Geo 101 v09. Introduction to Geothermal Heat Pump Systems Conference. Geothermal Heat Pump Technology. Geothermal Heat Pump System Types

IOWA HEAT PUMP ASSOCIATION Geo 101 – v09 Introduction to Geothermal Heat Pump Systems Curtis J. Klaassen, P.E. 2009 Conference Iowa Energy Center En...
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IOWA HEAT PUMP ASSOCIATION

Geo 101 – v09 Introduction to Geothermal Heat Pump Systems Curtis J. Klaassen, P.E. 2009 Conference

Iowa Energy Center Energy Resource Station

Geothermal Heat Pump Technology „ Introduction „ Geothermal Heat Pump System Types „ Geothermal System Features ● Pros and Cons ● Applications

„ Geothermal System Economics „ A Residential Perspective

Questions at Any Time……

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The Iowa Energy Center Advancing Iowa’s Energy Efficiency and Renewable Energy Use Through Research, Demonstration and Education Projects:

„ Provide balanced energy information

Energy Resource Station, Ankeny Biomass Energy Conversion Facility, Nevada „ Support community, business and individual Grants efforts with Research, Education & Demonstration energy efficiency & renewable energy Alternate Energy Revolving Loan Program

„ Serve as a resource for energy issues, research & technology

„ Administer Alternative Energy Revolving Loan Program

www.energy.iastate.edu

Building Energy in Perspective „ Buildings Use 40% of the Nation’s Primary Energy Total Residential & Commercial = 40%

22% 28%

Residential Commercial 18% 32%

Industry Transportation

„ Buildings Use 72% of the Nation’s Electricity „ Responsible for 39% of the Nation’s Greenhouse Gas Emissions 2007 Building Energy Databook

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Energy Efficiency – Building Blocks „ Step 1 – Reduce Energy Load ● Site Orientation and Building Arrangement ● Efficient and Effective Building Envelope

„ Step 2 – Improve Efficiency of Systems and Equipment ● ● ● ●

HVAC Systems – Geothermal Systems Lighting Systems – Daylighting Efficient A/C units, Boilers, Motors, Light Fixtures Computers and Office Equipment

„ Step 3 – Effective Building Operations ● ● ● ●

Proper Control – Energy Management Systems Commissioning – Making it work Operations and Maintenance – Training and Tune-ups Leverage Utility Company Rate Schedules

„ Step 4 – Alternative Energy Sources ● Renewable Energy Options – Solar, Wind, Biomass

What Is Geothermal Energy? „ Geothermal Energy is defined as “energy from the internal heat of the earth” ● 47% of the incoming radiation from the sun is absorbed by the earth ● The remainder is absorbed by the atmosphere or reflected back into space

„ Translated: Geo-Thermal means “Earth-Heat” „ “High Temperature” Geothermal Energy ● Energy Source for Hot springs and geysers ● Temperatures exceed 300°F ● Converted to produce useable heat and electricity

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“Low Temperature” Geothermal Energy „ Heat Energy contained near the surface of the Earth „ Shallow Earth temperatures fluctuate with seasonal outside air temperature „ Nearly constant Earth temperatures at depths below 15 feet „ Temperatures start to increase at depths below 400 feet about 1 °F per 100 feet Ground Surface 5 Foot Depth 10 Foot Depth 15 Foot Depth

Low Temperature Geothermal Energy „ Geothermal Heat Pump Systems ● Take advantage of “Low Temperature” Geothermal Energy ● Constant Temperature Year Around – 50 to 55°F in Iowa ● Apply a Water Source Heat Pump to “amplify” the heat energy

„ AKA ● ● ● ● ●

Ground Source Heat Pumps Earth Coupled Heat Pumps GeoExchange Systems Well/Ground Water Heat Pumps v.s. High Temperature Geothermal

Courtesy IGSHPA

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What are Heat Pumps? COOLING MODE

„ Heat Pumps Use a Refrigerant Cycle ●

Same operation as a Refrigerator or Air Conditioner



Compressor works to “pump” the refrigerant from “cold” to “hot”



