Energy Management in Existing Buildings

Transcription

1 Energy Management in Existing Buildings Davor Novosel Chief Technology Officer National Energy Management Institute Committee

2 Overview Why manage energy? Why existing buildings? How big is energy savings opportunity? Meeting energy goals New paradigm: energy performance in context of human performance Start with TAB to meet energy goals Impact of TAB accuracy on your budget 2

3 Why Manage Energy? 3

4 Why Manage Energy?.1 Energy is in the news daily Consumer experiences with volatile fuel costs Focus of public policy Focus of conservation movement 4

5 Why Manage Energy?.2 How We Use Energy Transportation 28% 19% Commercial Buildings 22% 31% Industrial Residential Buildings 5

6 Why Manage Energy? Survey of U.S. Commercial Buildings Stock (CBECS) ,000 1,200 Education Food Sales Food Service Healthcare Inpatient Healthcare Outpatient Lodging Retail (Other Than Mall) Office Heating Cooling Ventilation Water Heating Lighting Cooking Refrigeration Office Equipment Computers Other Public Assembly Public Order and Safety Religious Worship Service Warehouse and Storage Other Major Fuel Consumption (trillion Btu) by End Use for Non-Mall Buildings 6

7 Why Manage Energy?.4 Energy Targets Federal government: Executive Order Energy Independence and Security Act of 2007 (EISA) EnergyStar State Energy Program (SEP) State and local governments Private incentives: LEED, Green Globes, etc. 7

8 Owner Perspective Energy Cost.. $2.50/ft² Rent... $35.00/ft² Why Manage Energy?.5 Energy cost about 8 to 12% of net lease Tenant Perspective Energy Cost.. $2.50/ft² Employee Cost.. $250.00/ft² Energy cost less than 1% of operating budget Improve Energy Efficiency = Reduce Cost by 30% Operating profit increases by 33%! Impact on operating budget lost in rounding error 8

9 Why Existing Buildings? 9

10 Why Existing Buildings?.1 Rate of Change of Buildings Our basic argument is that there is no such thing as a building. A building properly conceived is several layers of longevity of built components. Francis Duffy, DEGW 10

11 Why Existing Buildings?.2 Shearing Layers of Change (Stewart Brand: 6 S ) Space Plan: 5-7 years Services: years Skin: years Structure: years Site: eternal 11

12 Capital Cost Why Existing Buildings?.3 Building Life Cycle Costs Traditional View of Building Costs Cumulative Total over 50 Years Space Plan Space Plan: 5-7 years Services: years Structure: 50 years Services Structure Building Age 12

13 Why Existing Buildings? Survey of U.S. Commercial Buildings Stock (CBECS): 4,859,000 buildings billion ft² Median building size ~ 5,000 ft² Median age = 50 yrs

14 Why Existing Buildings?.5 because in 50 years most of the buildings constructed today will still be standing. Net-zero energy goals will have no broad impact until significant building stock has been replaced. Existing buildings offer the largest energy savings potential 14

15 Meeting Energy Goals 15

16 Meeting Energy Goals.1 Issues Measure of large scale energy improvements are not clearly defined Means how to measure are unclear Quantifying energy use of a building is difficult because Utility bills only provide consumption but not actual building energy efficiency Energy consumption is influenced by uncontrollable parameters (occupancy, usage patterns, type, weather) that may vary widely from year to year No general agreement on how to assess building performance Easy to use, comprehensive building performance metrics are absent 16

17 Meeting Energy Goals.2 Currently accepted measure of the energy performance of a building: Energy Utilization Index (EUI) EUI = Annual Energy Consumption Gross Square Footage 17

18 Meeting Energy Goals.3 Building energy performance normative data: Commercial Buildings Energy Consumption Survey (CBECS) EnergyStar Portfolio Manager 18

19 ASHRAE Std Energy Consumption, kbtu/f²-yr ASHRAE Std 90A-1980 ASHRAE Std ASHRAE Std ASHRAE Std ASHRAE Std ASHRAE Std ASHRAE Std Meeting Energy Goals.4 DOE/EIA CBECS Trend with 95% CI (June 2006) Average = 88 kbtu/f²-yr Year 19

