An O&M Formula for Improved Life Cycle Cost

Transcription

1 An O&M Formula for Improved Life Cycle Cost Leveraging Best Practices and Low Cost/No Cost Solutions to Improve Efficiency and Support Sustainable Operations Presented By: David Sellers, Senior Engineer Facility Dynamics Engineering

2 A Formula for Improved Life Cycle Cost Given : ( Operations + MaintenancePreventive) Operator = Life Cycle CostBest Optimized Knowledge 2

3 A Formula for Improved Life Cycle Cost Given : ( Operations + MaintenancePreventive) Operator = Life Cycle CostBest Optimized and Knowledge ( Operations + MaintenancePreventive) = O & MBest Practices Optimized 3

4 A Formula for Improved Life Cycle Cost Given : ( Operations + MaintenancePreventive) Operator = Life Cycle CostBest Optimized and ( Operations + Maintenance ) Optimized Preventive Knowledge = O & M Best Practices Substituting : O & M Best Practices Operator Knowledge = Life Cycle Cost Best 4

5 A Optimized Formula Operations for Improved Life Cycle Cost Given : ( Optimized ( Operations + MaintenancePreventive) Operator = Life Cycle CostBest and ( Operations + Maintenance ) Optimized Preventive Knowledge = O & M Best Practices Substituting : O & M Best Practices Operator Knowledge = Life Cycle Cost Best 5

6 Optimized Set Points = Optimized Savings Cooling towers working hard to make 72 F water Theory; Lower condensing temperature = Lower chiller kw/ton Incrementally raising the set point to 80 F: Raised the chiller kw by 14 Dropped out two 20 hp (39kW total) continuously running tower fans Reduced consumption by $18,000 - $20,000 annually Based on $.07/kWh electricity 6

7 Optimized Application = Optimized Costs Shutting down one of two identical pumps piped in parallel provides more than 50% of the two pump flow rate Increasing Pressu ure Increasing Flow 50% Flow 100% Flow 7

8 Saving Energy with Sandbags South upper pool South upper middle pool South lower middle pool Sandbag (typical) Main water fall pool North middle pool North upper pool (verify which pump serves which pool) Lower collection pool Make-up (verify) Dr Dr Waterfall Pump 2 (2nd in from the door) 1,000 gpm (nominal) Dr Intake screen (typical) Cross-over valve throttled approximately 50% (look for the mark on the locking quadrant) Dr Dr Waterfall Pump 1 (closest to the door) 1,000 gpm (nominal) Dr Parallel pumps distribute water to two pools, one on each side of the central waterfall Water cascades through intermediate pools to a central pool Intermediate pools feed smaller waterfalls 8

9 Saving Energy with Sandbags Shutting down one pump: Generally, very little difference in sound or appearance Flow lost over one intermediate fall Minor elevation difference in the weir controlling flow out of the pool to on the North side vs. the South side 9

10 Saving Energy with Sandbags Using sandbags to modify the wiers between pools allows one pump to be shut down Annual savings 78,079 kwh; $9,838 Implementation cost - $13,915 including the new control system, scoping, investigation and program follow-up documentation and training 10

11 Control Installation By Staff = Understanding and Persistence 11

12 Optimized Operation on a Large Scale 800,000 square foot office building complex PGE program Buildings 2 to 19 years old Office space and computer labs Two central chiller/boiler plants 34 major air handling units 12

13 The Clues: High Baseline Consumption Average Daily Electrical Consumption 120, ,000 kwh 80,000 60,000 A significant portion of the baseline consumption could not be easily accounted for 40,000 20,000 0 J F M A M J J A S O N D Month 1997 Average Daily kwh Projected Lighting Load Contribution Projected Lighting Plus Equipment Plus Computer Room Load Contribution Projected Lighting Plus Equipment Load Contribution 13

14 The Clues: Boilers Firing on a 30-50% Duty Cycle In July to Serve Office Loads 14

15 The Discoveries Lots of chairs and conference rooms Chair count = 3 4 times the actual census Ventilation rate = 3-4 times the actual requirement Less than optimum control sequence 34 major air handling systems ran round the clock Served 500+ zones Most zones served 7am 5pm occupancies Isolated zones served 24 hour requirements 15

