Getting to 50: 50% Advanced Energy Design Guide for Small and Medium Office Buildings. WSP Flack + Kurtz

Transcription

1 Getting to 50: 50% Advanced Energy Design Guide for Small and Medium Office Buildings Daniel H. Nall, FAIA, PE, LEED Fellow, BEMP, HBDP WSP Flack + Kurtz February 7, 2012 D D d d

2 AIA Learning Objectives Give a brief history of the ASHRAE Advanced Energy Design Guides Describe the development of the new 50% guides and compare it with that of the previous 30% AEDG series. Demonstrate how the requirements of the guide were developed using comprehensive energy modeling. Identify the energy conservation measures required and the issues addressed in the new guides. 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 ASHRAE Records for AIA members. Certificates of Completion for non-aia members are available on request. 2 This program is registered with the AIA/ASHRAE 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 Advanced Energy Design Guides Six 30% Guides Published and Available for Free Download Circulation of 30% series guides is over 300,900 copies as May 2011 The 30% AEDGs help promote building energy efficiency worldwide

4 Advanced Energy Design Guides Six 30% Guides published and available for free download Circulation of 30% Series Guides is 300,000+ copies 30% energy savings over Small Office Small Retail K-12 School The 30% AEDGs help promote building energy efficiency worldwide Free download at: Warehouse Highway Lodging Small Hospital

5 Advanced Energy Design Guides Three 50% Guides published and available for free download 50% Guide for Small and Medium Hospitals under development Free download at: Office Medium, Big Box Retail K12 Schools

6 Process for 50% AEDGs Conduct the TSD analysis first Then Convene the AEDG Project Committee Launched the 50% AEDG Small to Medium Office project committee on 7/30/2010 Circulated the Concept Draft for peer review on 9/2/2010 Published this first 50% AEDG guide on 5/2/2011

7 50% AEDG Project Context Provide prescriptive packages to help owners and designers achieve 50% site energy savings over ASHRAE Present climate specific recommendations by building types Not a code or standard PNNL published 50% TSDs on small and medium offices before the project committee was convened. Additional analysis conducted based on recommendations from the project committee 50% AEDG SMO was published in May,

8 AEDG Medium Office Building Project Committee 8 A group of industry professionals representing ASHRAE, AIA, USGBC, IES, and DOE Bing Liu, Chair Merle McBride, Vice-chair Daniel Nall, AIA/USGBC Representative Mick Schwedler, ASHRAE Representative Michael Lane, IES Representative Don Colliver, Steering Committee Ex Officio Mathew Tanteri, IES Representative Erin McConahey, Member at Large Lilas Pratt, Staff Liaison Brian Thornton, Analysis Support Weimin Wang, Analysis Support

9 AEDG Big Box Retail Project Committee A group of industry professionals representing ASHRAE, AIA, USGBC, IES, and DOE Shanti Pless, Chair Merle McBride, Vice-chair Daniel Nall, AIA/USGBC Representative Carol Marriott, ASHRAE Representative Michael Lane, IES Representative Don Colliver, Steering Committee Ex Officio Bernie Bauer, IES Representative Scott Williams, AIA/USGBC Representative Lilas Pratt, Staff Liaison Eric Bonnema, Analysis Support Matt Leach, Analysis Support 9

10 AEDG Technical Support Documents Process and methodology for the development of the guides Detailed energy saving analysis assumptions and results Development of the recommendation criteria Cost-effectiveness analysis (warehouse, school, and hotel)

11 50% Advanced Energy Design Guides 50% Advanced Energy Design Guide includes: Prescriptive Recommendations Tables How to Implement Tips Plus more: Expanded Guidance on Integrated Design Performance Strategies for those not using the Prescriptive Recommendations General Strategies by Climate Zone

12 Prototype Building- Small Office 20,000 ft 2, 100 ft by 100 ft 2 floors, 12 ft floor-to-floor height Concrete block construction 20% window-to-wall ratio Two alternative constant air volume systems Packaged air conditioner with DX for cooling and gas furnace for heating Packaged air source heat pump with electric supplemental heating 12

13 Prototype Building- Medium Office 53,600 ft 2, 164 ft by 109 ft 3 floors, 13 ft floor-to-floor height Steel frame construction 33% window-to-wall ratio Variable air volume system with DX for cooling Heating Electric reheat for climate zones 1 through 4 Hot water baseboard heating for climate zones 5 through 8 13

14 Baseline Energy Usage (Baltimore) Heating 32% SWH 2% Interior Lighting 19% Heating 24% SWH 2% Interior Lighting 19% Exterior Lighting 10% Exterior Lighting 10% Cooling 7% Fans 10% Plug Loads 20% Small Office Site EUI = 57.7 kbtu/sf/year Cooling 14% Fans 7% Plug Loads 24% Medium Office Site EUI = 58.7 kbtu/sf/year 14

