Thermally Active Structures for Green Buildings: Introduction and Designing the System. Golden Gate Chapter, October 16, 2013

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1 Thermally Active Structures for Green Buildings: Introduction and Designing the System Golden Gate Chapter, October 16, 2013 Daniel H. Nall, FAIA, PE, LEED Fellow, BEMP HBDP ASHRAE WILL GIVE YOU THE WORLD This ASHRAE Distinguished Lecturer is brought to you by the Society Chapter Technology Transfer Committee Radiant Energy Seminar - 10/16/2013 1

2 Complete the Distinguished Lecturer Event Summary Critique CTTC needs your feedback to continue to improve the DL Program Distribute the DL Evaluation Form to all attendees Collect at the end of the meeting Compile the attendee rating on the Event Summary Critique Send the completed Event Summary Critique to your CTTC RVC and ASHRAE Headquarters Forms are available at: BECOME A FUTURE LEADER IN ASHRAE WRITE THE NEXT CHAPTER IN YOUR CAREER ASHRAE Members who attend their monthly chapter meetings become leaders and bring information and technology back to their job. YOU ARE NEEDED FOR: Membership Promotion Research Promotion Student Activities Chapter Technology Transfer Technical Committees Find your Place in ASHRAE! Visit Radiant Energy Seminar - 10/16/2013 2

3 Why Rock the Boat Disadvantages of Common HVAC Systems Temperature, Humidity, Ventilation all controlled by a single Sensor Much Energy Expended in Moving Air Around Energy Expended for Conditioning Areas where People Aren t Poor Comfort Control due to Space and Surface Temperature Variation Why Radiant Heating/Cooling Avoidance of Extensive Ductwork for Distribution of Conditioning Medium Incorporation of the Thermal Mass of the Structure Into the Driving Force of the Conditioning System Improved Human Comfort Removal of Solar Heat Gain Directly From Mass Without Additional Air Flow Reduced Heat Transport Energy Using Water Compared with Air Radiant Energy Seminar - 10/16/2013 3

4 Radiant Heating/Cooling Sunspace Conditioning Controlling the Temperature of the Building Structural Mass instead of the Air Dedicated Ventilation/Dehumidification System Polyethylene Tubing Imbedded in Slab Circulates Hot or Cool Water to Alter Slab Temperature Direct Removal of Absorbed Solar Heat gain from Floor Slab Radiant Heating Cooling Issues Ventilation Dehumidification Changeover from Heating to Cooling Condensation Avoidance Capacity Control Construction Radiant Energy Seminar - 10/16/2013 4

5 Applicable Standards for Performance Testing British Standards Institute o ISO 11855: 2012 Building environment design. Design, dimensioning, installation and control of embedded radiant heating and cooling systems DIN o EN Radiant Heating Floor Schematics Radiant Energy Seminar - 10/16/2013 5

6 Radiant Heating Cooling Design Tools Two Dimensional Floor Heat Transfer Shortwave Radiant Fluxes on Floor Room Thermal Stratification Radiant Coupling between Room Surfaces Maria s Radiant Floor Modeller Radiant Energy Seminar - 10/16/2013 6

7 Solar Patch Projection July 4 pm February 4 pm July 12 pm 13 Temperature and Velocity Distribution 5 Ft above Floor Vertical 14 Radiant Energy Seminar - 10/16/2013 7

8 Computational Fluid Dynamics Pier 1: Radiant Floor, Bay Heat Exchange Radiant Energy Seminar - 10/16/2013 8

9 IBT Headquarters: Radiant Cooling, Displacement Ventilation Radiant Heating/Cooling: Repsol Winter Garden - Architectural and CFD Images Radiant Energy Seminar - 10/16/2013 9

10 Bangkok International Airport Bangkok, Thailand Bangkok International Airport Bangkok, Thailand Radiant Energy Seminar - 10/16/

11 Pier One San Francisco, CA Pier One San Francisco, CA Radiant Energy Seminar - 10/16/

12 Hearst Tower: Radiant Heating/ Cooling Lobby Floor Radiant Energy Seminar - 10/16/

13 Hearst Headquarters Radiant Heating/Cooling Floor Geometry and CFD Results Hearst Headquarters Radiant Heating/Cooling Floor - Displacement Ventilation Radiant Energy Seminar - 10/16/

14 Lobby Temperature Sections Lobby Temperature Sections Radiant Energy Seminar - 10/16/

15 Lobby Temperature Sections Hearst Headquarters Chilled Water Feature Radiant Floor Tubing Radiant Energy Seminar - 10/16/

16 Dartmouth College McLaughlin Hall (2006) Heating Geometry Cooling Dartmouth College McLaughlin Hall (2006) Radiant Floor CFD Analysis Heating Heating Radiant Energy Seminar - 10/16/

17 The William Jefferson Clinton Presidential Center The William Jefferson Clinton Presidential Center Radiant Energy Seminar - 10/16/

18 AIR MOTION REPRESENTATION William Jefferson Clinton Presidential Center - LEED Silver Computational Fluid Dynamics Studies of Museum Area - Temperature, Flow and Ventilative Effectiveness The William Jefferson Clinton Presidential Center Radiant Energy Seminar - 10/16/

19 Syracuse University School of Management Grand Hall Syracuse School of Management Grand Hall Radiant Energy Seminar - 10/16/

20 Syracuse School of Management Grand Hall Radiant Floor Tubing Syracuse School of Management Grand Hall Team CFD analysis Radiant Energy Seminar - 10/16/

21 Gaylord National Harbor Hotel Suitland, MD Gaylord National Harbor Hotel Radiant Floor Piping Radiant Energy Seminar - 10/16/

