GROUND SOURCE HEAT PUMPS An Overview PRESENTERS: CHAD MARTIN , PE, - - PDF document

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GROUND SOURCE HEAT PUMPS An Overview PRESENTERS: CHAD MARTIN , PE, - - PDF document

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GROUND SOURCE HEAT PUMPS An Overview PRESENTERS: CHAD MARTIN , PE, / EASTERN REGIONAL MANAGER / GEOTHERMAL RESOURCE TECHNOLOGIES CHRIS EDMONDSON / CEO / JAMES M. PLEASANTS COMPANY ADAM SPACH , PE, LEED AP / ASSOCIATE / STANFORD WHITE BILL

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GROUND SOURCE HEAT PUMPS An Overview

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PRESENTERS: CHAD MARTIN, PE, / EASTERN REGIONAL MANAGER / GEOTHERMAL RESOURCE TECHNOLOGIES CHRIS EDMONDSON / CEO / JAMES M. PLEASANTS COMPANY ADAM SPACH, PE, LEED AP / ASSOCIATE / STANFORD WHITE BILL SMITH BILL SMITH, PE, LEED AP / PRINCIPAL / STANFORD WHITE

Ground Source Heat Pumps – An Overview SCO Conference: March 24, 2011

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INTRODUCTION OVERVIEW The basics

  • The basics
  • Is the project site geothermal friendly ?

Is the project site geothermal friendly ?

  • System equipment

y q p

  • Is ground source a good choice for you ?

Ground Source Heat Pumps – An Overview SCO Conference: March 24, 2011

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SLIDE 4

THE BASICS

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THE BASICS DEFINITION Geothermal Heat Pump Geothermal Heat Pump

  • Electrically powered system that takes advantage of

the earth's relatively constant temperature to provide y p p building heating and cooling.

Ground Source Heat Pumps – An Overview SCO Conference: March 24, 2011

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THE BASICS PROCESS Heat Pump Refrigeration Cycle Heat Pump Refrigeration Cycle

  • Air-to-Air

Ground Source Heat Pumps – An Overview SCO Conference: March 24, 2011

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THE BASICS PROCESS Heat Pump Refrigeration Cycle

Cooling Tower

Heat Pump Refrigeration Cycle

  • Water-to-Air

Cooling Tower Boiler

Ground Source Heat Pumps – An Overview SCO Conference: March 24, 2011

Boiler

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THE BASICS PROCESS Heat Pump Refrigeration Cycle Heat Pump Refrigeration Cycle

  • Geothermal: replace water-side

cooling tower and boiler with g earth coupled system

Ground Source Heat Pumps – An Overview SCO Conference: March 24, 2011

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THE BASICS HOW DOES IT WORK ? Ground Water Temperatures Ground Water Temperatures

Ground Source Heat Pumps – An Overview SCO Conference: March 24, 2011

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THE BASICS HOW DOES IT WORK ? The earth is a source of heat in the winter The earth is a source of heat in the winter

Outdoor air design temperature: 15°F 72°F 62°F Geothermal heat pumps transfer underground heat into buildings to provide heating

Ground Source Heat Pumps – An Overview SCO Conference: March 24, 2011

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THE BASICS HOW DOES IT WORK ? The earth is an efficient way to reject heat in the summer The earth is an efficient way to reject heat in the summer

Outdoor air design temperature: design temperature: 95°F 74°F 62°F Geothermal heat pumps transfer heat from

Ground Source Heat Pumps – An Overview SCO Conference: March 24, 2011

p p buildings into the ground to provide cooling

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THE BASICS HOW DOES IT WORK ? Using water source heat pumps with the earth Using water source heat pumps with the earth Geothermal heat pumps circulate water through a earth coupled water through a earth coupled system where it is naturally warmed (or cooled) by the Earth

Ground Source Heat Pumps – An Overview SCO Conference: March 24, 2011

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THE BASICS TYPES OF GEOTHERMAL HEAT PUMP SYSTEMS Ground Source Heat Pump GSHP Ground Source Heat Pump GSHP Ground Water Heat Pump GWHP Surface Water Heat Pump SWHP Open Loop Closed Loop Ground Coupled Heat Pump GCHP Ground Coupled Heat Pump GCHP Horizontal