15 Medium Office Radiant with DOAS SWH Heating Cooling Heat Recovery Aux. Pumps Fans Equipment Exterior Lights Interior Lights National weighted average of EUI saving: 52.8% Site EUI (kbtu/sf/year) % 54% 55% 52% 53% 51% 54% 55% 52% 55% 51% 50% 51% 51% 54% 53% Climate Location

16 AEDG Document Content Chapter Introduction How to use this document Chapter 2 Integrated Design Process How the design process changes in order to achieve 50% energy savings Chapter 3 Integrated Design Strategies Overview of the technical approaches to achieving 50% savings Chapter 4 Design Strategies and Recommendations by Climate Zone Specific technical requirements to meet the 50% goal Chapter 5 How To Implement Recommendations Specific technical guidance for implementation of recommendations, including technical resources and warnings Appendices Envelope Thermal Performance Factors International Climatic Zone Definitions Commissioning Information and Examples Early Phase Energy Balancing Calculations

17 AEDG Recommendations Format

18 Building Envelope

19 Building Envelope Strategies 1 - Upgrade the Envelope Thermal Efficiency 2 Make Fundamental Changes to the Building Basic Structure and Form 3 Incorporate New Features

20 1 - Upgrading Envelope Thermal Efficiency Roofs Walls Floors Slabs Doors Vestibules Fenestration Daylighting

21 Horizontal Slab Thermal Performance R-value Climate Zone - No Thermal Bridges - Stagger edges of multiple layers Insulation Above Deck SMO F-factor Unheated Slabs Climate Zone SMO

22 Wall Thermal Performance R-value R-value Climate Zone SMO Climate Zone Mass Walls Steel Framed Walls SMO

23 Vertical Fenestration U-factor SMO U-factor Climate Zone SHGC 0.4 SHGC SMO Climate Zone

24 Alternative Opaque Constructions

25 2 Building Structure and Form Vestibules Building Orientation and Daylighting Building Shape and Daylight Windows Daylighting Glass Exterior Sun Control Correct Lighting Levels

26 Vestibules Primary Occupant Entrances (Excluded: Emergency Exits, Maintenance Doors, Loading Docks and Specialty Entrances) CZ 1-2 = No recommendation CZ 3 = Buildings > 10,000 ft 2 CZ 4-8 = All Offices

27 Building Shape and Daylight Locate occupied spaces within a minimum distance from the perimeter. Shape building footprint so all occupants are within 30 ft of perimeter fenestration Shape building footprint so regularly occupied spaces are within 15 ft of the perimeter. Ensure that 75% of the occupied spaces are within 20 ft of the perimeter wall. In clear sky conditions illuminance levels should be 25 fc to 250 fc. In overcast conditions achieve a daylight factor of 2% but no more than 20%.

28 Building Orientation and Daylighting Vertical facades that provide daylighting should be oriented within 15 o of north and south directions. Orientation: A w and A e each < A s Window-to-Wall Ratios: 20% to 40%

29 Windows Window Performance - VT = 0.6 to Minimum VT/SHGC =1.10 in all CZ - Vertical Fenestration EA = 0.12 in all CZ

30 Exterior Sun Control (South, East and West) PF = 0.5

31 3 New Features Mitigation of Thermal Bridges Continuous Air Barriers Thermal Mass to Reduce Loads

32 Mitigation of Thermal Bridges Roofs Windows Foundations

33 Continuous Air Barriers Entire Building Envelope for all Offices in All Climate Zones

34 Thermal Mass Reduce Thermal Loads Improve Thermal Comfort Passive Solar Designs (Lobbies, Corridors, Etc.)

35 Lighting and Daylighting

36 Daylighting Recommendations Use a shallow floor plate Locate workstations next to North or South windows Use low partitions with translucent materials Locate private offices on east and west perimeters Use light-colored matte finishes For controls daylight dimming in open offices occupancy sensing in private offices and conference rooms w/ daylight override

37 Electric Lighting Recommendations Reduce Lighting Power Densities

38 Electric Lighting Recommendations Reduce Lighting Power Densities High Performance lensed fluorescent fixtures 90+ lpw fluorescent lamps NEMA Premium ballasts Dim general lighting in Open Offices Use dual circuit occupancy sensors in Private Offices Night lighting (10% max)

39 Electric Lighting Recommendations Exterior Lighting calculate LPD only for areas intended to be lighted. areas that are lighted to less than 0.1 fc are assumed to not be lighted design with a maximum to minimum ratio of illuminance no greater than 30 to 1 (if the minimum light level is 0.1, then the maximum level in that area should be no greater than 3 fc) reduce power between 12:00 p.m. and 6:00 a.m. to no more than 50% turn façade lighting OFF after midnight use lighting zone 3 or lower recommendations

40 Climate Zone Recommendations

41 Integrated Design

42 Integrated Design Approach AEDG presents: A Way Not The Only Way through the prescriptive tables. A tutorial on the elements of Integrated Design for Energy Conservation. A description of required design tasks for energy conservation by design phase. The importance of energy modeling for design of building not amenable to tables.

