Yong%X.%Tao,Ph.D.,P.E.% … · wellspacing,1"pipesize@pump BR2 Tampa, FL Residen>al 1900 Open% Loop/Two Well 4 150welldepth,4"welldiameter100 wellspacing,1"pipesize@pump BR3 Pensacola,

Yong X. Tao, Ph.D., P.E. PACCAR Professor of Engineering and Chair University of North Texas (UNT) Yimin Zhu, Ph.D. Pulte Homes Professor of Construc@on Management Louisiana State University (LSU)

Analysis of Energy, Environmental and Life Cycle Cost Reduc@on Poten@al of Ground Source Heat Pump (GSHP) in

Hot and Humid Climate

October 15, 2014

2

About Texas/DFW

Dallas-Fort Worth, Texas • Equidistant to the continent’s five largest

business centers (New York, Chicago, Los Angeles, Mexico City and Toronto).

• Home to 29 foreign consulate offices. • DFW Airport serves 175 world destinations

and is world ranked 3rd in terms of operations and 8th in terms of passengers.

• 239 languages are spoken in DFW; English is not the primary language in about 1 of 5 DFW households.

• 44% of DFW residents are new Americans, including 1+ million that have moved here in the past decade.

3

Project Overview

Scope: Evalua@on of actual energy and cost performance for installed GSHP/HGSHP in hot and humid climate where buildings have much larger cooling needs than hea@ng needs annually: Are they performing as designed and beRer than the conven@onal systems? Poten>al: Net zero energy buildings in hot and humid climate: •  GSHP/HGSHP for energy efficient cooling/hea@ng •  High solar electricity produc@on

4

Accomplished Tasks:

•  DATA: Gather and analyze independent and sta@s@cally valid technical, cost, financial incen@ve data on installed GSHP/HGSHP applica@ons in residen@al and commercial buildings

•  Energy Model: Develop a calibrated baseline and performance period model of new construc@on and retrofiRed buildings using TRNSYS/EnergyPlus simula@on programs.

•  LCC Model: Develop a cost/benefit model and tool including life cycle cost (LCC) analysis of GSHP and HGSHP system based on data collected and correlate the data with iden@fied parameters

5

Building Selec>on

General Informa>on GSHP Informa>on

ID Loca@on Building Type

Floor Area ( \2)

Type of Loop

Total Capacity (tons)

Ground Loop Basic Dimensions

Case 1

Tampa, FL Residen@al 2663

Open Loop /

Two Wells 5 160 \ well depth

Case 2

Tampa, FL Residen@al 2550

Open Loop /

Two Wells 4 N/Aa

Case3 Tampa, FL Residen@al 3200

Open Loop /

Two Wells 5 100 \ well depth

Case 4

Tampa, FL Residen@al 16105 N/Ab

Non-monitored case studies

a. No well and pipe information is available. b. No system information is available.

6

Monitored case studies -‐ 8 buildings: 4 Residen@al /4 Commercial

General Informa>on GSHP Informa>on ID Loca>on Building Type Floor Area

(S2) Type of Loop

Total Capacity (tons) Ground Loop Basic Dimensions

BR1 Tampa, FL Residen>al 1600

Open Loop / Two

Well 3 80 S well depth , 4" well diameter60 S

well spacing , 1" pipe size @ pump

BR2 Tampa, FL Residen>al 1900

Open Loop / Two

Well 4 150 S well depth , 4" well diameter100 S

well spacing , 1" pipe size @ pump

BR3 Pensacola, FL Residen>al 2800

Closed Loop / Ver>cal

5 6 boreholes , 250 S depth-‐3/4" U-‐tube 1 1/4" pipe size @ pump

BR4 Robertsdale, AL Residen>al 2800

Closed Loop /

Horizontal 5 (2+3)