Ground Source Heat Pumps – An Overview SCO Conference: March 24, 2011

Vertical

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THE BASICS TYPES OF GEOTHERMAL HEAT PUMP SYSTEMS Ground Source Heat Pump GSHP Ground Source Heat Pump GSHP Ground Water Heat Pump GWHP Surface Water Heat Pump SWHP Open Loop Closed Loop Ground Coupled Heat Pump GCHP Ground Coupled Heat Pump GCHP Horizontal

Ground Source Heat Pumps – An Overview SCO Conference: March 24, 2011

Vertical

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THE BASICS TYPES OF GEOTHERMAL HEAT PUMP SYSTEMS Ground Source Heat Pump GSHP Ground Source Heat Pump GSHP Ground Water Heat Pump GWHP Surface Water Heat Pump SWHP Open Loop Closed Loop Ground Coupled Heat Pump GCHP Ground Coupled Heat Pump GCHP Horizontal

Ground Source Heat Pumps – An Overview SCO Conference: March 24, 2011

Vertical

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THE BASICS TYPES OF GEOTHERMAL HEAT PUMP SYSTEMS Ground Source Heat Pump GSHP Ground Source Heat Pump GSHP Ground Water Heat Pump GWHP Surface Water Heat Pump SWHP Open Loop Closed Loop Ground Coupled Heat Pump GCHP Ground Coupled Heat Pump GCHP Horizontal

Ground Source Heat Pumps – An Overview SCO Conference: March 24, 2011

Vertical

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THE BASICS TYPES OF GEOTHERMAL HEAT PUMP SYSTEMS Ground Source Heat Pump GSHP Ground Source Heat Pump GSHP Ground Water Heat Pump GWHP Surface Water Heat Pump SWHP Open Loop Closed Loop Ground Coupled Heat Pump GCHP Ground Coupled Heat Pump GCHP Horizontal

Ground Source Heat Pumps – An Overview SCO Conference: March 24, 2011

Vertical

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THE BASICS TYPES OF GEOTHERMAL HEAT PUMP SYSTEMS Ground Source Heat Pump GSHP Ground Source Heat Pump GSHP Ground Water Heat Pump GWHP Surface Water Heat Pump SWHP Open Loop Closed Loop Ground Coupled Heat Pump GCHP Ground Coupled Heat Pump GCHP Horizontal

Ground Source Heat Pumps – An Overview SCO Conference: March 24, 2011

Vertical

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THE BASICS TYPES OF GEOTHERMAL HEAT PUMP SYSTEMS

  • The focus of today’s presentation is:

The focus of today s presentation is: Vertical Ground Coupled Heat Pump

Ground Source Heat Pumps – An Overview SCO Conference: March 24, 2011

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IS THE PROJECT SITE GEOTHERMAL FRIENDLY? GEOTHERMAL FRIENDLY?

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IS THE PROJECT SITE GEOTHERMAL FRIENDLY ? GETTING STARTED Geothermal Testing Agency Geothermal Testing Agency

  • Check credentials and standards
  • 2007 ASHRAE Applications Handbook,

pages 32.12-32.13

  • IGSHPA “Closed-Loop/Geothermal

Heat Pump Systems - Design & Installation Standards 2009 Edition”

Ground Source Heat Pumps – An Overview SCO Conference: March 24, 2011

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IS THE PROJECT SITE GEOTHERMAL FRIENDLY ? GETTING STARTED Geothermal Testing Agency Geothermal Testing Agency

  • Ensure testing agency dialogue with MEP firm
  • Establish preliminary building loads

(e.g. 350 sq ft/ton)

  • Set target bore depth

(should be same as design depth)

Ground Source Heat Pumps – An Overview SCO Conference: March 24, 2011

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IS THE PROJECT SITE GEOTHERMAL FRIENDLY ? GETTING STARTED Geothermal Testing Agency Geothermal Testing Agency

  • Work with owner to determine test bore locations
  • Test bore quantity dependent upon site topography,

loopfield size, drilling conditions, etc.

  • Variations in topography (depth to bedrock) may

vary testing needs to properly characterize site.

