Advanced Energy Design and Retrofit Guides

Transcription

1 Advanced Energy Design and Retrofit Guides Paul A. Torcellini, Ph.D., P.E. Principal Engineer July 16, 2014 NREL is a national laboratory of the U.S. Department of Energy, Office of Energy Efficiency and Renewable Energy, operated by the Alliance for Sustainable Energy, LLC.

2 Why Buildings Energy Use is Important Largest energy consumer in U.S. 40% of U.S. Primary Energy Consumption 72% of U.S. Electricity 55% of U.S. Natural Gas 2

3 Trend of Commercial Sector Commercial Sector Energy Use is growing at 1.6% per year Growth is faster than energy efficiency measures Need to think about Zero-Energy Buildings to change overall trends Every decision has an energy impact Buildings mortgage the energy futures of this country 1.60 Indices of Commercial Energy Use, Activity, Weather, and Intensity, (and the world) , (1985 =1.00) Energy Consumption Floorspace Intensity Index (weather -adjusted) Weather Factor Source: DOE/EERE Website, "U.S. Energy Intensity Indicators"

4 Many Pieces So many ways to assemble the pieces Design is about making decisions need motivation to make the right decisions Who are the decision makers? Used by permission: Paul Torcellini/NREL 4

5 Great Potential in Commercial Buildings Clockwise from top: NREL/09202, 10884, 10140, 09249, 12637,

6 Setting Goals Measurable goals are better From bad to good I want a green building Design a LEED <rating> building Design a building to use 30% less energy than ASHRAE Design a building to use less than 25,000 BTU/sqft Design a [NET] ZERO ENERGY BUILDING Influencing purchasing decision the owner 6

7 Real Value Added II I Value Added III IV 7

8 Opportunities in Building Life Cycle for whole building retrofits Remodeling or market repositioning Roof, window, or skin replacement (may be cosmetic) End (or near end) of life HVAC, lighting, or other major equipment replacement Upgrades to meet code (not necessarily energy) New owner or refinancing Major occupancy change Building greening Large utility incentives Fixing an energy hog 8

9 Advanced Energy Retrofit Guides 9

10 Purpose Provide energy managers with comprehensive guidance for planning and executing successful retrofit projects in commercial buildings, tailored to specific building types and climate regions 10

11 Emphasis on How-To Guidance How to: Benchmark energy use. Select the most appropriate financing mechanism and audit method. Save energy immediately by commissioning existing buildings. Identify the best energy efficiency measures to consider for a given retrofit project. Determine whether a building is a good candidate for a wholebuilding retrofit. Apply integrated design principles. Improve O&M procedures to keep equipment operating as intended. Apply standard M&V protocols to ensure expected energy savings persist over time. 11

12 AERG Audiences 12 12

13 Categories of Retrofit Three categories of efficiency improvement Existing building commissioning (EBCx) Low-cost/no-cost measures Quick payback Staged retrofit Multiphase series of improvements Timed with planned equipment replacements Whole-building retrofit Higher savings possible Timed with building remodeling, repurposing, or other major building change 13

14 Typical Grocery Store Retrofit Process 14 14

15 Recommended Retrofit Package Results 15

16 The AEDG Series How do I achieve these energy savings targets (i.e., 30% or 50%) in new construction? Guidance and recommendations by building type and geographic location Collection of experts and combined experience Apply to new commercial construction Educational guidance not a code or standard Two AEDG series: 30% energy savings 50% energy savings 16

17 Advanced Energy Design Guides Six 30% Guides published and available for free download Circulation of 30% Series Guides is 400,000+ copies 30% energy savings over Small Office Small Retail K-12 School The 30% AEDGs help promote building energy efficiency worldwide Warehouse Highway Lodging Small Hospital 17

18 Advanced Energy Design Guides Four 50% Guides published and available for free download Circulation of 50% Series Guides is 100,000+ copies 50% energy savings over Office Medium, Big Box Retail Hospitals K12 Schools 18