5 trenches-‐ 100S(L)*3S(W)*6S(D) 600S of 3/4" tube in each trench 1 1/4 " pipe

size @ pump

BC1 Pensacola, FL

Commercial / Opera>on Center

6000 Closed Loop / Ver>cal

19 17 boreholes , 300 S depth -‐ 3/4" U-‐tube 2" pipe size @ pump

BC2 Pensacola, FL

Commercial / Office 4250


13 (2X6+1) 14 boreholes , 300 S depth -‐ 3/4" U-‐tube 3" pipe size @ pump

BC3 Pensacola, FL

Commercial / Restaurant 13600


129 135 boreholes , 300 S depth -‐ 3/4" U-‐tube 10" pipe size @ pump

BC4 Pensacola, FL

Commercial / Hotel 80145

Closed Loop /

Ver>cal / Hybrid

340 (150 tons cooling tower)

96 boreholes , 200 S depth -‐ 1" U-‐tube 8" pipe size @ pump

7

BR3

BR4

8

BC2: Office Building

BC3: Restaurant

9

Typical Data collec>on

•  Three weeks GSHP field data: –  Schenitec ultrasonic Btu meter, which was installed on the entering and exis@ng

posi@ons of a water pipe to measure the water flow rate in the pipe. –  Fluxus ultrasonic Btu meter, that was installed on the main ground loop to

measure and log the heat transfer rate to the ground –  WaRnodes with Campbell Scien@fic data logger, which were installed to measure

and log the power consump@on of the heat pump systems in four mechanical room.

–  5 Hobo sensors to measure and log temperature and rela@ve humidity of inside and outside of the building and also before and a\er the coil in the monitored heat pump unit.

•  Total electrical consump@on data from u@lity bills. •  Building architecture drawings •  Local weather data

10

Ground source heat pump monitoring protocol

•  Heat transfer rate of the heat pump to the ground water •  Power consump@on of the heat pump •  Total heat transfer rate to the ground water ( For systems with

more than one heat pumps) •  Total power consump@on of the heat pump system ( For

systems with more than one heat pumps) •  Cooling/Hea@ng load of the heat pump coil (Op@onal: Due to

the availability of the monitoring equipment) •  Air temperature and humidity of the occupied areas of the

building •  Temperature and humidity of the outside air

11

Sensors and loggers for exis>ng systems

Parameter Suggested Measuring Device Suggested Data Logger Measuring Device Loca>on

Heat transfer rate to the ground water (Pipe diameter greater than 1 ¼

inch)

Fluxus F601 ultrasonic Btu meter Internal logger Inlet and Outlet of ground

water into HP/ground

Heat transfer rate to the ground water (Pipe diameter less

than 1 ¼ inch)

Schenitec STUFF-‐300F ultrasonic Btu meter SD-‐card data logger Inlet and Outlet of ground

water into HP/ground

Power consump>on

Waj Node Transducer WNA-‐1P-‐240-‐P (For 1

Phase powered buildings) WNA-‐3Y-‐208-‐P (For 3

Phase powered buildings)

Campell Scien>fic CR-‐206 Electrical Breaker Box

Cooling/Hea>ng load of the heat pump

coil HOBO Sensor* Internal logger Before and aSer heat pump

coil Air temperature and

humidity of the occupied areas of

the building HOBO Sensor Internal logger Occupied Area

Temperature and humidity of the outside air

HOBO Sensor Internal logger Outside of the building

12

Fuxus F601 Btu meter mounted on a pipe

WattNode transducer

HOBO sensor (Temperature/ Relative humidity) Campbell Scientific CR-206 data logger

13

Compara>ve Study: GSHP vs. Equiv. ASHP Building GSHP unit model Equivalent ASHP unit model

BR1 CLIMATE MASTER TTH038 (3 tons) Carrier 50TCQ A04(3 tons)

BR2 CLIMATE MASTER TTH049 (4 tons) Carrier 50TCQ A05(4 tons)

BR3 WaterFurnace Envision NDH064 (5 tons) Carrier 50TCQ A06(5 tons)

BR4 WaterFurnace 1-‐ E Series (E036) (3 tons) 2-‐ Versatec (2 tons)

Carrier1-‐HBC3 (2 tons) 2-‐50TCQ A04 (3 tons)