Ground Source Heat Pumps – An Overview SCO Conference: March 24, 2011

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IS THE PROJECT SITE GEOTHERMAL FRIENDLY ? DRILLING Test Bores Test Bores

  • Hire geothermal-based drilling company

(IGSHPA directory, local drillers) ( y )

  • Must be certified by NC Well Contractor

Certification Commission

  • Testing agency/MEP firm will specify test

bore details (depth, u-bend size, grout mix)

Ground Source Heat Pumps – An Overview SCO Conference: March 24, 2011

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IS THE PROJECT SITE GEOTHERMAL FRIENDLY ? DRILLING Test Bores Test Bores

  • Drilling process varies

according to geology g g gy

  • Mud-rotary typical for

unconsolidated formations (east of I-95)

  • Air-rotary typical for

k f ti rock formations (west of I-95)

Ground Source Heat Pumps – An Overview SCO Conference: March 24, 2011

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IS THE PROJECT SITE GEOTHERMAL FRIENDLY ? DRILLING Test Bores (Pre-test considerations) Test Bores (Pre test considerations)

  • Permitting varies for well types:
  • Type 5QW - Closed-Loop Geothermal-Water-Only Injection Well System

This type only requires “Notification of Intent to Construct” form sent to state.

  • Type 5QM - Closed-Loop Geothermal-Mixed-Fluid Injection Well System

This type requires permit. Regional office of Dept. of Water Quality will d t it i ti U i b t ff it i t d conduct pre-permit inspection. Upon review by staff, permit is granted.

Ground Source Heat Pumps – An Overview SCO Conference: March 24, 2011

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IS THE PROJECT SITE GEOTHERMAL FRIENDLY ? DRILLING Test Bores (Pre-test considerations) Test Bores (Pre test considerations)

  • Start this process early

(permits, drilling, rest period, (p g p test period, reporting)

  • Site conditions: accessibility for drill

rig, power source, noise restrictions, adjacent construction

Ground Source Heat Pumps – An Overview SCO Conference: March 24, 2011

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IS THE PROJECT SITE GEOTHERMAL FRIENDLY ? TESTING Formation Thermal Conductivity (FTC) Test Formation Thermal Conductivity (FTC) Test

  • “A field test to determine the AVERAGE thermal

conductivity of the formation throughout the entire y g length of the vertical bore.”

  • Also known as In-Situ Testing

100 105 31 00 31.50

Loop In Temp 10-45.4 hr Average Loop Out Temp Heat Rate

85 90 95 100 erature (F) 29.50 30.00 30.50 31.00

  • usands)

Rate (Btu/hr) 65 70 75 80 Tempe 27.50 28.00 28.50 29.00 (Tho Heating R

Ground Source Heat Pumps – An Overview SCO Conference: March 24, 2011

6 12 18 24 30 36 42 48 Time (hours) 60 27.00

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IS THE PROJECT SITE GEOTHERMAL FRIENDLY ? TESTING Reasons Reasons

  • Designing ground loop requires accurate knowledge of

formation thermal properties p p

  • Prevents over/under sizing of loop. Buildings with undersized

loops result in heat pumps with reduced capacity and lower efficiencies during peak loads. Oversized loops have larger upfront cost with minimal efficiency benefit. I t t k l d f b il diti

  • Improves contractor knowledge of subsoil conditions

(depth to bedrock, water production, mud seams, voids, etc.)

  • Helps reduce uncertainties ($) in bid process
  • Helps reduce uncertainties ($) in bid process

Ground Source Heat Pumps – An Overview SCO Conference: March 24, 2011

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IS THE PROJECT SITE GEOTHERMAL FRIENDLY ? TESTING Results Results

  • Formation Thermal Conductivity - ability of formation

to transport heat p

  • Thermal Diffusivity – ratio of heat transport ability to

heat storage capacity. Materials with high diffusivity rapidly change temperature to match surroundings

  • Undisturbed Formation Temperature – average

t t f f ti ith d th temperature of formation with depth.