Heat Energy is transferred through Heat Exchangers



The addition of a Reversing Valve allows the heat pump to work “backwards”



In Heating Mode – heat is pumped into the space rather than out

EXPANSION VALVE

COOL SUPPLY AIR

FAN

EVAPORATOR HEAT EXCHANGER

CONDENSER HEAT EXCHANGER

WARM RETURN AIR

COMPRESSOR CIRCULATING PUMP

„ Pump Heat rather than creating heat by burning fuel GROUND HEAT EXCHANGER

What are Heat Pumps? „ Characterized by Type of Heat Source and Heat Sink ● Air to Air or Air Source ● Water to Air or Water Source ● Water to Water ● Ground Source or Geothermal

„ Capable of Heating, Cooling and producing Hot Water ● Capacity measured in tons ● One ton of capacity = 12,000 BTU per hour ● Typical new home is about 4 tons of heating capacity & 2 tons cooling ● Typical Classroom is about 2 – 3 tons of heating or cooling capacity

„ What is a BTU?

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Geothermal Heat Pump System Three Basic Components: „ Heating/Cooling Delivery System ●

Traditional Ductwork / Piping system to deliver heat throughout the building

„ Heat Pump ●

Mechanical Unit that moves heat from the working fluid, concentrates it, and transfers the heat to the circulating air

„ Ground Heat Exchanger ●

Underground piping system that uses a working fluid to absorb or reject heat from the ground

Geothermal System Types „ Closed Loop System ● ● ● ●

Buried HDPE Piping Underground Heat Exchanger Circulating Fluid contained Exchanges only Heat with the Ground ● Various Configurations

„ Open System ● Ground Water from Well ● Exchanges Heat and Water with the Ground ● Returns Water to the Ground ● Direct Circulation – Lake or River

„ Special Systems ► City Water Interconnect Systems ► Hybrid Systems

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Horizontal Trench Loop „ Cost effective when land area is plentiful „ Needs 2500 square foot Land area per ton „ Trench depth – Six feet or more GEOTHERMAL PIPE

Courtesy IGSHPA

„ To Produce 1 ton of capacity: ● Trench length – typically 300 feet ● Pipe length – out & back = 600 feet

Horizontal Loop Three Circuits – each with Four Trenches and 4 pipes in each trench

2 inch Headers 3 Circuits

12 Horizontal Trenches Each 300 foot long with Four ¾ inch pipes

Nominal 24 Ton Arrangement

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Slinky Loop

Slinky Coil – Overlap

Slinky Coil – Extended

„

To Produce 1 ton of capacity: ● ●

Trench length – typically 125 feet Pipe length – out & back = 700 – 800 feet

Courtesy IGSHPA

Slinky Loop

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Vertical Bore Loop „ Keeps Space required to a minimum „ Needs 250 Square Feet Land area per ton „ Bore Depth – 100 to 300 feet „ Bore Diameter – about 4 to 5 inches „ Bore Spacing – 15 to 20 feet apart „ Nominal Capacity – One ton / 200 ft Bore Hole

Vertical Boring Methods

Courtesy IGSHPA

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Vertical Boring Methods

Courtesy IGSHPA

Vertical Bore Grouting „ Grouting of Vertical Bore Holes Required ● Seal Borehole to Protect Underground Aquifers ● Maintain Thermal contact between pipe and ground ● Allow movement of pipe

„ Grout Types ● Bentonite Based ● Thermally Enhanced ● Cement Based

„ Pressure Grouting from the bottom up recommended

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Vertical Loop

3 Circuits with 8 Bores each Circuit

2 inch Header Pipes

Nominal 24 Ton Arrangement

200 foot Deep Vertical Bores with ¾” Pipes

Horizontal Bore „ Horizontal / Directional Boring Machine used ● Horizontal length typically 200 feet for one ton of capacity ● Bore depth controlled at depth ~ 15 feet ● Possible to stack horizontal bores at various depths ● Minimal disturbance to topsoil and landscaping

