Chris Lawrence VP Sales & Marketing

AGENDA Chilled Ceilings & Beams ? Part 1 – Passive Systems So what are Chilled Ceilings & Beams ? Part 1 – Passive Systems Chilled Ceilings Chilled Sails Passive Beams Part 2 – Active systems Active 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 1st Costs

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

Radiant & Convective sensible cooling independent of Chilled Ceilings Radiant & Convective sensible cooling independent of Primary air delivery

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

Chilled Ceilings Advantages Design Issues Excellent thermal comfort Can Heat Reduced space requirements Will fit into 6-8” cavity Self regulating Simple controls Low noise Low maintenance 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

Sensible cooling independent of Sails Sensible cooling independent of Primary air delivery.

Sails Operation Principle

Sails Operation Principle Increased convection

Chilled Sails Advantages Design Issues Good thermal comfort Reduced space requirements Freely suspended Self regulating Simple controls Low noise Low maintenance 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 ?

Ceilings & Sails Summary - 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

Buoyancy driven sensible cooling independent of Passive Beams Buoyancy driven sensible cooling independent of Primary air delivery

Passive Chilled Beams Operation Principle Perforated tile Water coil Suspension rod Soffit Fabric skirt

Passive Chilled Beams Airflow Pattern

Façade driven cooling

Above the ceiling recessed

Exposed

Passive beams Advantages Design Issues Good thermal comfort Low terminal velocities Self regulating Simple controls Low noise Low maintenance Ideal ‘top up’ to UFAD especially at the façade 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

Typical Installation

Passive Beams Summary - 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 sizes Water transports most of sensible cooling Self regulating simple two position controls Low noise Low maintenance

Passive beams – Perforation beware! Perforation Free Areas Are critical to passive beam performance ! Painted ? Usually, perforated free areas are quoted prior to paint application ! 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% 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

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!

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

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

Chris Lawrence VP Sales & Marketing

Sensible cooling combined with primary air delivery Active Beams Sensible cooling combined with primary air delivery

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

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

Velocity Streamlines

Active Chilled Beam Airflow Pattern 2-way

Active Chilled Beams 2 way

Active Chilled Beams Exposed -2 way

Active Chilled Beams Perimeter - 1 way

Active Chilled Beams 1 Way perimeter (Concealed)

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

Active Chilled Beams 1 Way perimeter (Concealed)

Active beams Advantages Design Issues 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 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

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

Performance matters

Reducing energy

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

Chilled Water 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.

U.S. Energy Consumption Courtesy of USGBC

U.S. Energy Consumption Courtesy of USGBC

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

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

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

Rule # 3 Even if your using chilled beams on your design, you don’t have to use them everywhere.

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

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

So a room ‘BTU/h is still a BTU/h’, however Room Load is still Room load 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 .

Only enough ‘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 energy

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

Space Humidity Concerns

REHVA (Federation European Heating & Ventilation) Publication Independent Publications 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) 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

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

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

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. Apparent room dew point is 2-3ºF lower due to insulating effect of a water film on coil fins 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.

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.

‘Active Chilled beams could be run at or below the room dew 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 64

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

Design Considerations

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

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

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

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

Primary Air Design Central AHU sized to handle: AND 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

Water System design

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 AHU’s – 6 COP One for chilled beam circuit – 11+ COP

Secondary Loop Supply temperature monitor Secondary chilled water supply to beams T Primary chilled water supply S SCHW Pump Heat Exchanger Secondary chilled water return Primary chilled water return

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

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

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

Reverse Return Pipe Design

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)

Savings & LEED

Energy Savings Compared to VAV

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

Call Center, Kentucky Case Study 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%

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

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

(Minimum 40 points needed for certification out of 100 maximum) LEED Certification 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)

Solutions to reduce cost

All Air Core

Active Chilled Beam Low Cost Core Solution 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: An Active Chilled Beam perimeter system in the high sensible load density perimeter zones A single duct VAV interior system in the low sensible load density interior 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

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

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

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

6 Way valve

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

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

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

6-way valve

6-way valve

6-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

LoFlo

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 ACB’s) Simple cartridge replacement

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

Overall 1st cost

Viterbo School of Nursing, WI 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

HVAC First Costs Savings 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 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

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

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

Viterbo School of Nursing, WI

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

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