Ground Source Heat Pumps – An Overview SCO Conference: March 24, 2011

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IS THE PROJECT SITE GEOTHERMAL FRIENDLY ? TESTING Test Rig Schematic Test Rig Schematic

Ground Source Heat Pumps – An Overview SCO Conference: March 24, 2011

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IS THE PROJECT SITE GEOTHERMAL FRIENDLY ? TESTING Test Unit Test Unit

Ground Source Heat Pumps – An Overview SCO Conference: March 24, 2011

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IS THE PROJECT SITE GEOTHERMAL FRIENDLY ? TESTING Test Setup Test Setup

Ground Source Heat Pumps – An Overview SCO Conference: March 24, 2011

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IS THE PROJECT SITE GEOTHERMAL FRIENDLY ? TESTING Example Drill Logs Example Drill Logs

Raleigh, NC (Highway Patrol Training Center)

Note: PVC casing was installed from 0-108 ft and removed at bore completion. D ill L R d l 0' 15' Drill Log .................... Red clay 0'-15' Soft silty dirt 15'-80' Fractured white rock with some clay seams 80'-105' Rock (gneiss) 105'-350' Note: The bore produced approx. 1-2 gpm water.

Elizabeth City, NC (State University Building)

Drill Log .................... Sand / Silt mix 0'-30' Silt / Shell rock 30' 80' Silt / Shell rock 30'-80' Shell rock 80'-95' Clayey silt 95'-300'

Ground Source Heat Pumps – An Overview SCO Conference: March 24, 2011

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IS THE PROJECT SITE GEOTHERMAL FRIENDLY ? TESTING Example Test Data/Results Example Test Data/Results

NC Highway Patrol Training Academy February 7-9, 2011 NC Highway Patrol Training Academy February 7-9, 2011

90 95 100 105 ) 30 00 30.50 31.00 31.50 /hr)

Loop In Temp 10-45.4 hr Average Loop Out Temp Heat Rate

90 95 100 105 ) 30 00 30.50 31.00 31.50 /hr)

Loop In Temp 10-45.4 hr Average Loop Out Temp Heat Rate

70 75 80 85 90 Temperature (F 28.00 28.50 29.00 29.50 30.00 (Thousands) Heating Rate (Btu/ 70 75 80 85 90 Temperature (F 28.00 28.50 29.00 29.50 30.00 (Thousands) Heating Rate (Btu/ 6 12 18 24 30 36 42 48 Time (hours) 60 65 27.00 27.50

  • 1

1 2 3 4 ln(Time) 60 65 27.00 27.50

Ground Source Heat Pumps – An Overview SCO Conference: March 24, 2011

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IS THE PROJECT SITE GEOTHERMAL FRIENDLY ? TESTING Example Test Data/Results Example Test Data/Results

Asheville Charlotte Raleigh Elizabeth City Formation Thermal Conductivity (Btu/hr‐ft‐◦F) 2.03 1.25 1.34 1.04 y ( ) Formation Thermal Diffusivity (ft2/day) 1.39 0.84 0.88 0.71 Undisturbed Formation Temperature (◦F) 58.3‐59 61‐61.4 62 63‐63.5

Ground Source Heat Pumps – An Overview SCO Conference: March 24, 2011

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IS THE PROJECT SITE GEOTHERMAL FRIENDLY ? APPLICATION Parameters for Well Field Layout Parameters for Well Field Layout

  • Well depth (refer to test, what is most efficient)
  • Total number of bores required
  • Grout thermal conductivity
  • Spacing between bores

(20’ rule, ground water temp effect, d illi th h dj t b ) drilling through adjacent bores)

  • Piping sizes

Ground Source Heat Pumps – An Overview SCO Conference: March 24, 2011

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IS THE PROJECT SITE GEOTHERMAL FRIENDLY ? APPLICATION Well Grouting Well Grouting

  • First Priority: must abide by State regulations

(NC Division of Water Quality, UIC Program) ( y g )

  • Bores should be grouted with tremie pipe from

bottom to top

  • Grout thermal conductivity and should be
  • ptimized with respect to performance and

i economics.