BC1 WaterFurnace Envision 1-‐ND064 (5 tons) 2-‐ND038 (3 tons)

Carrier 50TCQ 1-‐ A06 (5 tons) 2-‐A04 (3 tons)

BC2 WaterFurnace Envision NDH072 (6 tons) Carrier 50TCQ A07 (6 tons)

BC3 FHP EC series Carrier 50TCQ series

BC4 CLIMATE MASTER (Total 180 tons) Carrier (Total 180 tons)

14

Case Study: BR1 – Open-‐loop GSHP

•  TRNSYS connec@on map

Turn

Radiation

Weather data

Psychrometrics

Sky temp

Temperature

Building

Type114Type504b

Type108

Type25c

Type14d

Type14c

Type31b

Type501

Monthly-2

15

BR1: Equivalent Conven>onal Air Source Heat Pump

TurnTurnRadiation

Weather data

Psychrometrics

Sky temp

Building

Type65d

Type665-3Type108

TYPE24 Type25c

Monthly-2

16

Comparison (simulated vs. measured): GSHP

•  Annual Power Consump@on

•  Monthly

124.4 139.4

0 15 30 45 60 75 90 105 120 135 150

Measure_data Simula@on_data

Energy Consump>on

(kWh)

0 200 400 600 800 1000 1200 1400 1600 1800 2000 2200 2400

1 2 3 4 5 6 7 8 9 10 11 12

Monthly Electric

Consump>on (kWh)

Month

Simula@on_result Electric_bill

17

Comparison between GSHP and Equiv. ASHP

0.00E+00

5.00E+03

1.00E+04

1.50E+04

2.00E+04

2.50E+04

Total_with GSHP Total with ASHP

Annual Energy Consump>on

(KWH) Equip.

Ligh@ng

HVAC

18

HGSHP Schema>c diagram

Background •  Disadvantage of GSH

–  High ini@al cost –  Load imbalance increases the

ground temperature specially in hot climate

•  Advantage of HGSHP –  Lower ini@al cost –  Handle excess heat rejec@on

load to ground

•  Disadvantage of GSH –  Addi@onal maintenance cost –  Complicate opera@on control

Case Study: BC4 -‐ HGSHP

19

Southwest view of the HGSHP building

Construc>on Summary •  Loca@on: Pensacola, FL •  Building type: Hotel •  117 rooms, constructed in

2002

BC4 Building Specifica>on

Construc>on Detail

Floor area(m2) 7959

Number of floor

5

Exterior wall layer

Gypsum board 2” Concrete block stucco 12”

Exterior insula@on and finish

Roof layer R-‐19 insula@on, 6” STUD

Glazing U-‐Value

U-‐2.89 W/m2k

Building informa>on

20

•  300-‐ton hybrid GSHP –  150ton evapora@ve fluid

cooler –  150 ton GHX

•  HVAC –  Unitary heat pump, roof top

unit for room, public area –  Water to Water heat pump for

ice machines and pool and spa hea@ng

•  40 HP pumps in main condenser loop

HVAC Specifica>on

HVAC System Detail

HVAC 180 tons unitary heat pump

81 tons water to water heat pump

50 tons roof top air condi@oner

Condenser loop

GPX (150tons)

98@200\

I in U-‐tube

Cooling tower (150tons)

Evapora@ve fluid cooler

HVAC descrip>on

21

Southwest view of the HGSHP building

HGSHP Loop Schema>c •  Loca@on: Pensacola, FL

Simula>on Model

Building Geometry Model

Energyplus Loop Descrip>on

22

Model Calibra>on

100% OA Roof Top

AC 7%

Other Electrical Energy

Consump>on 65%

SPA and DHW 8%

Main Loop Pumping 18%

Cooling tower 2%

Simula>on Result

Cooling tower 2%

RooSop AC 7%

SPA and DHW 7%

Main loop

pumping 17%

Other Electrical Energy

Consump>on 67%

Actual U>lity Data

0

5

10

15

20

25

30

35

40

1 2 3 4 5 6 7 8 9 10 11 12

Average entering water temperature

(deg C)