20 ASHRAE Std Energy Consumption, kbtu/f²-yr ASHRAE Std 90A-1980 ASHRAE Std ASHRAE Std ASHRAE Std ASHRAE Std ASHRAE Std ASHRAE Std Meeting Energy Goals.5 DOE/EIA CBECS Trend with 95% CI (June 2006) Average = 88 kbtu/f²-yr 75 EO (PBS P100) AIA BEPS (1976) EO EO Year 20

21 ASHRAE Std Energy Consumption, kbtu/f²-yr ASHRAE Std 90A-1980 ASHRAE Std ASHRAE Std ASHRAE Std ASHRAE Std ASHRAE Std ASHRAE Std Meeting Energy Goals.5 DOE/EIA CBECS Trend with 95% CI (June 2006) 125 Federal Facilities (2012) = 101 kbtu/f²-yr AIA BEPS (1976) EO Typical GSA Target : 16kBtu/ft²-yr Year 21

22 A New Paradigm 22

23 A New Paradigm.1 A building should be: Healthy Comfortable Energy Efficient Material Efficient Easy to Maintain and Operate Commissioned On an Environmentally Responsive Site A Building That Teaches Safe and Secure Community Resource Stimulating Architecture Adaptable to Changing Needs CHPS Definition of a high performance school 23

24 A New Paradigm.2 A building should be Occupant Centric Healthy Comfortable Safe and Secure A Building That Teaches Community Resource Space Centric Energy Efficient Easy to Maintain and Operate Adaptable to Changing Needs (Continuously) Commissioned Structure Centric Environmentally Responsive Material Efficient Stimulating Architecture 24

25 A New Paradigm.3 Purpose of a Building Provide secure, safe, and healthy conditions Facilitate well being and productivity of occupants METRICS Human Response Occupant Performance Productivity Achieve by simultaneous control of exposure parameters Thermal IAQ Lighting Acoustics 25

26 A New Paradigm.4 26

27 EUI/month A New Paradigm.5 Total EUI 49,919 Btu/ft 2 year 189,000 gross ft² (?) 50% Reduction vs. ASHRAE (LEED objective) 6,000 5,000 4,000 3,000 Total Steam & Electricity Electricity 2,000 1,000 Steam - Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Jan

28 A New Paradigm.6 LEED Score Card 8 Points for 50% better than ASHRAE

29 A New Paradigm.7 Summary of occupant responses to their perception for acceptability of IEQ Building Meets Performance Intent Temperature Humidity Draft VOCs Sound Lighting Never Occasionally Some of the time Most of the time All of the time 29

30 A New Paradigm.8 70% 60% 50% 40% 30% 20% 10% Over the past 4 weeks, I would rate the overall comfort of my work area as acceptable 0% Never Occasionally Some of the time Most of the time All of the time 30

31 A New Paradigm.9 Overall Acceptability (OA) Most of the Time = 63.27% All of the Time = 8.16% Building Occupant OA = 71.43% 31

32 A New Paradigm.10 Nominal Office Buildings Occupant OA EUI 100% 500,000 Occupant OA 100% High Performance Office Buildings EUI 500,000 90% 450,000 90% 450,000 80% 400,000 80% 400,000 70% 350,000 70% 350,000 60% 300,000 60% 300,000 50% 250,000 50% 250,000 40% 200,000 40% 200,000 30% 150,000 30% 150,000 20% 100,000 20% 100,000 10% 50,000 0% % 50,000 0%

33 A New Paradigm.11 Q: Is there a relationship between occupants overall acceptance of the IEQ and energy performance (EUI)? A: A very tentative Yes! A new Figure of Merit (FOM) = EUI / %OOA 33