Ground Source Heat Pumps – An Overview SCO Conference: March 24, 2011

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IS THE PROJECT SITE GEOTHERMAL FRIENDLY ? APPLICATION Well Field Piping Well Field Piping

  • High density polyethylene (HDPE)
  • Heat fused – pipes are melted together
  • 50 year warranty

U-Bend Pipe Diameter Completed Bore Depth 3/4 inch 100 - 200 ft 1 inch 150 300 ft 1 inch 150 - 300 ft 1-1/4 inch 250 - 500 ft

Heat Fusing

Ground Source Heat Pumps – An Overview SCO Conference: March 24, 2011

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IS THE PROJECT SITE GEOTHERMAL FRIENDLY ? APPLICATION Well Field Layout (examples) Well Field Layout (examples)

  • Multiple Unitary Loops

Ground Source Heat Pumps – An Overview SCO Conference: March 24, 2011

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IS THE PROJECT SITE GEOTHERMAL FRIENDLY ? APPLICATION Well Field Layout (examples) Well Field Layout (examples)

  • Multiple Sub-Central Loops

Ground Source Heat Pumps – An Overview SCO Conference: March 24, 2011

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IS THE PROJECT SITE GEOTHERMAL FRIENDLY ? APPLICATION Well Field Layout (examples) Well Field Layout (examples)

  • Central Loop

Ground Source Heat Pumps – An Overview SCO Conference: March 24, 2011

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IS THE PROJECT SITE GEOTHERMAL FRIENDLY ? APPLICATION Well Field Installation Well Field Installation

  • Using socket fusion to

connect vertical loops p to header piping

Ground Source Heat Pumps – An Overview SCO Conference: March 24, 2011

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IS THE PROJECT SITE GEOTHERMAL FRIENDLY ? APPLICATION Well Field Installation Well Field Installation

  • Using socket fusion to

connect vertical loops p to header piping

Ground Source Heat Pumps – An Overview SCO Conference: March 24, 2011

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SYSTEM EQUIPMENT

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SYSTEM EQUIPMENT WATER SOURCE HEAT PUMPS How Do They Operate? How Do They Operate?

Air Out 58 F Water Out 95 F Water In 85 F

Exchange Heat Between

95 F 85 F Fan Air Coil

Heats or Cools on Demand

Air and Water

Water Coil Air Coil Expansion Valv e

Operates on the Same Principle as a Refrigerator

C Rev ersing Valv e

(Cooling Shown)

Ground Source Heat Pumps – An Overview SCO Conference: March 24, 2011

Air In 80 F Compressor

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SYSTEM EQUIPMENT WATER SOURCE HEAT PUMPS How Do They Operate?

Moves Heat Efficiently !

How Do They Operate?

$1 Worth of Electricity to Operate the Compressor and

y

Air Out 100 F Water Out 54 F Water In 60 F

$5 $5 $4 $4

p p Fan Moves $4 Worth of Heat from the Water (from other heat

54 F 60 F Fan Ai C il

$4 $4

( pumps; only in few hours from boiler in Southeast Region; “free” from geo. field)

Water Coil Air Coil Expansion Valv e

) Delivering $5 Worth of Heat into the Air

Rev ersing Valv e

$1 $1

Ground Source Heat Pumps – An Overview SCO Conference: March 24, 2011

(Heating Shown)

Air In 70 F Compressor

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SYSTEM EQUIPMENT WATER SOURCE HEAT PUMPS Common Equipment Types Common Equipment Types

  • Horizontal

½ - 10 tons

  • Vertical

¾ - 25 tons

  • Console

½ - 1 ½ tons

  • Vertical Stacked

¾ - 3 tons

  • Roof Mounted

3 - 20 tons

Ground Source Heat Pumps – An Overview SCO Conference: March 24, 2011

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SYSTEM EQUIPMENT WATER SOURCE HEAT PUMPS Horizontal Horizontal

  • 1/2 - 10 tons
  • Typically exposed or above ceilings

Ground Source Heat Pumps – An Overview SCO Conference: March 24, 2011

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SYSTEM EQUIPMENT WATER SOURCE HEAT PUMPS Horizontal Horizontal

Ground Source Heat Pumps – An Overview SCO Conference: March 24, 2011

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SYSTEM EQUIPMENT WATER SOURCE HEAT PUMPS Vertical Vertical

  • 3/4 - 25 tons
  • Typically in mechanical

rooms or closets

Ground Source Heat Pumps – An Overview SCO Conference: March 24, 2011

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SYSTEM EQUIPMENT WATER SOURCE HEAT PUMPS Vertical Vertical

Ground Source Heat Pumps – An Overview SCO Conference: March 24, 2011

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SYSTEM EQUIPMENT WATER SOURCE HEAT PUMPS Vertical Vertical

