Active Chilled Beam Technology

Presented by: Matt Green Active Chilled Beam Technology

Section I: Introduction to ACB Technology Types of Chilled Beams ACB Technology Advantages How ACB’s Work How ACB Systems Compare to Other Systems Common Applications of ACB Technology Misapplications of ACB Technology Section II: ACB System Design Considerations DOAS/Airside System Design Chilled Water System Design Heating with ACB’s Controlling ACB Systems Condensation Prevention Agenda

Section I: Introduction to ACB Technology Types of Chilled Beams

Section I: Introduction to ACB Technology Types of Chilled Beams – Active Chilled Beams Cooling and Heating Fresh air supplied through beams Very low acoustic signatures Very high energy efficiency Very high levels of occupant thermal comfort

ACB Technology Advantages Energy conservation Reduced space consumption Reduced maintenance costs Increased comfort levels Section I: Introduction to ACB Technology

Section I: Introduction to ACB Technology How ACB’s Work A) Primary air duct connection (.3-1.2 in. w.c.) B) Primary air plenum Secondary air (room air) Unit mounted coil (2-pipe or 4-pipe configuration) E) Mixed air (Induction ratio range 3:1 – 6:1) F) Discharge air (Cooling: 63-66ºF / Heating 75-85ºF) G) Adjustable mounting brackets

Section I: Introduction to ACB Technology How ACB Systems Compare to Other Systems - VAV First costs for ACB are typically higher than VAV: 5-10% higher Copper pipe largest cost ‘penalty’ for ACB systems PEX piping, good alternative, save cost on branch piping insulation DOAS/AHU & duct costs are lower in ACB systems ACB first costs are trending closer to VAV Operating costs are significantly lower for ACB systems No Maintenance Significant energy savings Reduction in AHU horsepower Increased chiller EER Equipment VAV ACB DOAS/AHU and Fans $285,000 $185,000 Ductwork $260,000 $195,000 Chiller $150,000 $150,000 Copper Piping $55,000 $315,000 Active Chilled Beams $0 $110,000 VAV Units $75,000 $0 Sound Dampers $20,000 $5,000 Temperature Controls $105,000 $130,000 Registers and Diffusers $110,000 $40,000 Total $1,060,000 $1,130,000 Building Sq Footage 50,000 50,000 Cost/Sq Ft. $21 $23

Section I: Introduction to ACB Technology How ACB Systems Compare to Other Systems - FCU First costs for ACB are typically lower than FCU: 5-10% lower Savings on equipment and piping favor ACB systems Operating costs are significantly lower for ACB systems Fan energy savings No maintenance Significant energy savings Chiller EER Equipment FCU ACB DOAS and Fans $185,000 $185,000 Ductwork $170,000 $195,000 Chiller $150,000 $150,000 Copper Piping $420,000 $315,000 Active Chilled Beams $0 $110,000 Fan Coil Units $185,000 $0 Sound Dampers $5,000 $5,000 Temperature Controls $115,000 $130,000 Total $1,230,000 $1,090,000 Building Sq Footage 50,000 50,000 Cost/Sq Ft. $25 $22

Section I: Introduction to ACB Technology How ACB Systems Compare to Other Systems – Energy Efficiency Figure from: Centre For Building Science News, Lawrence Berkeley Laboratory, “Hydronic Radiant Cooling Systems”, Fall 1994. * Figure does not include additional fan energy associated with developing pressure for active chilled beam operation. Flow Cross Section Ratio 1:550 ¾“ diameter Water Pipe The energy that 1 ft 3 of water removes requires 3,400 ft 3 of air! 18“ x 18“ Air Duct

Section I: Introduction to ACB Technology How ACB Systems Compare to Other Systems – Energy Efficiency Operating cost of the chilled water system can significantly be lower for ACB systems due to the ability to use higher leaving chilled water temperatures Improved chiller EER at higher leaving water temperatures Allows for downsizing the nominal tonnage of the chiller while maintaining similar output tonnage Chiller Nominal Tonnage LWT Output Tons kWi EER 250 45 257 319.4 9.6 210 55 257 296.2 10.4 190 60 250 276.1 10.8