16 The Solutions Tailor the ventilation rates to the actual census Lower minimum flow rates Add occupancy sensors Optimize terminal unit sequences Implement zone level schedules Shut down flow to zones when unoccupied Allow conditions to drift between limits Reactivate flow prior to occupancy 16

17 Evidence of Success Terminal unit dampers forced to 0 cfm for unoccupied zones Flow immediately drops vs. drifting to minimum flow over time AHU3A Supply And Return Flow Evening Flow pattern prior to zone level scheduling Flow in Kcfm Weekend 0.00 Unoccupied flow rates are achieved immediately 12:00 AM 12:00 PM 12:00 AM 12:00 PM 12:00 AM 12:00 PM 12:00 AM 12:00 PM 12:00 AM 12:00 PM and are significantly Time lower in magnitude, saving JF3 AHU3A Supply Flow JF3 AHU3A Return Flow fan and reheat energy 17

18 Evidence of Success and something else to optimize AHU3A Supply And Return Flow Changing the system uncovered a new problem. The return flow now exceeds the supply flow during unoccupied hours! Flow in Kcfm :00 AM 12:00 PM 12:00 AM 12:00 PM 12:00 AM 12:00 PM 12:00 AM 12:00 PM 12:00 AM 12:00 PM Time JF3 AHU3A Supply Flow JF3 AHU3A Return Flow 18

19 The Results (2000 Energy Costs) Annual Savings - $130, % reduction of energy bill Electric, gas, and filter savings Implementation Costs - $124,200 Filters Programming Retro-commissioning service provider Simple Payback years 19

20 Digging Deep Can Save More than Energy RTU2 Temperatures - 1 Minute Sample Rate - December 7, Temperature e, F Temperature = 70 F Set point = 70 F 20 Everything s fine, right? 0 12 AM 1 AM 2 AM 3 AM 4 AM 5 AM 6 AM 7 AM 8 AM 9 AM 10 AM 11 AM 12 PM Date and Time Zone Average Temperature 20

21 Digging Deep Can Save More than Energy RTU2 Temperatures - 1 Minute Sample Rate - December 7, 2001 Temperature, F AM 1 AM 2 AM 3 AM 4 AM 5 AM 6 AM 7 AM 8 AM 9 AM 10 AM 11 AM 12 PM Date and Time Zone Average Temperature Discharge Airtemp Mixed Air Temp Outputs, % Outside Airtemp Heating Valve Position 21

22 More Than Energy is Being Wasted! 10 Cycles per hour translates to 87,600 cycles per year Actuator design life = 60,000 cycles Actuator cost = $300 - $500 Diagnosis/installation labor = 1-2 man hours at $75 - $100 per hour the operating charter for most Facilities Engineering groups does not include life cycle testing 22

23 A Preventive Formula for Maintenance Improved Life Cycle Cost Given : ( Operations + MaintenancePreventive) Operator = Life Cycle CostBest Optimized Maintenance Preventive and ( Operations + Maintenance ) Optimized Preventive Knowledge = O & M Best Practices Substituting : O & M Best Practices Operator Knowledge = Life Cycle Cost Best 23

24 Leveraging In-house Skills For Preventive Maintenance Pays! Hot water valve Bad valve seat leaking through even though the valve has a "full close" signal To return and relief dampers Outdoor air intake and damper HWS HWR CWS CWR Chilled water valve 57 F 65 F 75 F 52 F Return air leaking through the return damper due to linkage adjustment problem despite "Full Closed" signal being sent to the damper 75 F Mixed air plenum Relief air damper Relief air to building exterior Discharge controller arranged to modulate the chilled water valve, heating water valve and economizer dampers in sequence to maintain discharge temperature. Set for 57 F Out of calibration 55 F Supply fan (temperature rise due to fan heat) HWS HWR 60 F To other zones 60 F From other zones 75 F Comfortable space maintained by 60 F supply air from the reheat coil under the control of the thermostat 24