Ground Source Heat Pumps – An Overview SCO Conference: March 24, 2011

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SYSTEM EQUIPMENT WATER SOURCE HEAT PUMPS Console Console

  • ½ - 1 ½ tons
  • Low profile, finished cabinet

make consoles excellent for: Dorm rooms Offices Corridors St i ll Stairwells

Ground Source Heat Pumps – An Overview SCO Conference: March 24, 2011

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SYSTEM EQUIPMENT WATER SOURCE HEAT PUMPS Vertical Stacked Vertical Stacked

  • ¾ - 3 tons
  • Versatile unit
  • Built-into wall
  • Built-into wall

Ground Source Heat Pumps – An Overview SCO Conference: March 24, 2011

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SYSTEM EQUIPMENT WATER SOURCE HEAT PUMPS Vertical Stacked Vertical Stacked

Ground Source Heat Pumps – An Overview SCO Conference: March 24, 2011

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SYSTEM EQUIPMENT WATER SOURCE HEAT PUMPS Vertical Stacked Vertical Stacked

Ground Source Heat Pumps – An Overview SCO Conference: March 24, 2011

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SYSTEM EQUIPMENT WATER SOURCE HEAT PUMPS Vertical Stacked Vertical Stacked

  • Very maintenance

friendly

Ground Source Heat Pumps – An Overview SCO Conference: March 24, 2011

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SYSTEM EQUIPMENT WATER SOURCE HEAT PUMPS Roof Mounted Roof Mounted

  • 3 - 20 tons

Ground Source Heat Pumps – An Overview SCO Conference: March 24, 2011

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SYSTEM EQUIPMENT WATER SOURCE HEAT PUMPS Equipment Ratings Equipment Ratings

  • Water side temperatures:
  • 60F – 95F for boiler/cooling tower systems
  • 20F – 120F for geothermal systems

Ground Source Heat Pumps – An Overview SCO Conference: March 24, 2011

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SYSTEM EQUIPMENT WATER SOURCE HEAT PUMPS Equipment Ratings Equipment Ratings

  • Enhanced construction for geothermal applications:

Oversized lanced fin / rifled t b f i t t i il Variable speed ECM fan motor tube refrigerant-to-air coil T t l di Large rifled tubing coaxial refrigerant-to-water heat TXV

Ground Source Heat Pumps – An Overview SCO Conference: March 24, 2011

Two-stage unloading scroll compressor refrigerant-to-water heat exchanger TXV

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SYSTEM EQUIPMENT WATER SOURCE HEAT PUMPS Equipment Ratings Equipment Ratings

  • Enhanced efficiency rating choices:
  • 12.0 EER

“Good”

  • 12.5 EER

“Better” 15 0 EER “B t”

  • 15.0 EER

“Best”

  • 20 EER*

“Better than Best”

  • 27 EER*

“Best of the Best”

  • 27 EER

Best of the Best

*GLHP EER ratings

Ground Source Heat Pumps – An Overview SCO Conference: March 24, 2011

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SYSTEM EQUIPMENT WATER SOURCE HEAT PUMPS Performance Options Performance Options

  • Reduced noise (extra compressor isolation)
  • Soft start variable speed fan
  • Integral reheat (humidity control)

D ti h t t t i t f

  • Domestic hot water system interface

Ground Source Heat Pumps – An Overview SCO Conference: March 24, 2011

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SYSTEM EQUIPMENT WATER SOURCE HEAT PUMPS Outside Air Outside Air “It is an infinitely varying load condition that is sized at peak design load and must operate at all operating conditions design load and must operate at all operating conditions above the design leaving air dewpoint.”