Month

simulated data measured data

*TRNSYS

23

Comparison of Annual Energy Consump>on

•  Compare annual energy consump@on –  GHP –  HGSP –  ASHP

Simula>on Result

0

100000

200000

300000

400000

500000

600000

700000

GHSP HyGSHP ASHP

Annual energy consump>on

(Kwh)

24

Life Cycle Cost Analysis Considera>on

•  The Main Cost Variables for LCC analysis –  Ini>al Cost –  Electricity Cost – Maintenance Cost –  Replacement Cost

•  Addi>onal Cost Parameter –  Incen>ves –  Electricity Rates –  Discount Rates –  Life Cycle –  Residual Value of GSHP system

25

Data Types and Sources

Type Poten>al Source

GSHP System Conven@onal System

Ini>al Costs Survey of the owners Standard data with input from contractors

Maintenance Costs Standard data and literature

Standard data

Replacement Costs Survey of the owners, standard and literature

Standard data

Electricity Consump>on Owner’s electricity bill and simula@on

Simula@on

Incen>ves Federal government and local power company

N/A

Electricity Rate Local power company and historical data

Local power company and historical data

Discount Rate Literature Literature

26

Life Cycle Cost Analysis: BC4

Ini>al Cost ($)

Maintenance Cost ($)

Periodic Cost ($)

Annual Electricity

Cost ($)

Tax Credit ($)

U>lity Rebate ($)

GHSP 874,900 20,988 425,463 47,390 262,470 102,000

Conven>onal 801,450 54,595 772,071 50,259

Year Without Incen>ve

GSHP NPV ($) Conven>onal NPV ($)

Total (Mean) 2,529,348 3,457,207

Year With Incen>ve

GSHP NPV ($) Conven>onal NPV ($)

Total (Mean) 2,252,921 3,457,041

Cost Data for GSHP and ASHP system

LCC Analysis Result

Life: 20 years Parts Replacement for ASHP: Every ten years

27

HGSHP System and Conven>onal System

$0

$500,000

$1,000,000

$1,500,000

$2,000,000

$2,500,000

$3,000,000

$3,500,000

$4,000,000

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31

GSHP Conven@onal

$0

$500,000

$1,000,000

$1,500,000

$2,000,000

$2,500,000

$3,000,000

$3,500,000

$4,000,000

$4,500,000

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31

GSHP Conven@onal

Without Incen>ves With Incen>ves

Cumulative Net Present Value Comparison

28

Ra>o Sensi>vity Analysis without Incen>ves: BC4

HGSHP HGSHP Conven>onal Conven>onal Ini>al Cost $ 874,900 107% $ 801,450 -‐117% Energy Cost 976,255 96% 1,035,351 -‐91% Maintenance Cost 432,568 217% 1,124,676 -‐83% Replacement Cost 235,569 398% 495,563 -‐189% Total 2,519,291 3,457,041

Conclusion: For commercial systems, without incentive, HGSHP is better than the conventional one. Costs are not sensitive to change the conclusion

29

Ra>o Sensi>vity Analysis without Incen>ves: BR3

Year Without Incen>ve With Incen>ve

GSHP NPV Conven@onal NPV GSHP NPV Conven@onal NPV Total $ (Mean) 41,347 36,952 32,647 36,952

Life Cycle Cost Analysis

GSHP GSHP Conven>onal Conven>onal Ini>al Cost $ 25,000 -‐18% $ 11,536 38% Energy Cost 11,166 -‐39% 17,085 26% Maintenance Cost 1,557 -‐282% 4,049 109% Replacement Cost 3,623 -‐121% 4,282 103% Total $ 41,347 $ 36,952

Conclusion: In order to compete for residential systems, the initial cost must decrease (justification for incentive), or energy cost increases. Costs are sensitive to swing the observation.