25 Leveraging In-house Skills For Preventive Maintenance Pays! To return and relief dampers 57 F Outdoor air intake and damper Return air damper properly adjusted for full closure at full stroke Hot water valve Seat repaired and properly adjusted HWS HWR CWS 57 F 57 F CWR Mixed air plenum Relief air damper Chilled water valve 57 F Relief air to building exterior Discharge controller arranged to modulate the chilled water valve, heating water valve and economizer dampers in sequence to maintain discharge temperature. Set for 57 F Properly calibrated 60 F Supply fan (temperature rise due to fan heat) HWS HWR 60 F To other zones 60 F From other zones 75 F Comfortable space maintained by 60 F supply air from the reheat coil under the control of the thermostat 25

26 Extended Surface Area Filters; Energy and NEB s in one package improvements in many areas Conventional Design Extended Surface Area Design Images from Viledon and Farr catalog literature 26

27 Extended Surface Area Filters; A Conventional Green Alternative Design for a Common Extended HVAC Surface Requirement Area improvements in many areas Design Reduced fan energy Less material Longer life = fewer filters to buy Reduced waste stream Longer life = fewer filters to dispose of Reduced labor Longer life = fewer filter changes = more time for ensuring green operation 27

28 Filter Performance Monitoring Change based on pressure drop a key component for success Consider experience at an Oregon semiconductor plant 100% outdoor air systems Loaded fastest over-all Loaded more quickly in spring and fall Loaded slowly in the winter 100% recirculation systems Loaded slowest over-all Economizer equipped systems Somewhere inbetween Loaded more slowly in the summer 28

29 Extended Surface Area Filter Life Cycle Cost Comparison; Two Year Window (Representative's Guaranteed Filter Life) Air handling unit flow rate Annual hours of operation Electrical rate Current prefilter Current final filter Current filter change-out schedule New prefilter New final filter New filter change out schedule Item Costs 66,570 cfm 8,760 (24 hours per day, 7 days per week) $0.120 per kwh Series 400 Standard Capacity MERV 7 Soniq Soft Pocket, 8 pocket MERV 9 3 months for prefilters and 12 months for final filters based on time None required F6 Rigide Pocket, 8 Pocket MERV months minimum based on pressure drop; 24 months guaranteed by the manufacturer Conventional Year 1 Extended Surface Area Year 2 (Guaranteed Life) Conventional Extended Surface Area Conventional 2 Year Total Extended Surface Area $ % of Total $ % of Total Filter Cost $3,101 $4,464 $3,101 $0 $6,202 29% of total $4,464 39% of total Labor Cost $624 $240 $624 $0 $1,248 6% of total $240 2% of total Energy Cost $7,068 $2,331 $7,068 $4,328 $14,137 65% of total $6,659 59% of total Total Cost $10,793 $7,035 $10,793 $4,328 $21,586 $11,363 Waste (cubic yards) Extended Surface Area Filter Savings Filter Cost Labor Cost Energy Cost Total cost Waste (cubic yards) ($1,363) $384 $4,738 $3,759 (3.6) $3,101 $624 $6,465 $1,738 $1,008 $2,740 $7,478 $10,224 (17.8) (21.3) 28% savings relative to conventional 81% savings relative to conventional 53% savings relative to conventional 47% savings relative to conventional 100% savings relative to conventional 29

30 A Knowledgeable, Formula for Improved Trained Life Operators Cycle Cost Given : ( Operations + MaintenancePreventive) Operator = Life Cycle CostBest Optimized and Operator Knowledge ( Operations + Maintenance ) Optimized Preventive = O & M Best Practices Substituting : O & M Best Practices Operator Knowledge = Life Cycle Cost Best 30

31 Owner/Operator Participation in O&M Activities Involving the operating staff Leverages system knowledge Teaches the procedures Connects concept with reality Foundation for persistence Helps control costs Focuses outside expertise Leverages internal expenditures See that! I forgot to tighten the nut. 31