Ground Source Heat Pumps – An Overview SCO Conference: March 24, 2011

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SYSTEM EQUIPMENT WATER SOURCE HEAT PUMPS Outside Air Outside Air

  • PITFALL: “standard” heat pumps are not

designed to handle 100% outdoor air g

  • 3 Row Coils too light for 95/78 conditions

(compressor suction temperature way above design)

  • Generally cannot heat air below 50 - 55º

t i i t t entering air temperature

Ground Source Heat Pumps – An Overview SCO Conference: March 24, 2011

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SYSTEM EQUIPMENT WATER SOURCE HEAT PUMPS Outside Air Outside Air

  • US dew point temperatures

Ground Source Heat Pumps – An Overview SCO Conference: March 24, 2011

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SYSTEM EQUIPMENT WATER SOURCE HEAT PUMPS Dedicated 100% Outside Air Water Source Heat Pump Units Dedicated 100% Outside Air Water Source Heat Pump Units

VERTICAL UNIT

Ground Source Heat Pumps – An Overview SCO Conference: March 24, 2011

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SYSTEM EQUIPMENT WATER SOURCE HEAT PUMPS Dedicated 100% Outside Air Water Source Heat Pump Units Dedicated 100% Outside Air Water Source Heat Pump Units

Ground Source Heat Pumps – An Overview SCO Conference: March 24, 2011

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SYSTEM EQUIPMENT WATER SOURCE HEAT PUMPS Pumping Pumping

  • Affects system performance

(temperatures, flows, controllability, energy usage) ( p y gy g )

2” PE typical Heat Pump Supply Heat Pump Return Expansion CWS Pressure Reducer/Relief Backflow Preventor 3/4” Air Vent Air Separator Bypass

Geothermal Mechanical

3” Copper 125 GPM @ 70’ Pumps Primary/Standby Charging

Mechanical Room

Ground Source Heat Pumps – An Overview SCO Conference: March 24, 2011

2” PE typical Ground Loop Supply Ground Loop Return

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SYSTEM EQUIPMENT WATER SOURCE HEAT PUMPS Pumping Options Pumping Options

  • Option 1 - Redundant Alternate – Full flow pump with duplicate

redundant pump in parallel (control alternately) redundant pump in parallel (control alternately)

  • Option 2 - Redundant Staged - Two pumps in parallel to handle load

(lead lag control) (lead-lag control)

  • Option 3 - Variable speed pumps with solenoid valves at each unit
  • Option 4 - Distributed pumping - Pumps at each heat pump with single

pipe system and continuous circulation

Ground Source Heat Pumps – An Overview SCO Conference: March 24, 2011

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SYSTEM EQUIPMENT WATER SOURCE HEAT PUMPS Pumping Examples Pumping Examples

Ground Source Heat Pumps – An Overview SCO Conference: March 24, 2011

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SYSTEM EQUIPMENT WATER SOURCE HEAT PUMPS Pumping Examples Pumping Examples

Ground Source Heat Pumps – An Overview SCO Conference: March 24, 2011

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SYSTEM EQUIPMENT WATER SOURCE HEAT PUMPS Hybrid System Hybrid System

  • Very cost effective initial costs and

life cycle costs y

  • In most moderate and southern

climates, hybrid geothermal systems have a lower life cycle cost than other options R d ll fi ld i d t

  • Reduces well field size and cost

Ground Loop with Evaporative Cooling (Auxiliary Heat Rejection)

Ground Source Heat Pumps – An Overview SCO Conference: March 24, 2011

(Auxiliary Heat Rejection)

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SYSTEM EQUIPMENT WATER SOURCE HEAT PUMPS Hybrid System – Winter Operation Hybrid System Winter Operation

Heat Pump Water Pump Cooling Tower (OFF)

Ground Source Heat Pumps – An Overview SCO Conference: March 24, 2011

Earth Loops

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SYSTEM EQUIPMENT WATER SOURCE HEAT PUMPS Hybrid System – Summer Operation Hybrid System Summer Operation

Heat Pump Water Pump Cooling Tower (ON)

Ground Source Heat Pumps – An Overview SCO Conference: March 24, 2011

Earth Loops

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SYSTEM EQUIPMENT WATER SOURCE HEAT PUMPS Maintenance (3 Important Points) Maintenance (3 Important Points)

  • Proper water flow - ± 5% Automatic Flow

Regulators or Pressure Independent Control g p Valves on WSHP’s.

  • Clean water (Clean Heat Transfer Surfaces) –

Combination Air Separator / Particle Separator or small side stream separator for continuous cleaning of water.

  • Proper air flow – Regular Scheduled Air Filter

Replacement and/or differential pressure alarm across air filter across air filter.

Ground Source Heat Pumps – An Overview SCO Conference: March 24, 2011

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IS GROUND SOURCE A GOOD CHOICE FOR YOU ? CHOICE FOR YOU ?