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Horizontal Bore

Pond Loop „ Most Cost Effective closed loop design „ Pond Depth – 12 – 15 ft minimum maintained depth „ Pipe Length – One 300 ft. coil per ton (minimum) „ Nominal Capacity – ● Heating: 10 tons/acre of pond ● Cooling: 20 tons/acre of pond

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Pond Loop

2 Tons 3 Tons 4 Tons

Pond Loop Installation

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Open Loop „ Most Energy Efficient System Option „ Very Cost Effective, providing the following are verified: ● Water Quality is High ●

Water Quantity is Sufficient



Meets Codes and Regulations

„ AKA “Pump and Dump” ● 1.5 to 2 GPM per ton required ● At 30% run time a 4 ton unit could use 100,000 gallons per month ● Typical Family of Four uses about 6,000 gallons per month for domestic purposes

Geothermal System Features

Energy Pros and Cons

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Geothermal System Features „ Energy Pros + Geothermal Heating Contribution ● 1 kW electricity plus 3 kW geothermal heat moved from the earth = 4 kW heat delivered ● Heating COP of 3.5 to 4.9

+ Geothermal Cooling Contribution ● Earth temperature sink cooler than air temperatures = reduced cooling compressor work ● Cooling EER of 14 to 27 (on 2 speed units)

+ Individual units allow zoning for off hour use + Reduced energy consumption: 30% - 50% less + Lower energy costs: 20% - 30% less

Geothermal System Features „ Energy Cons − Economizer Free Cooling not normally available − Ventilation/make up air energy handled separately

„ Energy Considerations = Distinction between EER and SEER = Minimize Circulating Pump energy = Evaluate Heat Recovery Options for Outside Air / Ventilation Air

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Energy Considerations „ Heat Pumps – Ground Source ● Heating Efficiency measured by COP (Coefficient of Performance) ● Cooling Efficiency measured by EER (Energy Efficiency Ratio) ● Performance ARI/ASHRAE/ISO Certified at Specific Temps and Conditions

Efficiency Rating ARI / ASHRAE / ISO 13256 - 1

Closed Loop COP @ 32°F

Open Loop

EER @ 77°F

COP @ 50°F

EER @ 59°F

Best Available

4.9

27.0

5.5

31.1

High Efficiency

3.6 +

16.0 +

4.6 +

20.0 +

Low Efficiency

2.9

10.6

3.1

11.8

One point COP improvement represents 3% annual heating cost What are the Actual Entering Water Temperatures?

Geothermal System EWT – Winter GeoEx_LWST

50

GeoEx_LWRT

OA_Temp

Supply Temp

40.0 Deg F

45 40 35

Temperature - Deg F

Return Temp

34.6 Deg F

30 25 20 Outside Air Temp 15 10 5 0 -5 -10 -15 Sunday, January 25, 2004

Monday, January 26, 2004

Tuesday, January 27, 2004

Wednesday, January 28, 2004

Thursday, January 29, 2004

Friday, January 30, 2004

Saturday, January 31, 2004

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Energy Considerations „



Circulating Pump Energy ●

Pumping Energy Can Be Significant due to 24 / 7 Load Factor



Minimizing Pump Head effective



Many Geothermal Systems have excess Pumping Energy



Circulating Pump Monitored Energy Use: −

Represents 8 % of the HVAC Metered Peak Demand



Consumes 36 % of the Total Building HVAC Energy



Responsible for 18 % of the Total Building Energy Costs

Evaluate Pumping Options ●

Decentralized Loop Distribution



Two stage parallel pumping



Variable Flow pumping w/VFD’s

Operation and Maintenance Pros and Cons

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Geothermal System Features „ Operation and Maintenance Pros + Unitary equipment – failure of one unit + Simple, not complex – Reduces Service Contracts + Avoids Boiler, Condensing Units or Cooling Towers + Elaborate Control Systems not required + No annual Boiler Teardown and Inspections

Geothermal System Features „ Operation and Maintenance Cons − Quantity of units to maintain − Heat pump locations accessible − Air filters and drain pans (unitary)

„ O & M Considerations = Refrigerant 22 vs 410A = Equipment/compressor service life of 19 years = Looping piping service life of 50 + years