30

Summary of addi>onal studies

BR3: COP and LCR (load/consump@on ra@o)

0

2

4

6

8

0 20 40 60 80 100 120 140 Time Interval Indicator

31

BR3: EnergyPlus and TRNSYS

0

200

400

600

800

1000

1200

1400

1600

1 2 3 4 5 6 7 8 9 10 11 12

Monthly Electric Energy

Consump>on (KWh)

Month

ENERGYPLUS Actual Electric Consump@on TRNSYS

32

Energy Saving compared to conven>onal equivalent

1187 1852 3265 1300 8361

3009

15100

39397

0

10000

20000

30000

40000

50000

BR1 BR2 BR3 BR4 BC1 BC2 BC3 BC4

Annu

al ene

rgy saving

(kWh)

13.9 18.6

34.6

13.6 17.2

13.5 9.2

5.7

0

5

10

15

20

25

30

35

40

BR1 BR2 BR3 BR4 BC1 BC2 BC3 BC4

Energy sa

ving (%

)

33

Summary and Conclusions

•  Residen@al applica@ons: –  The case studies show that the applica@on of GSHP systems to residen@al buildings is more uncertain than commercial/office buildings. This may be because the ini@al costs are rela@vely too high and the savings from energy costs cannot easily offset the ini@al costs in residen@al applica@ons.

–  Incen@ves, in this case, are cri@cal to make residen@al applica@ons feasible.

–  It appears that ini@al costs and energy costs are rela@vely more sensi@ve than maintenance costs and replacement costs. Thus, the rising energy costs may become a driver for more GSHP applica@ons as well in the future.

34


•  Commercial/Office Applica@ons – All case demonstrated favorable results for GSHP applica@on even without incen@ves.

– The applica@on of incen@ves helps to reduce payback @me.

–  In such applica@ons, it seems that some@mes maintenance costs may become more sensi@ve than ini@al costs or energy costs.

35


•  Case Study – HGSHP op@on shows more favorable than the conven@onal system

•  GSHP/HGSHP in Hot and Humid Climate – Good poten@al, especially for Commercial Applica@on

36

Acknowledgements

•  Dr. Rambod Rayegan, Ph.D. student at FIU and later the Post-‐Doctoral Associate at UNT

•  Dr. Junghyon Mun, Post –Doctoral Research Associate at UNT

•  Mr. Jiang Zhu, Master student in FIU and UNT •  Dr. Teshome Jiru, Post-‐Doctoral Fellow at FIU •  Mr. Sebas@an Munera, Master student at FIU •  Mr. Ce@n Canbek, Master student at FIU •  Mr. Shivam Phadtare, Master student at FIU

37

External Collaborators and Partners

•  Dr. Xiaobing Liu, Oak Ridge Na@onal Lab, Oak Ridge, Tennessee, formerly at ClimateMaster, Inc., Oklahoma City, Oklahoma

•  Mr. Keith Swilley, Gulf Power Company, Pensacola, Florida •  Mr. Jay Egg, Egg Geothermal Air Condi@oning and Pool Hea@ng,

Tampa, Florida •  Mr. C. V. Craig Muccio, Florida Power and Light Company,

Miami, Florida

38

Case 1 – BR1

ID Building Size (sf)1

System Tonnage (ton)2

Life Cycle (year)3

Geothermal System

Ini@al Cost ($)4

Tax Credit ($)5

U@lity Rebate ($)6

Maintenance Cost ($)7

Periodic Cost ($)8

Annual Electricity Cost

($)9 BR1 1,600 3 30 29,600 8,880 900 43.2 4,620/ 20 years 790

Cost data for the GHSP System

Notes: 1, 2, 4, 5 and 6 are derived from survey; 3 is assumed; 7 and 8 are estimated based on RS Means data and literature; 9 is derived based on the simulation of electricity consumption and electricity rate prediction.

ID Building Size (sf)1

System Tonnage (ton)2

Life Cycle (year)3

Conven>onal

Ini@al Cost ($)4 Maintenance Cost ($)5 Periodic Cost ($)6 Annual Electricity

Cost ($)7 BR1 1600 3 30 6,592 112.32 4,540/15 years 910

Cost data for the Conventional System

Notes: 1 and 2 are derived from survey; 3 is assumed; 4, 5, and 6 are estimated based on RS Means data and literature; 7 is derived based on the simulation of electricity consumption and electricity rate prediction.

