THERMALLY ACTIVE STRUCTURES FOR GREEN BUILDINGS

Transcription

1 Syska Hennessy Group J366 THERMALLY ACTIVE STRUCTURES FOR GREEN BUILDINGS TASGB2015 Daniel H. Nall, PE, FAIA, FASHRAE, LEED Fellow, BEMP, HPDP Date

2 ASHRAE is a Registered Provider with The American Institute of Architects Continuing Education Systems. Credit earned on completion of this program will be reported to CES Records for AIA members. Certificates of Completion for non-aia members are available on request. This program is registered with the AIA/CES for continuing professional education. As such, it does not include content that may be deemed or construed to be an approval or endorsement by the AIA of any material of construction or any method or manner of handling, using, distributing, or dealing in any material or product. Questions related to specific materials, methods, and services will be addressed at the conclusion of this presentation.

3 Approved for: 1 THERMALLY ACTIVE STRUCTURES FOR GREEN BUILDINGS By ASHRAE General CE hours 0 LEED-specific hours GBCI cannot guarantee that course sessions will be delivered to you as submitted to GBCI. However, any course found to be in violation of the standards of the program, or otherwise contrary to the mission of GBCI, shall be removed. Your course evaluations will help us uphold these standards. Course ID:

4 Copyright Materials This presentation is protected by US and International Copyright laws. Reproduction, distribution, display and use of the presentation without written permission of the speaker is prohibited. Syska Hennessy Group Syska Hennessy Group 2015

5 Course Description Thermally active structure is an evolving strategy that has become a popular system in green buildings. Originally implemented for heating only, as radiant heating floors, this strategy has, over the past 20 years been implemented also as a cooling strategy. The addition of cooling capability adds a number of design constraints and potential operational problems to the successful implementation of the system. This presentation explores the many design, construction and operational issues of thermally active heating and cooling structures. Issues addressed include Most effective applications of the technology Design tools Case studies of successful implementations Design issues Construction issues Constraints and limitations How-to tips

6 Learning Objectives At the end of the this course, participants will be able to: 1. Identify projects that might be appropriate for thermally active structures and which might not be appropriate. 2. Recognize design issues for this technology and design tools that can help identify and overcome these issues. 3. Recognize construction issues for this technology and learn how to avoid them. 4. Understand how the technology is implemented in different types of buildings based upon presentation of successful case studies.

7 ASHRAE WILL GIVE YOU THE WORLD This ASHRAE Distinguished Lecturer is brought to you by the Society Chapter Technology Transfer Committee

8 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:

9 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

10 THERMALLY ACTIVE STRUCTURES FOR GREEN BUILDINGS 20/03/2016

11 WHY RADIANT HEATING/COOLING Reduction of ductwork and air handling unit size to meet space loads Incorporation of the thermal mass of the structure into the driving force of the conditioning system Improved human comfort through MRT control Removal of solar heat gain directly from mass without additional air flow Separating space temperature control from humidity control Reduced heat transport energy using water compared with air Reduction in energy expended for conditioning areas where people aren t 20/03/

12 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 20/03/

13 RADIANT HEATING/COOLING ISSUES Ventilation Dehumidification Changeover from Heating to Cooling Condensation Avoidance Capacity Control Construction 20/03/

14 RADIANT HEATING FLOOR SCHEMATICS 20/03/

15 DARTMOUTH MCLAUGHLIN TUBING INSTALLATION 20/03/

16 RADIANT HEATING/COOLING DESIGN TOOLS Two Dimensional Floor Heat Transfer Shortwave Radiant Fluxes on Floor Room Thermal Stratification Radiant Coupling between Room Surfaces 20/03/

17 MARIA S RADIANT FLOOR MODELLER 20/03/

18 COMPUTATIONAL FLUID DYNAMICS 20/03/

19 ST. MEINRAD ARCHABBEY CHURCH 20/03/

20 ST. MEINRAD ARCHABBEY CHURCH Built circa 1900, Gothic church construction 75 foot high nave, 30 ft. high aisles 12,000 square foot floor plate 500 persons for holy day services Daily usage at low occupancy Groin vault roofs and bearing wall construction precluded overhead air 20/03/

21 ST. MEINRAD ARCHABBEY CHURCH DESIGN APPROACH Radiant heating/cooling floor Perimeter displacement ventilation Floor temperature control from wall sensor VAV air control by space air sensor Large displacement diffusers surround entries Return air bypass air handling unit for dehumidification and leaving temperature 20/03/

22 ST. MEINRAD ARCHABBEY CHURCH Existing Heating Scheme 20/03/

23 ST. MEINRAD CHURCH Computational Fluid Dynamics Images: Cooling and Heating with Radiant Floor Displacement, No Radiant Floor; Cooling Radiant Floor; Heating Displacement, Radiant Floor; Cooling 20/03/

