HVAC SYSTEMS. Presented to. Waste Reduction And Technology Transfer (WRAT. Presented by. Gerald R. Guinn, Ph.D.

Transcription

1 L OPPORTUNTES FOR ENERGY CONSERV. N HVAC SYSTEMS Presented to Waste Reduction And Technology Transfer (WRAT Presented by Gerald R. Guinn, Ph.D. The University of Alabama in Huntsville Johnson Research Center April 25, 1995 fie University of Nk6ama in

2 EXAMPLE ENERGY SAVNGS (1) Reduce the flow of oversized fan or pump 25% Horsepower is reduced by 58% At 5$/kWh, it costs $360/yr/BHP to operate full time A 40,000 cfm fan requires Hp and costs $6,207/yr to operr At 30,000 cfm fan requires 7.27 Hp costing $2,61O/yr to operate NET SAVNGS - 6,207-2,610 = $3,597/year RETROFT COST = New Pulley

3 L v EXAMPLE ENERGY SAVNGS (2) Reducing condensing water temperature increases chiller perforbance 1 A 1,000 ton chiller requires approximately 1 kw/ton and operatc hrs. in Birmingham i at 2,000 Cost of operation is $100,000/year Resetting condenser water temperature from 85 F to 83 F performance by 5% improves NET SAVNGS = $5,000/year RETROFT COST = Nil

4 ENERGY AND COST SAVNGS STRATEGBS Reduce the Requirement for Energy mprove System Efficiency mprove the System Operation Reduce the Cost of Energy

5 L BULDNG RELATED ECO S 1 solate Unoccupied Areas Roof Sprays nstall Curtains at Loading Docks Consider Cooling Garments Eliminate Building Negative Pressure

6 MAJOR COMPONENTS OF HEATNG LOAD c

7 "MAJOR COMPONENTS OF XR CONDTONNG LC SUMMER W'F autdmr air temperature air condilianer (sensible and latenl) Air conditioner 111 applicable) around doors. andwindows

8 Figure 25. nfilmation through Doors 4-82

9 4-83

10 - - - THS VESTBULE ARRANGEMENT MNMZES PROJECTON WALLS MAY BE OPAOUE OR 7 TRANSPARENT N N REMOVE EXSTNG - DOORS Figure 24. Typical Vestibule Arrangements 4-8 1

11 . cfmlft of crack Figure 31. Rate of nfilfration Through Window Frames 4-10]

12 ELMNATE BULDNG NEGATVE PRESS JRE LOW VELOCTY EXHAUST (HGH VOLUME) - BEFnFlE HGH VELOCTY EXHAUST THRU SLOT (LOW VOLUME) AFTER NTRODU MAKE-UP CLOSE T( 3 OOD

13 PO am- SAVXdS 'do08

14 COOLNG GARMENTS

15 &AC SYSTEM EFFCENCY MPROVEMENTS (CW) - Economizers - Outside Air With Enthalpy Control - Precool Return Air With Cooling Tower - Chilled Water Free Cooling With Cooling Tower - Refrigerant Migration Free Cooling Chilled Water Reset Discriminator Control Condenser Water Reset Cooling Tower Alternatives Ground Loop Well Water - Lake Water Off-peak Storage (Water)

16 a 0 r= 2 w 0 v)

17 - -4 REWORKNG OUTC-OR AR DAMPERS NEW OP OSED BLADE SZED FOR REQUREMENTS COL / PRE-HEAT COll AFTER - m j JOMZER CYCLE HERE OR BLANK :ONOMZERs CYCLE i NOT USED

18 i 1 '-).../ \ - n a r x W i

19 DFFERENTAL ENTHALPY MNTROL OF ECONOMZE4.--, / FROM SUPPLY FAN STARTER CONTROLLER T181 T3 ARE WET BULB OR DEW PONT TEMP SENSORS. T2 81 T4 ARE DRY BULB TEMPERATURE ENTHALPY CONTROLLER NCLUDES AR SElTlNG

20 COOLNG PLANT ENERGY REQUREMEP.TS 90,000 ft2 Garment Manufacturing Facility Without Economizer With Economize,

21 L TREATNG RECWULATED AR TOLET EXHAUST i

22 Er:?

23 L NDRECT EVAPbAATlVE COOLER ("Energy Recovery Equipment and Systems'SMACNA 7 0 AR NTAKF -- YAR NTAKE DRY PASSAGE

24 RUN-AROUNU SYSTEM USED TO RECOVER EXHAUST H AT ("Heat Recover Engineering Seminar", The Trane Compal BY) COL LOOP r FULL ECONOMZER CONTROL - OlSCRlMlNATOR CON1 ROL r J

25 L REFRGERANT MGRuTON FREE COOL.NG., t 3 QPWTon i

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28 HEAT RECOVERY FROM WATER CHLLERS U TOWER CONTROL -. STAT

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30 DOUBLE-BUNDLE CONDENSER HEAT RECCVERY

31 Reduction in condensing temperature Figm 39. Effect of Condensing Temperature on Chiller COP 4-56

32 CONDENSER WATER RESET DMerermal ( _ Prwur g* Cooling Tower Bypem VerlableSpeed Condenser Watm Pump

33 40' " Leaving chilled water temperature - F Figure 36. Effect of Chilled Water Temperaturt On Chiller COP 4-49

34 . i

35 ~ - C h i e r C W Sump 3-way bypass valve located at air washer.-- Constant volume primary, variable secondary llu! tration 16

36 - C h i e r - - C W Sump 19 Variable speed primary, no secondary Constant pressure, variable flow (New chiller) 1111 stratlon 19-2

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38 EFFECT OF STORAGE ON SYSTEM DESGN Chiller Storage Chiller - On System Size - Tons Ton Hours kw No Storage Full Storage Peak kwh Partial Storage Demand Limiteda Load Levelinga a. The terms demand limited and load leveling refer to the impact of the storage operation on the electric use pattern of he building, not to the cooling loads.,.