39

Case 1 – BR1


GSHP NPV Conven@onal NPV GSHP NPV Conven@onal NPV Total (Mean) 49,249 34,725 40,512 34,725


GSHP GSHP Conven>onal Conven>onal Ini>al Cost 26,125 56% 6,592 220% Energy Cost 19,676 74% 22,841 64% Maintenance Cost 890 1632% 2,314 628% Replacement Cost 2,558 568% 2,978 488% Total 49,249 34,725

Ratio Sensitivity Analysis without Incentives

40

Case 2 – BR2



ID Building Size (sf)

System Tonnage (ton)

Life Cycle (year)

Geothermal System Ini@al Cost ($)

Tax Credit ($) U@lity Rebate ($)


Periodic Cost ($)

Annual Electricity Cost ($)

BR2 1900 4 30 27,666 8300 1200 51.3 6,10420 years 1,045



Life Cycle (year)

Conven>onal

Ini@al Cost ($) Maintenance Cost ($) Periodic Cost ($) Annual Electricity Cost

($) BR2 1900 4 30 7,828 133.38 6,187/15 years 1,285

41

Case 2 – BR2




GSHP GSHP Conven>onal Conven>onal Ini>al Cost 21,303 29% 7,828 80% Energy Cost 21,528 29% 26,462 24% Maintenance Cost 1,057 592% 2,748 228% Replacement Cost 3,380 185% 3,971 158% Total 47,267 41,009


42

Case 3 – BR3





Life Cycle (year)




Periodic Cost ($)


BR3 2,800 5 30 25,000 7,500 2,000 75.6 6,545/20 years 576



Life Cycle (year)

Conven>onal


($) BR3 2,800 5 30 11,144 196.56 6,671 829

43

Case 3 – BR3






44

Case 5 – BC1





Life Cycle (year)




Periodic Cost ($)


BC1 6,000 19 30 87,500 26,250 7,600 1,572 28,864 4,919



Life Cycle (year)

Conven>onal


($) BC1 6,000 19 30 60,000 4,087 34,156 7,183

45

Case 5 – BC1






46

Case 6 – BC2





Life Cycle (year)




Periodic Cost ($)


BC2 4,250 13 30 72,555 21,767 3,900 1,115 19,795 2,530



Life Cycle (year)

Conven>onal


($) BC2 4,250 13 30 42,500 2,895 24,905 2,885

47

Case 6 – BC2






48

Case 7 – BC3





Life Cycle (year)

Geothermal System

Ini@al Cost ($)

Tax Credit ($)

U@lity Rebate ($)


Periodic Cost ($)


BC3 13,600 129 30 538,148 161,444 38,700 3,563 216,186 19,180



Life Cycle (year)

Conven>onal


($) BC3 13,600 129 30 340,000 9,264 648,786 21,133

49

Case 7 – BC3


GSHP NPV Conven@onal NPV GSHP NPV Conven@onal NPV Total (Mean) 1,126,370 1,382,631 961,025 1,382,631


GSHP GSHP Conven>onal Conven>onal Ini>al Cost 538,148 48% 340,000 75% Energy Cost 395,125 65% 435,351 59% Maintenance Cost 73,403 349% 190,849 134% Replacement Cost 119,694 214% 416,431 62% Total 1,126,370 1,382,631


50

Case 8 – BC4





Life Cycle (year)

Geothermal System

Ini@al Cost ($)

Tax Credit ($)

U@lity Rebate ($)


Periodic Cost ($)


BC4 80,145 340 30 874,900 262,470 102000 20,988 425,463 47,390



Life Cycle (year)

Conven>onal


($) BC4 80,145 340 30 801450 54,595 772,071 50,259

Documents

Yong%X.%Tao,Ph.D.,P.E.% … · wellspacing,1"pipesize@pump BR2 Tampa, FL Residen>al 1900 Open% Loop/Two Well 4 150welldepth,4"welldiameter100 wellspacing,1"pipesize@pump BR3 Pensacola,