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Environmental Pros and Cons

Geothermal System Features „ Environmental Pros + More comfortable indoor environment > Each unit operates independently, allowing either heating or cooling to occur as required > Individual Room Control

+ No make up water for Boiler / Cooling Tower + No Chemical Treatment / Hazardous Materials + Eliminate Carbon Monoxide (CO) Potential + No Vandalism or Security Concerns + Minimal floor area required + Less energy means less natural resources and less pollution

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Geothermal System Features „ Environmental Cons − Noise inside building

„ Environmental Considerations = Selection of circulating fluids = Temporary disturbance of landscaping = Design for proper indoor air quality

Where does a Geothermal System Apply?

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Geothermal Applications „ New Construction ● Integrate GeoExchange into design ● Optimize system efficiency and costs

„ Retrofit Construction ● Air condition existing non A/C building ● Replace Unit Ventilators or Fan Coil Units ● Minimum disturbance for Historical Preservation

Geothermal Applications „ Building Type ● Good application: + Single-story – finger plan + Balanced envelope / interior thermal loads

● Weak application: − New well insulated multi-story “box” with high internal loads

● Residential + Excellent application

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Geothermal Applications „ Schools are Good Candidates for Geothermal Heat Pump Systems 9 Retrofit older systems 9 Air conditioning upgrade 9 School building layout normally good for balanced heating/cooling loads 9 Typical classroom good economic size for heat pump 9 Open field area available for Geothermal Heat Exchanger 9 System advantages attractive to schools 9 Schools will be around to enjoy the life cycle cost benefits

Geothermal Applications „ Domestic Water Heating Options ● Cooling Season = Free water heating ● Heating Season = High COP water heating

„ Desuperheater Option ● Uses 10 – 15% of Capacity to heat water ● Only works when Heat Pump in operation ● Unable to satisfy all hot water requirements

„ Switchover or Demand Option ● Uses full Capacity to heat water ● Switches from space to water heating ● Can satisfy all hot water requirements

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Geothermal Applications „ Water to Water Heat Pump Applications ● Able to heat water to 120°F ● Dedicated Domestic Water heating ● Hydronic systems ● Radiant floor systems ● Heating water/chilled water source for Outside Air/ Ventilation Air with conventional air handling systems ● Swimming Pool water heating

Radiant Floor Heating Application „ Radiant Floor ● Circulate heated water through piping circuits embedded in floor slab ● Warm Floor radiates heat to the walls, ceiling and other objects ● Water to Water Heat Pumps provide water at an effective temperature

Photo by Jeff Benz

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Geothermal System Economics $ First Costs + Energy Costs + Maintenance Costs = Bottom Line

What is the Iowa Experience?

First Cost Basics - Residential „ Heating/Cooling Delivery System ●

No significant difference in the traditional ductwork system



Installed ductwork costs are similar

„ Heat Pump ●

Compare to premium efficiency Furnace and Outside Condensing Unit – Tradeoffs



Installed unit cost premium of about $2,500 compared to a premium furnace & A/C in a typical new home (4 ton capacity)

„ Ground Heat Exchanger ●

Dependent on the soil type and system capacity



~ $1,400 to $1,600 per ton for simple residential



Gross cost of about $6,000 for 4 ton system



Credit Utility Rebates -- $0 to $2,400



Tax Credit = 30% of qualified expenditures

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First Cost Basics - Commercial „ Commercial Building Costs ● Building and HVAC System Criteria drive First Costs ● Generally, the cost inside the building is comparable ● Incremental Cost of Geothermal Heat Exchanger vs cost of Boiler, Chiller, Cooling Tower, Condensing Units, etc.