Section I: Introduction to ACB Technology Common Applications of ACB Technology High sensible cooling load applications Heat driven laboratories, offices, etc. Sound sensitive applications Libraries, hospitals, universities, etc. Retrofit applications (CAUTION) ACB’s require minimal overhead clearance LEED Applications Superior energy efficiency, individual temperature control, and innovation

Section I: Introduction to ACB Technology Misapplications of ACB Technology Spaces with high ceilings (above 14’) Manufacturing, warehouses, etc. Spaces with high latent loads Indoor pools, gymnasiums, etc. Spaces with uncontrolled humidity Atriums, vestibules, hallways, etc. Spaces with restrictions on recirculated air Class I and Class II hospital areas

Section II: ACB System Design Considerations DOAS/Airside System Design A DOAS is required for the following: Dewpoint control to prevent condensation on the ACB’s Provide minimum ventilation requirement (ASHRAE Std. 62) Must handle 100% of the OA’s latent and sensible load Must handle 100% of the zone’s latent load Induce sufficient airflow through ACB’s to satisfy zone sensible load Positively pressurize building envelope to prevent infiltration

Section II: ACB System Design Considerations DOAS/Airside System Design . There are (2) common DOAS discharge air temperature strategies: Low temperature / low dewpoint strategy (type III desiccant) Not always recommended due to risk of overcooling the space and/or requiring reheat. Consider in applications high space latent loads. “ Neutral air” strategy – thermally neutral but dry air (68-72ºF db / 50-55% RH) Maximizes system efficiency, ACB’s handle ≈100% of space sensible load Free reheat should be incorporated into DOAS unit (i.e. “alpha plate”, sensible wheels, wrap around heat pipe, hot gas reheat ) At summer design conditions, discharge air temperature can be reset colder to satisfy increased loads

Section II: ACB System Design Considerations Chilled Water System Design The ACB’s chilled water supply temperature is dependent on the space’s design dewpoint Supply water temperature should be at least 2-3ºF above the space’s design dewpoint to prevent condensation. Supply water temperature should be as high as possible to take advantage of increased chiller EER and ability to downsize nominal chiller capacity without reduction in output tonnage. Utilizing higher supply water temperatures allows for more available hours for water side economizer. ACB chilled water system temperature rise is lower (typically 6-8ºF) compared to traditional hydronic systems (typically 10-12ºF). The system designer should pay close attention to ACB coil water pressure drop to avoid excessive pump head. Chiller Nominal Tonnage LWT Output Tons kWi EER 250 45 257 319.4 9.6 210 55 257 296.2 10.4 190 60 250 276.1 10.8

Section II: ACB System Design Considerations Chilled Water System Design . DEDICATED CHILLER(S) Two independent chilled water loops Allows higher supply water temperature for ACB chilled water loop Increased chiller EER for ACB water loop Ability to downsize nominal chiller capacity without reduction in output capacity for ACB water loop Higher first cost due to multiple chillers

Section II: ACB System Design Considerations Chilled Water System Design . COMMON CHILLER(S) / MIXING VALVE One common chilled water loop Mixing valve controlled by sensor installed downstream of the discharge of the secondary pump(s) Does not allow for higher supply water temperatures Decreased chiller EER Cannot downsize nominal chiller capacity Should only be considered when ACB chilled water load is significantly less than DOAS load

Section II: ACB System Design Considerations Chilled Water System Design . COMMON CHILLER(S) / HEAT EXCHANGER One common chilled water loop Modulating control valve controlled by sensor installed in outlet side of the water to water heat exchanger Does not allow for higher supply water temperatures Decreased chiller EER Cannot downsize nominal chiller capacity Should only be considered when ACB chilled water load is significantly less than DOAS load; and there is a requirement to isolate primary chilled water loop from the secondary water loop

Section II: ACB System Design Considerations Chilled Water System Design . TRADITIONAL CHILLER(S) / DECOUPLED DOAS DOAS decoupled from chilled water loop Allows higher supply water temperature for ACB chilled water loop Increased chiller EER for ACB water loop Ability to downsize nominal chiller capacity without reduction in output capacity for ACB water loop

Section II: ACB System Design Considerations Chilled Water System Design . GEO CHILLER(S) / DECOUPLED DOAS DOAS decoupled from chilled water loop Allows higher supply water temperature for ACB chilled water loop Increased chiller EER for ACB water loop Ability to downsize nominal chiller capacity without reduction in output capacity for ACB water loop Can utilize advanced geothermal water to water heat pump technology for exceptional energy efficiency Recommended for LEED projects