24 ST. MEINRAD ARCHABBEY CHURCH 2 nd Generation CFD Finite volume modeling 20/03/

25 ST. MEINRAD ARCHABBEY CHURCH Supply and Return Hydronic Manifolds for Radiant Floor 20/03/

26 ST. MEINRAD ARCHABBEY CHURCH Radiant Floor Piping on Insulation 20/03/

27 ST. MEINRAD ARCHABBEY CHURCH Displacement Diffusers in fascia of benches 20/03/

28 ST. MEINRAD ARCHABBEY CHURCH At Crossing Looking Toward Apse 20/03/

29 ST. MEINRAD ARCHABBEY CHURCH Nave looking Toward Entry 20/03/

30 ST. MEINRAD ARCHABBEY CHURCH CAVEATS Should have used CO2 sensors for demand controlled ventilation Maximum velocity through displacement diffusers Fan operation during chiller plant shut-down season Ventilation of enclosed choir carrels Facilities manager and monks very pleased with comfort and operation 20/03/

31 VIRGINIA HAND CALLAWAY DISCOVERY CENTER Callaway Gardens, GA 20/03/

32 VIRGINIA HAND CALLAWAY DISCOVERY CENTER 34,000 sq. ft. floor area Middle Georgia location Multi-use program Educational component Peak crowd of 200 persons Large shaded glazed area Variable occupancy 20/03/

33 CALLAWAY DISCOVERY CENTER DESIGN APPROACH Conventional ventilation in closed areas Radiant heating/cooling floor in circulation areas Air flow from closed areas is thru circulation space VAV air control by space air sensor Demand controlled ventilation with CO2 sensors in return air Reverse cycle heat pump with lake heat exchangers 20/03/

34 VIRGINIA HAND CALLAWAY DISCOVERY CENTER Siting at lake s edge; exterior sun-shading 20/03/

35 VIRGINIA HAND CALLAWAY DISCOVERY CENTER Circulation space and entry 20/03/

36 VIRGINIA HAND CALLAWAY DISCOVERY CENTER Circulation and Exhibit Spaces Outside Closed areas 20/03/

37 VIRGINIA HAND CALLAWAY DISCOVERY CENTER Lake Source Heat Exchangers for Annual Cycle Heat Pump storage 20/03/

38 CALLAWAY DISCOVERY CENTER CAVEATS Attachment of piping with staples to board insulation Post-pouring slab cuts and piping integrity Controls of radiant floor Sizing of lakeside heat exchangers Winter lake temperatures and minimum leaving chilled water temperature No floor condensation, good environmental control so far 20/03/

39 HEARST TOWER 20/03/

40 HEARST TOWER 20/03/

41 HEARST HEADQUARTERS Radiant Heating/Cooling Floor - Displacement Ventilation 20/03/

42 HEARST HEADQUARTERS Lobby Temperature Sections 20/03/

43 HEAST HEADQUARTERS Lobby Temperature Sections 20/03/

44 HEARST HEADQUARTERS Lobby Temperature Sections 20/03/

45 HEARST HEADQUARTERS Radiant Heating/Cooling Floor Geometry and CFD Results 20/03/

46 HEARST HEADQUARTERS Chilled Water Feature Radiant Floor Tubing 20/03/

47 DARTMOUTH COLLEGE McLaughlin Hall (2006) 20/03/

48 DARTMOUTH COLLEGE McLaughlin Hall (2006) Geometry Cooling Radiant Floor CFD Analysis Heating 20/03/

49 THE WILLIAM JEFFERSON CLINTON PRESIDENTAL CENTER LEED NC 2.1 Silver 20/03/

50 THE WILLIAM JEFFERSON CLINTON PRESIDENTIAL CENTER 20/03/

51 THE WILLIAM JEFFERSON CLINTON PRESIDENTIAL CENTER Computational Fluid Dynamics Studies of Museum Area - Temperature, Flow and Ventilative Effectiveness 20/03/

52 THE WILLIAM JEFFERSON CLINTON PRESIDENTIAL CENTER 20/03/

53 SYRCAUSE UNIVERSITY SCHOOL OF MANAGEMENT 20/03/

54 SYRACUSE UNIVERSITY SCHOOL OF MANAGEMENT Radiant Floor Tubing Radiant Floor Tubing 20/03/

55 GAYLORD NATIONAL HARBOR HOTEL 20/03/

56 GAYLORD NATIONAL HABOR HOTEL CFD Analyses for Cooling 20/03/

57 SAP AMERICAS HEADQUARTERS EXPANSION LEED NC 2.2 Platinum 20/03/

58 SAP AMERICAS HEADQUARTERS EXPANSION Thermally Active Lobby Floor 20/03/

59 SAP AMERICAS HEADQUARTERS EXPANSION Atrium Ground Coupled Thermally Active Slab System 20/03/

60 SAP AMERICAS HEADQUARTERS EXPANSION Thermally Active Slab in Construction 20/03/

61 PAVILION AT BROOKFIELD PLACE 20/03/

62 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 20/03/

63 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 20/03/

64 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 20/03/

65 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 20/03/

66 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 20/03/

67 RADIANT/HEATING COOLING GUIDELINES Measures to Avoid Condensation Supply generous amounts of dehumidified air for ventilation Keep chilled water supply temperature well above design interior dew-point temperature Design exterior wall to minimize infiltration Specially treat entrances and exits with dehumidified air Delete radiant piping from area immediately surrounding entrances Use chilled water for interior water features Shut down circulating pump upon detection of high interior dew point temperature 20/03/