19 Evaluation Approach 19

20 AEDG Table of Contents 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 20

21 Guide Contents Case Studies Richardsville Elementary School Bowling Green, Kentucky 74,500 ft 2, 2-story, 500 students R-30 white roof R-28.6 insulation concrete form walls Daylighting with light shelf and tubular daylighting devices LPD of 0.68 W/ft 2 Dual compressor water-to-water heat pump Dedicated outdoor air system (DOAS) Ground heat exchanger Demand controlled ventilation Exclusive use of laptop computers All electric high-performance kitchen Submetered HVAC, DOAS, lighting, kitchen, information technology, and plug loads 17 kbtu/ft 2 yr whole-building energy use intensity 21

22 Guide Contents Technology Case Studies Daylighting Examples Variable-Speed Compressors 22

23 AEDG Recommendations Format 23

24 Mitigation of Thermal Bridges Roofs Windows Foundations 24

25 Plug Loads How-To Tips Use Energy Star equipment Enable Sleep Mode in all applicable equipment Occupancy sensor controlled outlets Time clock or switch control of outlets for parasitic loads (rechargers) Use equipment tested to ASTM efficiency standards Use commercial kitchen equipment that minimizes hot water usage. Use commercial refrigeration equipment compliant with EPCA 2007 Amendments Use regenerative traction elevators for high usage applications 25

26 5. Service Water Heating How-To Tips Use Energy Star water heaters Utilize automatic aerator faucets to minimize hot water usage Utilize point-of-use instantaneous water heaters for widely distributed fixtures. Locate heaters as close as possible to load to minimize piping losses. Consider heat pump tank-type water heaters in warm climate zones Explore opportunities for DHW pre-heat using heat recovery from refrigeration. Use commercial refrigeration equipment compliant with EPCA 2007 Amendments Use solar thermal 26

27 RSF uses 50% less energy than if it were built to current commercial codes RSF increases space at NREL by 60% but only increases energy use by 6% NREL/

28 Day vs. Night Plug and Process Loads Only occupied about ⅓ of the time -Nights Unoccupied -Weekends Unoccupied -Holidays Unoccupied Occupied Hours Power Density (W/ft 2 ) Annual Plug Load Energy Use Intensity (kbtu/ft 2 ) Unoccupied Hours Power Density (W/ft 2 )

29 RSF Plug Load Reduction Strategies Elevators Use energy efficient traction elevators Change elevator lighting to energy efficient fluorescent lighting Turn off elevator lighting when the elevator is unoccupied Break Rooms Increase the number of people that use each break room from approximately 40 to 60 Eliminate the cooler on the drinking fountain Task Lights Move from 35W fluorescent task lights to 6W LED task lights Phones Go from 1000 standard phones to 1000 VOIP phone that consumes 2W each Copiers, Printers, Fax Machines Decrease the number people that use individual copiers, printers and fax machines Increase the number of people that use common, or group, copiers, printers and fax machines from 15 to 20 Increase the use of all-in-one machines Computers Go from approximately 260 laptops, 33% of staff, to 720, 90% of staff, ensure standby mode works for all workstations Data Center Blade Servers with Virtualization High efficiency UPS 65W/employee current to 48W/employee in RSF The result of these strategies is a 47% reduction in plug loads EUI (kbtu/ft 2 ) Baseline vs RSF Plug Load EUI Baseline RSF Coffee Kiosk Elevator Lighting Elevators Drinking Fountains Vending Machines Microwaves Coffee Pots Refrigerators Task Lights Phones Fax Machines Copiers Printers Computers Data Center Conference Room Equipment Telecom Room Equipment Misc 29

30 Final Thoughts Set high goals 50% or more energy savings is possible to achieve. Let us know your experiences and needs Submit your case studies and stories Buildingdata.energy.gov 30

31 More Information buildingdata.energy.gov/cbrd (commercial buildings resource database) Search on aedg or aerg openstudio.nrel.gov commercialbuildings.energy.gov 31

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