„ Manage the Installed Cost ● Reduce the total Heating / Cooling Load − Efficient Building Envelope − Efficient Lighting System − Outside Air Loads: CO2 / DCV and Energy Recovery Units

● Right Size the Heating/Cooling Equipment ● First Cost is greatly influenced by Effective Design

First Costs – Bore Field „ Summary Unit Gross Costs Gross Bore Field Cost

Range

Average

$4.50 - $7.00 / SqFt

$ 5.40 / SqFt

Cost per Ton:

$1,200 - $3,500 / Ton

$ 2,430 / Ton

Cost per Bore:

$1,500 - $4,200 / Bore

$ 2,950 / Bore

$ 8.00 - $16.00 / BoreFt

$ 13.00 / BoreFt

Cost per Square Foot:

Cost per Foot of Bore:

These are project reported bore field gross construction costs ● ● ● ● ●

The costs are not qualified for scope or normalized for conditions Costs do not include Credits for Boilers, Chillers, Cooling Towers Costs do not include Utility Company Incentives Recent Average cost cover last 3 years and include several long horizontal bore projects Additional Project Cost Information appreciated

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First Costs – Bore Field „ Typical Bore Field Costs breakdown: ● Bore hole drill rig and labor:

$6.00 -- $10.00 / bore foot

− Soil type, Field conditions

● Prefab U-bend pipe:

$0.70 -- $2.00 / bore foot

− Pipe size and thickness

● Grout and sand materials:

$0.65 -- $1.25 / bore foot

− Bore hole size and Grout type

● Total for bore hole installed:

$7.35 -- $13.25 / bore foot

● Multiplier for header system manifold, vault, flush, fill, test, etc: ● Total system cost:

10% to 30%

$ 8.10 -- $ 14.60 / bore foot

● Average cost:

~ $ 13.00 / bore foot

First Cost Considerations „ Recognize All System Related Cost Savings ● Boiler Stacks and Roof Penetrations ● Boiler Room Combustion Air ● Chemical Treatment, Make Up Water and related equipment ● Structural Cost for Cooling Tower or Equipment Support ● Screen Walls and Fences for Vision, Vandalism, Security ● Machine Room (Refrigerant) Ventilation ● Natural Gas Service Entrance ● Reduced Mechanical Equipment Floor area

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First Cost Considerations „ Utility Company Incentives ● $ 0 to $ 600 per ton ● $100 to $150 Bonus for High Rated COP and EER ● $100 for Desuperheater Option ● Custom Incentive Programs ● Alternate Rate Schedules ● Check with the Local Utility before Design

„ Financing Options ● Iowa Energy Bank Loan ● Utility Company Financing ● Energy Savings or Performance Contracting

„ Tax Incentives ● Residential: Personal Tax Credit of 30% of qualified expenditures ● Business: Corporate Tax Credit of 10% of expenditures ● Commercial: Up to $1.80 per SF for 50% better than Energy Standard

Energy Costs

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Energy Costs „ All Electric / Electric Heat Rate Schedule ● Most Significant Factor for Energy Costs ● Identify the applicable Rate Schedule ● Electric Costs of 4 ¢/KWH vs. 8 ¢/KWH for winter usage ● Some Rates may be applied to the total building electrical usage

„ Electrical Demand – Commercial Buildings ● Typical Reduction in Electrical Demand ● Demand Limiting / Load Shedding Opportunities ● Demand may be a significant factor in total electric costs