39 .

40 . / --

41 i ii REPLACE HGH RESSTANCE DUCT SECTON

42 ~. 2 3 a U W c 0" 0 m

43 BYPASS FOR OFF LNE CHLLERS / NSTALL NEW SOLATNG VALVES SET TO CLOSE WHEN CHLLER S OFF LNE. - 1 C---< /.a r- - J \J/ 55' F 51' F (HGH TEMPERATURE DUE TO BY-PASS EFFECT) \ CONSDER SPEED CONTROL OR ADDTONAL LOW VOLUME PUMPS NTERLOCKED WTH CHLLERS CHLLED WATER TOlFROM SYSTE c -

44 k HVAC SYSTEM EFFCENCY MPROVEMENT i (DX) Economizers - Outside Air With Enthalpy Control - Precool Return Air Evaporatively Cool Condenser Air Add Evaporative Condenser Add Water Cooled Condenser - Cooling Tower - Ground Loop - Well Water - Lake Water

45 b m - u

46 EVAPORATVE COOL CONDENSER A AR FROM SPACE

47 2 w 2 w z a 0 u.

48 ADD WATER COOLED CONDENSER COOL SUPPLY AR TO CONDTONED SPACE - HEATEXCHANGER REFRGER ANTiAlR (EVAPORATOR) COOL SUPPLY AR TO CONDTONED SPACE ianqer 4NTAR 4TOR) -WARM RETURN AR FROM CONDTONED SPACE RM RETURN AR FROM JNDTONED SPACE t COMPRESSOR WATER COOLED CO inser TOiFROM HEAT SNK

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50 HYDRONC HEAT PUMP SYSTEM ("Heat Recovery Engineering Seminar", The Trane Compar i.d

51 RUN-AROUND COL HEAT RECOVERY L Tc1 R.A. 3 -WAY VALVE LO-PRESS SELECTOR U

52 REDUCE COMPRESSOR AR NTAKE TEMPERATURE f Temperature Air ntake, of F ntake Volume Required to Deliver 1000 cu ft of Free Air at 70 F

53 L v S Y LOWERED DSCHARGE PRESSURE, PSG Single Stage Rcciprocatinp and Rotary Screw Compressors TWO Stage Reciprocnting and Cmtrifupl Compresors

54 t REDUCE COMPRESSOR AR NTAKE TEMPERATURE Temperature of Air ntake, F ntake Volume Required to Deliver 1000 cu ft of Free Air at 70 F

55 L 4 (Herbert Wendes). Keep.t Maintained Clean t Seal t Adjust t Lubricate t Keep t Unobstructed Recalibrate Check Control Settings Check Speeds Check Flows Keep Valves, Dampers, Etc. Operating Smoothly ron 11. Reduce Heating And Cooling Loads Reduce Space Temperature Settings in Winter, nc Summer Reduce Minimum Outside Air Reduce Lighting Loads -ease in

56 f Provide Maximum Economical nsulation Double or Triple Glaze Windows Seal Building nfiltration and Exfiltration Leaks Provide Window Protection Against Solar Radiation Reduce Absortivity of Walls and Roof With Lighter Control Temperature Stratification of Air in Spaces 111. V. V. Turn t Off When Not n Use Turn OnlOff At Optimum Times Reduce Flows n Air And Hydronic Systems Reduce Resistances n Air And Hydronic Systems Use More Efficient Equipment Higher SEER S Lower kw s Per Ton 0 Higher Seasonal C.O.P. s Lower Pressure Drop Avoid Over Sized Equipment Minimize Cycling, Use Correct Size Equipment Use Staging of Compressors, Boilers, Coils, Etc. L

57 V. V. V. X. mprove Efficiencies of Systems Use Variable Air Volume Use Variable Water Volume Avoid Simultaneous Heating and Cooling Use Temperature Resets mprove, Update Controls Sensors Control Motors Controllers Stats Valves, Dampers Use Computer Controlled Equipment EMS Control Units EMS Modular Units Dedicated Equipment Micro Processors Timers Set Backs, Set Ups Recover Waste Heat

58 t X. X. Use Natures Free Energy Outside Air For Cooling Ground Water Solar Heating Test And Balance Systems For Maximum Efficiency X. X. VX. Perform Valid Audit As Basis of Retrofit Before Startir Saving Measurers Obtain Thorough and Accurate nformation on Consumption, Systems, Operations and Conditions B Make Thorough and Reliable Engineering an Calculations Before Considerate Various Alternates Start With No Cost And Low Cost Energy Savings Measi Monitor, Adjust, Modify As Needed Energy Actual fore costs res