68 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 20/03/

69 RADIANT/HEATING COOLING GUIDELINES Construction and Coordination Caveats Insure tops of manifolds are located higher than floor tubing to facilitate air elimination Monitor ferrous metal in radiant loop Verify that tubing has oxygen barrier If not, verify that pumps, heat exchanger, air eliminator, valves, strainers, etc. are all completely non-ferrous Non-ferrous air eliminators are limited in size Consider using two in parallel Beware ferrous nipples on expansion tanks Beware topping slab and finish substitutions Insure 120 lb./cf concrete to insure good heat transfer Monitor carpet or flooring submittals 20/03/

70 RADIANT/HEATING COOLING GUIDELINES Construction and Coordination Caveats Topping slab detailing under some floor finishes, especially terrazzo should be coordinated with the architect and structural engineers Glass fiber reinforcement in the topping slab is especially effective in limiting cracking Thermally active floors demonstrate markedly lower temperature variation than passive floors Active floors vary between 68 DegF and 80 DegF Passive floors can go over 100 DegF in bright sunlight and under 65 DegF on cold days Explicitly locate tubing on design documents Tie down tubing to make sure it stays where it is initially placed Use nylon wire tires to wire mesh or barbed staples into slab insulation Preferred sub-topping slab insulation is 100 psi polystyrene foam, available only in 2 depths 20/03/

71 RADIANT/HEATING COOLING GUIDELINES Construction and Coordination Caveats Plan for Partition construction and relocation if likely to occur Partition bottom channels will likely be secured to concrete slab with shot fasteners Fasteners can penetrate tubing imbedded in topping slab If partitions will not move, plan tubing routing to enter rooms through door rather than crossing walls If partitions may be moved or installed later, consider increasing depth of topping slab, or specifying short fasteners used in conjunction with mastic to secure bottom channel to slab Coordinate location of slab sensors and conduit connected to them with radiant tubing layout DO NOT CROSS EXPANSION JOINTS WITH PEX TUBING 20/03/

72 ACKNOWLEDGEMENTS St. Meinrad Archabbey Church William Jefferson Clinton Library Architect Woollen Molzan Partners, Indianapolis, IN Architect Polshek Partners., New York, NY Building Services Engineers Building Services Engineers Roger Preston + Partners, Atlanta Flack + Kurtz, NYC Virginia Hand Callaway Center Architect - Robert Lamb Hart, NYC Pier 1 Cromwell Architects, Engineers, Little Rock, AR Building Services Engineers Architect SMWM Architects, San Roger Preston + Partners, Atlanta and Francisco, CA Creative Engineering Design, Atlanta Building Services Engineers IBT Headquarters Flack + Kurtz, San Francisco, CA Architect Murphy Jahn, Chicago, IL Dartmouth College McLaughlin Residences Building Services Engineers Architect Bruner Cott, Boston, MA, and Flack + Kurtz, San Francisco, CA Moore, Ruble, Yudell, Architects, Santa Monica,CA Hearst Headquarters Building Services Engineers Flack + Kurtz, NYC Architect Foster and Partners, London, UK Gaylord National Harbor Hotel Building Services Engineers Architect - Gensler Flack + Kurtz, NYC Building Services Engineer WSP Flack + Kurtz, NYC Syracuse University School of Management SAP Corporate Headquarters Architect F X Fowle, NYC Architect F X Fowle, NYC Building Services Engineers - Flack + Kurtz, NYC Building Services Engineers - Flack + Kurtz, NYC 20/03/

73 References: Nall, D. H., Lessons Learned in the Design, Construction and Operation of Thermally Active Floors, Part 1: Design of the Systems, ASHRAE Journal, Atlanta, GA, January 2013 Nall, D. H., Lessons Learned in the Design, Construction and Operation of Thermally Active Floors, Part 2: Design of the Systems, ASHRAE Journal, Atlanta, GA, February Nall, D. H., Lessons Learned in the Design, Construction and Operation of Thermally Active Floors, Part 3: Making it Work, ASHRAE Journal, Atlanta, GA, March /03/

74 Daniel H. Nall, FAIA, PE, FASHRAE, LEED Fellow, HBDP, BEMP 20/03/