Heating Energy Equivalents Energy Source Fuel Type

Energy

Energy

Energy

Heating

Net Heating

Unit

Unit Cost

Content

Equipment Efficiency

Energy Cost $/Million BTU

Typical Application

Predicted Cost for Example Residence Heating $ per Year

$ per Unit

BTU per Unit

Natural Gas

Therm Therm

$1.17 $1.17

100,000 100,000

92% AFUE Furnace 75% AFUE Furnace

$ $

12.72 15.60

New Hi Eff Natural Gas Furnace Older Natural Gas Furnace

$ $

1,314 1,612

Propane

Gallon Gallon

$2.21 $2.21

91,600 91,600

92% AFUE Furnace 70% AFUE Furnace

$ $

26.22 34.47

New Hi Eff Propane Furnace Older Propane Furnace

$ $

2,710 3,562

Fuel Oil

Gallon Gallon

$2.65 $2.65

139,000 139,000

85% AFUE Furnace 65% AFUE Furnace

$ $

22.43 29.33

New Fuel Oil Furnace Older Fuel Oil Furnace

$ $

2,318 3,031

Electricity Higher Rate

KWH KWH KWH

$0.10 $0.10 $0.10

3,412 3,412 3,412

1.0 8.0 3.6

COP Resistance HSPF Heat Pump COP Geo Heat Pump

$ $ $

29.31 12.50 8.14

Baseboard Resistance Heat Air Source Heat Pump Hi Eff Geothermal Heat Pump

$ $ $

3,029 1,292 841

Electricity Lower Rate

KWH KWH KWH

$0.05 $0.05 $0.05

3,412 3,412 3,412

1.0 8.0 3.6

COP Resistance HSPF Heat Pump COP Geo Heat Pump

$ $ $

14.65 6.25 4.07

Resistance Heat Air Source Heat Pump Hi Eff Geothermal Heat Pump

$ $ $

1,515 646 421

Shelled Corn

Bushel

$3.89

392,000

75% Hi Eff Corn Furnace

$

13.23

HiEff Corn Furnace (15% Moisture)

$

1,367

Wood Hardwood Air Dried

Cord Cord Cord

$125.00 $125.00 $125.00

20,000,000 20,000,000 20,000,000

20% Standard Fireplace 40% Franklin Wood Stove 70% Hi Eff Wood Furnace

$ $ $

31.25 15.63 8.93

Tight Packed Cord (4'Hx2'Dx16'L) Hardwood Dried @ 8,500 BTU/lb Annualized Efficiency Considered

$ $ $

3,230 1,615 923

Example Residence: Design Heat Loss of Building:

53,000 BTU per Hour

Annual Heating Degree Days:

6,500 HDD per year

Annual Heating Energy Req'd:

103.4

Calculated from Area and R-Values of walls, roof, windows, etc. - 53,000 BTU/Hr is average new Iowa home (1760 SF). Weather Data representing the "coldness" of the winter season - 6,500 HDD is an averge HDD value for Central Iowa.

Million BTU per Year with an predicted cost of

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Energy Costs

„ Case Studies – Ankeny Elementary Schools ● Actual Site Energy Reduction:

46% to 54% BTU/SF-Yr

● Actual Energy Cost Reduction:

6% to 14% $/SF-Yr

Non Air Conditioned to Air Conditioned

● Energy Cost Avoidance:

20% to 34% $/SF-Yr

Site Energy Use Index – Ankeny Schools 100,000

83,187 BTU/SF-yr

90,000

Average Conventional System

Site EUI, BTU / sq. ft. yr.

80,000

70,000

60,000

42% Reduction 48,468 BTU/SF-yr Average Geothermal System

50,000

40,000

30,000

20,000

10,000

0 Southeast

Crocker

East

Northwest

Terrace

Westwood Northeast Parkview Northview

Ankeny High

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Energy Cost Index – Ankeny Schools 140.00

112.7 ¢ /SF-yr Avg Conventional System

Energy Cost Index, ¢ / sq. ft. yr.

120.00

100.00

45% reduction 80.00

62.2 ¢ /SF-yr Avg. Geothermal System

60.00

40.00

20.00

0.00 Southeast

Crocker

East

Northwest

Terrace

Northeast

Westwood

Parkview

Northview

Ankeny High

Geothermal Heat Pumps From a Residential Perspective What are the Energy Efficiency Alternatives ?

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Average Iowa Home „ 1760 Square Feet + Lower Level „ Heating Equipment Capacity: ● Winter Heat Loss of 53,000 BTU/Hr ● 70 °F inside / -10 °F outside ● Central Iowa – 6500 Heating Degree Days

„ Cooling Equipment Capacity ● Summer Heat Gain of 21,300 BTU/Hr ● 75 °F inside / 95 °F outside ● Central Iowa – 1100 Cooling Degree Days

Installation Options „ Low Efficiency ● 80 % Natural Gas Furnace ● 80,000 BTUH Input / 64,000 BTUH Output ● 2 ton – 11 SEER Central Air Conditioner

„ High Efficiency ● 92 % Natural Gas Furnace ● 60,000 BTUH Input / 55,200 BTUH Output ● 2 ton – 13 SEER Central Air Conditioner

