temperature Theoretically condensation will form on the coil when the chilled water temperature is 55ºF. In reality at this room design condition, condensation in the form of droplets will not begin to form until the water temperature is 52-53ºF. Apparent room dew point is 2-3ºF lower due to insulating effect of a water film on coil fins

63 Condensation Consideration 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.

64 Active Chilled beams could be run at or below the room dew point, but thats crazy!Active Chilled beams could be run at or below the room dew point, but thats 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

65 Rule # 4 If you can not measure and control the space humidity, and your not in the middle of the desert, dont use chilled beams !If you can not measure and control the space humidity, and your not in the middle of the desert, dont use chilled beams !

66 ASHRAE Engineering for the World We Live In Design Considerations

67 Building 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

68 Building 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

69 Required Design Data Room Design Conditions Room Sensible Cooling Loads Room Latent Cooling Loads Room Heating Loads (if used for heating) Infiltration Loads Minimum Outside Air Quantity per Zone Secondary Chilled Water Conditions and Flow Primary Air Conditions and Inlet Pressure Desired Room Air Change Rate (if required) Spatial Considerations/Constraints Room layout/Drawings Unit models desired

70 Role of the Primary Air Ventilate the occupants according to ASHRAE 62 Handle all of the latent load in the space Primary air is only source of latent heat removal Create induction through chilled beam Pressurize the building

71 Primary Air Design Central AHU sized to handle: sensible and latent cooling/heating of the ventilation air portion of the sensible internal cooling/heating loads AND all of the internal and infiltration latent loads Primary air delivered continuously to the chilled beams VAV primary air can be considered for the perimeter if the sensible loads are high Chilled beam water coils provide additional sensible cooling/heating to control zones

72 ASHRAE Engineering for the World We Live In Water System design

73 CHW System Design Options Secondary loop Tap into district CHW loop Heat exchanger into return – no GPM demand Can increase main plant efficiency Dedicated chiller & DX Dehumidification by DX AHU Significantly increased COP - 11+ Twin chillers One for AHUs – 6 COP One for chilled beam circuit – 11+ COP

74 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 Loop

75 T To chilled beam zones Bypass Valve Chilled water pump Dedicated chiller 11+ COP 64°F 58°F Cooling Tower Geothermal Loop Geothermal Heat Pump Dedicated Chiller

76 District Chilled Water Loops No demand in district loop GPM Increases main chiller plant COP Tap into return pipe with heat exchanger and secondary loop

77 Waterside Economizer With mid-high 50ºFs chilled water temperature serving 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

78 Reverse Return Pipe Design S T

79 Boiler Efficiency Lower Hot Water Temp Hot water typically 100-130F Reduce boiler energy consumption by maximizing efficiency of a condensing boiler through very low return water temperatures Use of water to water heat pumps (KN boiler efficiency chart courtesy of Hydrotherm)

80 ASHRAE Engineering for the World We Live In Savings & LEED

81 Energy Savings Compared to VAV

82 Call Center, Kentucky Case Study Call center, 350,000 sq ft 2200 occupants LEED design Considered radiant ceilings and passive beam systems Article in ASHRAE Journal, December 2009

83 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, Kentucky Case Study

84 First Costs Compared to VAV Energy Consumption Characteristics of Commercial Building HVAC Systems - publication prepared for U.S. Department of Energy

85 No moving parts No filter No condensate pumps No consumable parts Up to 4 year inspection & clean Easy maintenance accessMaintenance

86 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 Certification

87 ASHRAE Engineering for the World We Live In Solutions to reduce cost

88 ASHRAE Engineering for the World We Live In All Air Core

89 When the sensible load densities in the interior zones are relatively low, the zone sizes large and the first cost of an Active Chilled Beam system is an issue consider: A single duct VAV interior system in the low sensible load density interior zones An Active Chilled Beam perimeter system in the high sensible load density perimeter zones Low supply air temperature to the single duct VAV with induction diffusers to increase the supply air temperature This needs separate air handers for perimeter & internal/core areas Active Chilled Beam Low Cost Core Solution

90 Interior Zones Induction Diffuser 555 cfm 60ºF 277 cfm 75ºF 277 cfm 48ºF

91 Lower airflows and fan energy consumption in the interior VAV system through use of lower temperature primary 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

92 Latent 640 Btuh Latent 1408 Btuh 2.2 times latent capacity for same sensible capacity with 26% less primary air

93 ASHRAE Engineering for the World We Live In 6 Way valve

94 4-pipe flexibility at 2-pipe cost 6-way valve

95 2 or 4 Pipe Chilled Beams? 2 or 4 Pipe 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

96 2-Pipe Beams and Terminal Heating S S T Terminal Heating Coil 2-Pipe Active Chilled Beams Chilled Water Supply Chilled Water Return Hot Water Supply Hot Water Return

97 6-way valve

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99 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 valve

100 ASHRAE Engineering for the World We Live In LoFlo

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105 Advantages Reduced pipework Higher system Delta T Reduced pumping flow and horse power Increased flexibility Eliminate flow control valve and balancing valves Reduced commissioning Multiple water temperatures Increased capacity at chilled beam (no 4-pipe req.) Used in conjunction with 6 way valve LMB requires no maintenance One LMB for each zone (multiple ACBs) Simple cartridge replacement

106 Disadvantages Power required to each LMB Requires low temperature water at thermal plant

107 ASHRAE Engineering for the World We Live In Overall 1 st cost

108 New $15.8m facility (original estimate $20m) 68,000 ft2, 7 floors Consists of labs, lecture halls and classrooms LEED Silver Certification Completion fall 2011Viterbo School of Nursing, WI

109 HVAC First Costs Savings Compared to VAV Smaller AHUs Smaller ductwork Controls Simple two position zone valves Electrical infrastructure costs Increased pump HP more than offset by reduced fan HP

110 HVAC First Costs Increases 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

111 Construction Costs Reduced height Overall height reduced by 6 Floor heights reduced 10-14

112 Construction Costs Savings due to reduced height Pricing provided by CD Smith Construction Overall cost neutral

113 Viterbo School of Nursing, WI

114 Rule # 5 When budgeting chilled beams, consider the overall 1 st cost, not just the Mechanical vs VAV.When budgeting chilled beams, consider the overall 1 st cost, not just the Mechanical vs VAV.

115 www.dadanco.com


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