Section II: ACB System Design Considerations Heating with ACB’s . ACB’s available in 2-pipe in 4-pipe configurations Use of ACB’s for heating is dependent on the building envelope For internal zone or zones with <300 BTU/ft ACB’s are an excellent option For zones between 300-400 BTU/ft, ACB’s can be effective Air directed at 75fpm horizontally towards the window For zones above 400 BTU/ft, ACB’s are not effective Risk of drafts Should use finned tube radiation For low temperature / low dewpoint primary air systems zone reheat should be incorporated to prevent overcooling the space. Typically a reheat coil is installed in the zone’s primary air ductwork Alternate option is to utilize a 4-pipe ACB design

Section II: ACB System Design Considerations Controlling ACB Systems . Chilled water flow control Each zone’s flow is controlled by a single thermostat and a single control valve 2-position zone valves (i.e. on/off control) are typically used Manual isolation valves should be installed Zone Controls Zone Manifold

Section II: ACB System Design Considerations Controlling ACB Systems Primary air flow control can be balanced with the following: Manual balancing damper (i.e. iris type) are used on constant primary airflow systems VAV boxes are used on variable primary airflow systems Should be considered in zones with highly variable latent loads. Demand control ventilation can also be integrated into a VAV control strategy Occupancy sensors can be integrated into a VAV control strategy. When zone is unoccupied, VAV box closes.

Section II: ACB System Design Considerations Condensation Prevention Dewpoint control should be primary consideration in the condensation prevention control strategy Additional control strategies include: The DOAS system should be cycled during unoccupied mode to maintain setback temperature and dewpoint set points. In addition, a “dry out” cycle should be implemented after long periods of unoccupied mode operation (i.e. weekends) Dewpoint sensors can be used to detect then disable the ACB system when a condition where condensation could occur is present. Alternately, moisture sensors on water piping can be used. Window switches can be used to disable the ACB system when a window is opened and ambient conditions will result in condensation

Section II: Summary Benefits of ACB Technology Energy conservation 40-70% less primary air, compared to all air systems 75-100% of the space sensible cooling delivered by water Significant reduction in fan energy Increased EER of chiller Reduced space consumption Smaller overall mechanical footprint, reduced duct work size Increase of space ceiling height Reduced maintenance costs No moving parts No filters at the beam required, beams vacuumed every 5-10 years Increased comfort levels Excellent air distribution, Secondary air temperature close to room temp. Lowe noise level, beam systems typically operate with around 10 dB(A) less noise than traditional VAV systems

Section III: References Dadanco Frequently Asked Questions . Retrieved from: http://www.activechilledbeam.com/chilled_beam_questions.asp Darren Alexander and Mike O’Rourke. Design Considerations for Active Chilled Beams (ASHRAE Journal, 2008, September). Geoffrey P. McMahon. Chilled Beams: The Science of Lab Cooling . Retrieved from: http://www.aeieng.com/downloads/articles/ES%20Jan%20%2009%20Chilled%20Beams.pdf Maija Virta, David Butler, Jonas Graslund, Jaap Hogeling, Erik Lund Kristiansen, Mika Reinikainen, and Gunnar Svensson. REHVA – Chilled Beam Application Guidebook (Federation of European Heating and Air-Conditioning Associations, 2004). Peter Rumsey and John Weale. Chilled Beams in Labs: Eliminating Reheating & Saving Energy on a Budget (ASHRAE Journal, 2007, September) Trox Chilled Beam Design Guide . Retrieved from: http://www.trox.us/usa/service/download_center/structure/technical_documents/air_water_systems/usa_products/leaflets/Chilled_Beam_Design_Guide.pdf

Section III: Summary THANK YOU Questions? Primary Contact Matt Green, Sales Engineer Office: 630-693-0926 Cell: 630-730-4917 Fax: 630-693-0931 [email_address] Secondary Contact Jordan Stiebel, Inside Sales Engineer Office: 630-693-5876 Fax: 630-693-0931 [email_address] www.thermosystemsinc.com

Active Chilled Beam Technology

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Active Chilled Beam Technology