32 Leveraging a Lesson Learned Interstitial cascades Upper distribution basins Lower collection basins 32

33 Leveraging a Lesson Learned There are instances where a pump supplies water to a pool that it does not return water from North Upper Level Pool South Upper Level Pool High level intake connection (typcial) Overflow to drain (typical) Eastern Lower Level Pool Manual Make-up Skimmer system and piping to and from sand filters 8" equalization line (typical of 1 on the South and 2 on the North) Northwest Lower Level Pool Intake screen (typical) Returns only to Pump 3 Stream Pump 3 (3rd in from the door) 1,000 gpm (nominal) Dr Returns only to Pump 4 Cross-over valve throttled approximately 50% (look for the mark on the locking quadrant) Plugged equalzation line to the front water feature. This line must remain plugged to prevent overflow at the front water feature due to the difference between operating water levels. Stream Pump 4 (4th in from the door) 1,000 gpm (nominal) Dr Automatic air vent (typical) Southwest Lower Level Pool Returns only to Pump 3 33

34 Semi-permeable Tube Inspection and Cleaning Kinetics (STICK) Annual savings 119,692 kwh; $14,611 Implementation cost $1,069 Simple payback 0.1 years North Upper Level Pool South Upper Level Pool High level intake connection (typcial) Overflow to drain (typical) Eastern Lower Level Pool Manual Make-up Skimmer system and piping to and from sand filters 8" equalization line (typical of 1 on the South and 2 on the North) Northwest Lower Level Pool Intake screen (typical) Plugged equalzation line to the front water feature. This line must remain plugged to prevent overflow at the front water feature due to the difference between operating water levels. Southwest Lower Level Pool Automatic air vent (typical) Stream Pump 3 (3rd in from the door) 1,000 gpm (nominal) Dr Cross-over valve throttled approximately 50% (look for the mark on the locking quadrant) Stream Pump 4 (4th in from the door) 1,000 gpm (nominal) Dr 34

35 Doing the Math Aggressive conservation program Embraced technology Supported O&M Training Preventive maintenance Empowerment 35

36 Doing the Math Memorial Hospital of Carbondale Historical Energy Consumption, ,000 70,000 60,000 Energy audit and Master Plan Development 400, , , ,000 0 Building Gross Sq.Ft. -100,000 50, ,000 Consumption, MmBtus 40,000 30,000 20, , , , , , , ,000 10,000-1,000,000-1,100, ,200,000 Year Gas Consumption, MmBtus Electric Consumption, MmBtus Other (Oil and Parking Lot Lighting Electrical) MmBtu 36

37 Doing the Math Memorial Hospital of Carbondale Historical Energy Consumption, ,000 70,000 60,000 Mechanical/Electrical retrofits and energy conservation projects 400, , , ,000 0 Building Gross Sq.Ft. -100,000 50, ,000 Consumption, MmBtus 40,000 30,000 20, , , , , , , ,000 10,000-1,000,000-1,100, ,200,000 Year Gas Consumption, MmBtus Electric Consumption, MmBtus Other (Oil and Parking Lot Lighting Electrical) MmBtu 37

38 Doing the Math 80,000 70,000 60,000 Memorial Hospital of Carbondale Historical Energy Consumption, Major expansion doubles gross square footage 400, , , ,000 0 Building Gross Sq.Ft. -100,000 50, ,000 Consumption, MmBtus 40,000 30,000 20, , , , , , , ,000 10,000-1,000,000-1,100, ,200,000 Year Gas Consumption, MmBtus Electric Consumption, MmBtus Other (Oil and Parking Lot Lighting Electrical) MmBtu 38

39 Doing the Math Memorial Hospital of Carbondale Historical Energy Consumption, ,000 70,000 60,000 Energy consumption is only slightly above what it was in , , , ,000 0 Building Gross Sq.Ft. -100,000 50, ,000 Consumption, MmBtus 40,000 30,000 20, , , , , , , ,000 10,000-1,000,000-1,100, ,200,000 Year Gas Consumption, MmBtus Electric Consumption, MmBtus Other (Oil and Parking Lot Lighting Electrical) MmBtu 39

40 Doing the Math 40

41 Why Do We Need O&M Best Practices? 41

42 Building are Complex, Prototypical Machines The Architectural Contract Documents The Mechanical Contract Documents Perhaps a clue about why there may be a few problems and where they are going to occur? 42