43 Entire Building Configuration Determines Energy Performance

44 Savings Opportunities Vary with Climate

45 Cumulative Impact of Integrated Approach

46 HVAC Systems

47 Grounds Rules for Prescriptive Path Products must be available from at least 2 manufacturers Systems must be within first cost range of conventional systems Savings are determined based on modeling with ASHRAE as the Base Case. All systems and products must be compliant with ASHRAE Systems must provide compliance with ASHRAE and ASHRAE

48 Principles for HVAC Efficiency High full load efficiency and maximized part load efficiency (units rarely operate at full load) Humidity control and ventilation maintenance without reheat - Vary airflow for load modulation with constant maximum apparatus dew point - Separate ventilation airflow from sensible conditioning and maintain constant maximum apparatus dewpoint in ventilation airflow Move only as much air as necessary - Vary airflow with sensible load - Disable conditioning air flow when possible Independent controls for ventilation and sensible cooling Heat or energy recovery in almost all climate zones

49 System types for 50% savings Constant volume air-source heat pumps with DOAS Water source heat pumps with DOAS VAV Fan coils with DOAS Radiant heating/cooling with DOAS Air-cooled VAV DX units with indirect gas-fired heat or with electric baseboards Chilled water VAV with air-cooled chiller and with hydronic distribution and condensing boiler or electric baseboards Others may work, but weren t tested for this study

50 30% AEDG solutions that don t work for 50% savings Constant volume systems without Dedicated Outdoor Air System (DOAS) Constant Volume DX cooling only systems even with DOAS Constant outdoor air ventilation

51 Air Source Heat Pump With DOAS Premium DX heating/cooling efficiency Very low exterior temperature heating performance (-4 F) DOAS with energy recovery and humidity control Unit fan and compressors cycle with load Low pressure drop ductwork design Demand controlled ventilation (DCV) Motorized damper control Ventilation Airflow monitoring per

52 Air Source Heat Pump System Results

53 Advanced VAV System Premium DX cooling efficiency Energy recovery ventilator All except 3B-CA, 3B other, 3C Supply air temperature reset Previously excluded 3A and 4A Indirect evaporative cooling 2B, 3B-CA, 3B other, 4B, 5B Demand controlled ventilation (DCV) Motorized damper control Ventilation Airflow monitoring per

54 Advanced VAV System Results

55 Water Source Heat Pump with DOAS Heat pump units -in 5 ton size range - Single stage, EER 16.4, COP Two-stage part load/full load EER 17.6/15.0, -COP 5.7/5.0 - ECM fan motors Loop heating and cooling - Cooling tower, variable speed or two speed fan - Condensing boiler - Optimize loop cooling temperature DOAS with energy recovery and humidity control

56 Water Source Heat Pump System with DOAS

57 Advanced Fan Coil System with DOAS Fan Coil Systems chilled and hot water coils - ECM fan motors - Fan coils cycle when no space loads Variable flow pumping DOAS with energy recovery and humidity control Chilled water supply - Efficient air-cooled chiller as described for VAV - 42 F for DOAS - Variable flow with pressure reset Hot water - Condensing boiler 140 F supply, 120 F return

58 Advanced Fan Coil Results

59 Advanced Radiant System with DOAS Radiant cooling/heating ceiling panels or floor Variable flow pumping DOAS with energy recovery and humidity control Chilled water supply - Efficient air-cooled chiller as described for VAV - 42 F for DOAS - 58 F for radiant system - Variable flow with pressure reset Hot water - Condensing boiler 120 F supply, 100 F return

60 Advanced Radiant System Results

61 Other HVAC Information in the AEDG How-To Tips Cautions References and Resources Detailed Discussion of Quality Assurance and Commissioning

62 Thank You Questions? Daniel H. Nall, FAIA, PE, LEED Fellow, BEMP, HBDP

63 xx 63

64 Roof Parapet

65 Windows

66 Foundations

67 Daylighting Glass - VT = 0.6 to Minimum VT/SHGC =1.10 in all CZ - Vertical Fenestration EA = 0.12 in all CZ

68 Correct Lighting Levels - In clear sky conditions illuminance levels should be 25 fc to 250 fc. - In overcast conditions achieve a daylight factor of 2% but no more than 20%.

69 Correct Lighting Levels - In clear sky conditions illuminance levels should be 25 fc to 250 fc. - In overcast conditions achieve a daylight factor of 2% but no more than 20%.