34 2,000 1,800 1,600 1,400 1,200 1, A New Paradigm.12 EUI/%OAA [Btu/ft²-yr/%OOA] Nominal Building HP Building Mean +/- SD for Buildings w/o outlier and zeros Nominal Buildings = /- 540 Btu/ft²-yr/%OOA HP Buildings = 878 +/- 332 Btu/ft²-yr/%OOA ID of Nominal and HP Building 34

35 Start with Testing, Adjusting and Balancing (TAB) to Meet Energy Goals 35

36 Start with TAB to Meet Energy Goals.1 36

37 Start with TAB to Meet Energy Goals.2 Many pieces of equipment that need to operate in unison No design is the same Usage changes over time Equipment degradation over time Control system degradation 37

38 Start with TAB to Meet Energy Goals.3 When to do TAB? Commissioning? Start-up? Tenant change? Annually? Change-over? When budget allows? 38

39 Capital Cost Start with TAB to Meet Energy Goals.4 Building Life Cycle Costs Traditional View of Building Costs Cumulative Total over 50 Years Space Plan Space Plan: 5-7 years Services: years Structure: 50 years Services Structure Building Age 39

40 Start with TAB to Meet Energy Goals.5 Staged Approach to Building Upgrades TAB Re-commissioning TAB Lighting Upgrades TAB Supplemental Load Reductions Air Distribution Upgrades TAB TAB HVAC Upgrades Base Load New Base Load 40

41 Start with TAB to Meet Energy Goals.6 Why do TAB? How often? By whom? Independent TAB contractor Mechanical contractor Commissioning contractor Who has the least conflict of interest and can act as your representative?! 41

42 Impact of TAB Accuracy on Your Budget 42

43 Impact of TAB Accuracy on Your Budget.1 Q: What is the sum of 2 + 2? - or How much tolerance is needed? An accountant will say "What do you want the answer to be?" A mathematician will say "I believe it is 4, but I will have to prove it." An economist will say "Based on today's thinking, the answer is 4 but the answer may be different tomorrow". An engineer will say "The answer is 4, but adding a safety factor we will call it 5". 43

44 Impact of TAB Accuracy on Your Budget.2 How precisely can you measure air flow? Popular flow hood: Accuracy = ±3% of full scale + 5 cfm 44

45 Instrument Tolerance Range Impact of TAB Accuracy on Your Budget.3 How precisely can you measure air flow? 10% 8% 6% 4% 2% 0% -2% % -6% -8% Airflow Rate (cfm) 45

46 Impact of TAB Accuracy on Your Budget.4 Q: As a FM should I care about TAB measurement accuracy? A: How much operating $$ do you want to waste? Fan equation: bhp new bhp old = [ cfm new cfm old ]³ d new d old bhp actual = [ cfm actual cfm design ]³ bhp design TAB accuracy 46

47 Impact of TAB Accuracy on Your Budget.4 This is how much you are paying bhp actual = [ cfm actual cfm design ]³ bhp design This is how much you should be paying 47

48 bhp Ratio Impact of TAB Accuracy on Your Budget TAB accuracy under good conditions Percentage Difference Actual to Design Airflow Rate 48

49 Impact of TAB Accuracy on Your Budget.6 Add l Annual Operating Cost per bhp (10 /kwh, eff motor =0.94) $100 $80 TAB accuracy under good conditions $60 $40 $ EFLH 1000 EFLH 500 EFLH $ Percentage Difference Actual to Design Airflow Rate 49

50 How to Specify TAB? Masterformat 2004 Division 23 - Heating, Ventilating, and Air-Conditioning (HVAC) Section : Testing, Adjusting, and Balancing for HVAC; last updated May 2010 Section : Commissioning of HVAC Defines scope, objectives, procedures, Contractor's responsibilities. 50

51 Summary Why manage energy? Why existing buildings? How big is energy savings opportunity? Meeting energy goals New paradigm: energy performance in context of human performance Start with TAB to meet energy goals Impact of TAB accuracy on your budget 51

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53 Contact Information Davor Novosel Chief Technology Officer National Energy Management Institute Committee 8403 Arlington Boulevard, Suite 100 Fairfax, VA