22 Gaylord National Harbor Hotel CFD Analyses for Cooling Gaylord National Harbor Hotel 44 Radiant Energy Seminar - 10/16/

23 The Newseum, Washington, DC Thermally Active Floor and Skywalks 45 World Financial Center, Wintergarden Pavilion, New York Thermally Active Floor and Displacement Ventilation 46 Radiant Energy Seminar - 10/16/

24 Radiant/Heating Cooling Guidelines Principles of Design The system does not provide ventilation or dehumidification. A conditioned air system is required to provide these functions. The system is a low temperature difference, large active area conditioning system, so highly accurate temperature control is not required for comfort maintenance. A chilled floor enhances stratification, providing greater comfort where the people are. A heated floor minimizes stratification, also minimizing overheating high in the space. Chilled floors are most effective at removing solar heat gain as it is absorbed into the slab, reducing air flow necessary for cooling. System does not require quick response because direct control of building mass in the space precludes rapid change of load magnitude. Radiant/Heating Cooling Guidelines Principles of Design Floor is controlled to be the right temperature for a given space condition. Floor is controlled by resetting set-point temperature Heating cooling changeover should be a rare event and controlled to avoid driving the floor from one mode to another Variable flow control (multi-zone pulsed constant flow) with constant inlet temperature (in a mode) allows inexpensive individual zone control. Constant flow with variable inlet temperature requires a pump for each zone. Time constant of floor temperature reset stimulus should be longer than that of the floor itself. Floor capacity is dependent on absorbed solar radiation. Solar radiation absorbed by non-active surfaces must be removed by alternate means. Radiant Energy Seminar - 10/16/

25 Radiant/Heating Cooling Guidelines Design Process Calculate cooling loads with both radiant and convective components and locate them within the room volume. Explicitly calculate solar heat gain patches on floor for size, location and intensity. Separate solar heat gain absorbed by windows from that transmitted through windows. Use two dimensional heat transfer calculations to determine temperature of solar irradiated radiant floor. Incorporate floor finish and topping slab conductances in calculation. Calculate for range of flow rates and inlet temperatures. Use CFD analysis with calculated radiant and convective internal heat gains and solar heat gain patches calculated above Configure radiant loop zoning to match pattern of solar heat gain Radiant/Heating Cooling Guidelines Radiant System Layout 1 Configure isolated radiant loop with heating and cooling heat exchangers to minimize fouling in the tubing. Magnitude of space and use will determine if flow modulation is applied to individual zone loops or to manifolds for flow temperature control. Establish minimum zoning based upon use and solar exposure. Layout tubing in double serpentine pattern to minimize temperature differences across the floor. Locate manifolds to minimize home run distance to controlled floor area. Layout loops based on 300 ft. roll size. Base loop zoning size on centerline tubing spacing and homerun length. Radiant Energy Seminar - 10/16/

26 Radiant/Heating Cooling Guidelines Radiant System Layout 2 Locate floor temperature sensors to be representative of zone. Use separate heat exchangers for heating and cooling or single heat exchanger with four-pipe change-over valving Control temperature of heat exchanger secondary outlet temperature by modulating primary flow volume. Allow variable flow in radiant loop with variable speed circulating pump or pressure controlled bypass. Compare cooling diversity flow requirements with non-diverse heating flow requirements to size pumps and heat exchangers. Max heating may take on gpm per loop. Max cooling takes up to 2.0 gpm per loop, but is diverse because of solar patches. Radiant/Heating Cooling Guidelines Measures to Improve Comfort Outside air system configured to provide adequate ventilation, well distributed around the space. Limit temperature range of floor between 68 DegF and 80 DegF Limit temperature range of displacement ventilation between 66 DegF and 85 DegF Limit velocity through displacement diffusers to 60 fpm. Zone floor to accommodate solar shadowing patterns. Control floor to offset impact of cold surfaces on mean radiant temperature Radiant Energy Seminar - 10/16/

27 Acknowledgements: St. Meinrad Archabbey Church Architect Woollen Molzan Partners, Indianapolis, IN Building Services Engineers Roger Preston + Partners, Atlanta Virginia Hand Callaway Center Architect Robert Lamb Hart, NYC Building Services Engineers Roger Preston + Partners, Atlanta and Creative Engineering Design, Atlanta IBT Headquarters Architect Murphy Jahn, Chicago, IL Building Services Engineers Flack + Kurtz, San Francisco, CA Hearst Headquarters Architect Foster and Partners, London, UK Building Services Engineers Flack + Kurtz, NYC Dartmouth College McLaughlin Residences Architect Bruner Cott, Boston, MA, and Moore, Ruble, Yudell, Architects, Santa Monica, CA Building Services Engineers Flack + Kurtz, NYC William Jefferson Clinton Library Architect Polshek Partners., New York, NY Building Services Engineers Flack + Kurtz, NYC Cromwell Architects, Engineers, Little Rock, AR Pier 1 Architect SMWM Architects, San Francisco, CA Building Services Engineers Flack + Kurtz, San Francisco, CA Gaylord National Harbor Hotel Architect Gensler Building Services Engineer WSP Flack + Kurtz, NYC Syracuse University School of Management Architect F X Fowle, NYC Building Services Engineers Flack + Kurtz, NYC SAP Corporate Headquarters Architect F X Fowle, NYC Building Services Engineers WSP Flack + Kurtz, NYC World Financial Center Wintergarden Architect Pelli, Clarke, Pelli Building Services Engineers WSP Flack + Kurtz, NYC Thanks Daniel H. Nall, FAIA, PE, LEED Fellow, HBDP, BEMP Thornton Tomasetti 51 Madison Avenue New York, NY dnall@thorntontomasetti.com Radiant Energy Seminar - 10/16/