„ Geothermal Heat Pump System ● 4 Ton Geo Heat Pump – 4.0 COP w/ 5 KW auxiliary heat ● 41,000 BTUH Input / 58,000 BTUH Output w/ aux heat ● 4 ton cooling at 18.0 EER

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HVAC System Costs HVAC System Cost Base HVAC Equipment: 53 MBH / 24 MBH Base Equipment Cost Ductwork, Accessories & Installation Geothermal Heat Exchanger and Circ Pump or Gas line, Flues Vents, Refrig Lines Options: Energy Recovery Ventilation Humidifier, Premium Filter, Exhaust Fans Total Amount

Low Efficiency Gas / Cent Air

High Efficiency Gas / Cent Air

Geothermal Heat Pump

66 MBH/2 Ton $ 2,500 6,000 1,200

60 MBH/2 Ton $ 3,500 6,000 1,200

4 Ton Heat/2 Ton $ 6,000 6,000 7,000

2,000 1,200 $ 12,900

2,000 1,200 $ 13,900

2,000 1,200 $ 22,200

Utilty Company Rebates Net HVAC System Installed Cost Percent Increase

0

250

2,100

$ 12,900

$ 13,650

$ 20,100

6%

47%

OR Existing Retrofit

Above does not include Tax Credit of 30% or about $6,000

Energy Use and Cost Energy

Low Efficiency Gas / Cent Air

High Efficiency Gas / Cent Air

Geothermal Heat Pump

$1.25 $0.06 $0.09

per Therm per KWH per KWH

Base Energy KWH 1,000 $0.09

Natural Gas - Winter Heating Electric Rate - Winter Heating Electric Rate - Summer Cooling Heating AFUE/COP Cooling SEER/EER $ / Million BTU Base Energy - First KWH = Annual Heating Cost Annual Cooling Cost Total Annual Cost Average Monthly Cost

80% 11.0 $15.63 1,000

$

$

1,080 1,612 230 2,922 $243.49

92% 12.0 $13.59 $

$

1,080 1,402 211 2,692 $224.37

3.6 18.0 $4.88 $

1,080 504 141 1,724

$

$143.71

Electric Heating Rate of 6¢ per KWH on use over 1,000 KWH/Mo

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Total Monthly Cost – PITI + Energy Acquisition

Low Efficiency Gas / Cent Air

High Efficiency Gas / Cent Air

Geothermal Heat Pump

$ 220,000 $ 12,900 $ 232,900 $ 25,000 $ 207,900

$ 220,000 $ 13,650 $ 233,650 $ 25,000 $ 208,650

$ 220,000 $ 20,100 $ 240,100 $ 25,000 $ 215,100

6.40% 360

6.40% 360

6.40% 360

Principal and Interest Taxes Insurance Energy

$ 1,300.43 $ 200.00 $ 50.00 $ 243.49

$ 1,305.12 $ 200.00 $ 50.00 $ 224.37

$ 1,345.46 $ 200.00 $ 50.00 $ 143.71

Total Monthly Payment

$ 1,793.91

$ 1,779.49

$ 1,739.17

Monthly Energy Penalty

$

$

$

Base Construction @ $ / SF = $125 Net HVAC System Installed Cost Purchase Price Down Payment Loan Amount Monthy Payment Annual Interest Rate %/yr Term in Months

(54.74)

(40.32)

-

Economic Performance „ Bottom Line ● Most Energy Efficient Heating & Cooling System Available ● Comfortable with a High Degree of Owner Satisfaction ● Reduces Energy Cost by 20% to 35% ● Adds 2 – 4% to the Total Cost of New Construction ● Incentives, Credits and Alternate Financing may be Available ● Typical 5 to 12 year payback ● Generally Best Life Cycle Costs ● Considering PITI & Energy…… $40 to $50 monthly Cost Penalty to use Conventional System

„ Each Commercial / Residential Facility is Unique

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May 6 – 8, 2009

Introduction to Geothermal Heat Pump Systems Thank You…….. Discussion ! ! ! ! Questions ???? Energy Resource Station at DMACC Phone: 515-965-7055 [email protected] www.energy.iastate.edu

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