43 Building are Complex, Prototypical Machines Shop drawing sets that define the curtain wall and window system 43

44 Building are Complex, Prototypical Machines This project had over 2,700 RFI s A few problems shouldn t be a surprise they should be anticipated! Keeping things running smoothly will require Management support Budgetary support Knowledgeable, Trained, Inspired Operators 44

45 Resources 45

46 Resources 46

47 Knowledge is Power Reheat coil Preheat coil Cooling coil 47

48 Textbook Dehumdification Cycle Cactus Reheating Cooling Preheating 48

49 Cactus = Desert Desert = Low Atmospheric Moisture Hourly Weather Data November November Temperature, Dewpoint, F /1/05 11/29/05 12/27/05 1/24/06 2/21/06 3/21/06 4/18/06 5/16/06 6/13/06 7/11/06 8/8/06 9/5/06 10/3/06 10/31/06 Date and Time Drybulb Temperature, F Dew Point Dewpoint for a 75 F, 50% RH Space

50 Knowledge Saves Power 1,400 Average Daily Natural Gas Use for Starr Pass Account Facility IQ Site 337X6 1,200 1, Average Daily Natural Gas Use [therms] therms 2007 therms 2006 therms January February March April May June July August September October November December $15,000 + per year

51 Resources O&M resources from BetterBricks! 51

52 Resources Incentives for efficient replacements when O&M is no longer the answer! 52

53 Resources Free Downloads at 53

54 Resources Bill Coad s discussion of a new standard for professionalism in engineering that is to practice our profession with an emphasis upon our responsibility to protect the long-range interests of the society we serve and, specifically, to incorporate the ethics of energy conservation and environmental preservation in everything we do. 54

55 Resources on Filtration Articles by H.E. Barney Burroughs The Art and Science of Air Filtration in Health Care HPAC - October 1998 Filtration: An Investment in IAQ HPAC - August 1997 Specifying Filters HPAC - November 2003 Using Extended Surface Air Filters in Heating Ventilation and Air Conditioning Systems: Reducing Utility and Maintenance Costs while Benefiting the Environment, by Michael J. Chimack et.al., ACEEE 2000 Proceedings Understanding the 52.2 ASHRAE Test Method Presentation Air Filters Northwest

56 Retrocommissioning; O&M taken to the Next Level To improve and optimize a building s O&M. A Practical Guide for Commissioning Existing Buildings Tudi Haasl, Portland Energy Conservation, Inc. Terry Sharp, Oak Ridge National Laboratory 56

57 Commissioning Costs and Benefits Download it free of charge at: Costs-Benefits.html 57

58 Additional Quantifying Data on Nonenergy Benefits Non-Energy Benefits Including Productivity, Liability, Tenant Satisfaction, and Others: What Participant Surveys Tell Us about Designing and Marketing Commercial Programs Dennis Pearson, Seattle City Light Lisa A. Skumatz, Skumatz Economic Research Associates, Inc. Published at 2002 ACEEE Summer Study on Energy Efficiency in Buildings Expanded at 2004 ACEEE Summer Study 58

59 An On-line Resource Library for O&M Practices and More California Commissioning Collaborative

60 Take Advantage of Free Trade Publications Consulting Specifying Engineer Heating, Piping, and Air Conditioning Engineered Systems Electrical Apparatus htm NETA World 60

61 Take Advantage of On-line Resources Consulting Specifying Engineer Blogs 61

62 Watch for Web Based Training Opportunities Resources for the Resourceful Introduction and Resources for Understanding the Local Climate Presented By: David Sellers, Senior Engineer Facility Dynamics Engineering 62

63 Looking for Providers to Network or Work With? The Building Commissioning Association is the place to go! 63

64 Want to Learn More? Attend the upcoming 16 th National Conference on Building Commissioning April 22 24, Newport Beach, CA Learn Techniques Meet other Providers, Owners, and Researchers Share Ideas Attend the Trade Show Eat, Drink and Be Merry! Watch for details 64

65 Questions? Thanks for attending! Go make the world a better place 65