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IS GROUND SOURCE A GOOD CHOICE FOR YOU ? EXAMPLE PROJECT Life Cycle Cost Comparison Life Cycle Cost Comparison

  • New 8600 SF Visitor Center
  • Energy Simulation Software: eQuest DOE2.2 Software
  • Well Design Software: Gaia GLD2010
  • Baseline: Air Cooled Heat Pumps (ASHRAE 90.1)

Alt t G th l H t P

  • Alternate: Geothermal Heat Pump
  • First Cost is incremental to Baseline

Ground Source Heat Pumps – An Overview SCO Conference: March 24, 2011

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IS GROUND SOURCE A GOOD CHOICE FOR YOU ? EXAMPLE PROJECT Well Test Data (different locations) Well Test Data (different locations) City Depth Thermal Conductivity Thermal Diffusivity Formation Temperature A h ill 450 2 03 1 39 58 Asheville 450 2.03 1.39 58 Charlotte 300 1.25 0.84 61 Raleigh 300 1.73 1.2 61 g Elizabeth City 300 1.04 0.71 63

Ground Source Heat Pumps – An Overview SCO Conference: March 24, 2011

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IS GROUND SOURCE A GOOD CHOICE FOR YOU ? EXAMPLE PROJECT Asheville Asheville Air cooled HP: Energy Performance 60 8 kBtu/sqft/yr Energy Performance 60.8 kBtu/sqft/yr Utility Cost $10,275 30 Life Cycle Cost $843,549 Geothermal: Energy Performance 36.8 Kbtu/sqft/yr Utility Cost $6 310 Utility Cost $6,310 30 Life Cycle Cost $726,623

Ground Source Heat Pumps – An Overview SCO Conference: March 24, 2011

SIR Value 2.58

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SLIDE 81

IS GROUND SOURCE A GOOD CHOICE FOR YOU ? EXAMPLE PROJECT Charlotte Charlotte Air cooled HP: Energy Performance 59 2 kBtu/sqft/yr Energy Performance 59.2 kBtu/sqft/yr Utility Cost $10,012 30 Life Cycle Cost $915,581 Geothermal: Energy Performance 37.2 kBtu/sqft/yr Utility Cost $6382 Utility Cost $6382 30 Life Cycle Cost $772,903

Ground Source Heat Pumps – An Overview SCO Conference: March 24, 2011

SIR Value 3.92

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SLIDE 82

IS GROUND SOURCE A GOOD CHOICE FOR YOU ? EXAMPLE PROJECT Raleigh Raleigh Air cooled HP: Energy Performance 61 5 kBtu/sqft/yr Energy Performance 61.5 kBtu/sqft/yr Utility Cost $10,402 30 Life Cycle Cost $915,172 Geothermal: Energy Performance 37.2 kBtu/sqft/yr Utility Cost $6380 Utility Cost $6380 30 Life Cycle Cost $783,844

Ground Source Heat Pumps – An Overview SCO Conference: March 24, 2011

SIR Value 6.72

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SLIDE 83

IS GROUND SOURCE A GOOD CHOICE FOR YOU ? EXAMPLE PROJECT Elizabeth City Elizabeth City Air cooled HP: Energy Performance 64 6 kBtu/sqft/yr Energy Performance 64.6 kBtu/sqft/yr Utility Cost $10,913 30 Life Cycle Cost $963,222 Geothermal: Energy Performance 36.6 kBtu/sqft/yr Utility Cost $6281 Utility Cost $6281 30 Life Cycle Cost $763,327

Ground Source Heat Pumps – An Overview SCO Conference: March 24, 2011

SIR Value 8.50

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SLIDE 84

IS GROUND SOURCE A GOOD CHOICE FOR YOU ? EXAMPLE PROJECT Conclusions Conclusions

  • Geothermal Heat Pump Systems are

significantly more efficient than Air-to-Air g y Heat Pump Systems

  • Drilling cost is more important to payback

than thermal conductivity, although, both are important factors.

Ground Source Heat Pumps – An Overview SCO Conference: March 24, 2011

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SLIDE 85

IS GROUND SOURCE A GOOD CHOICE FOR YOU ? CONSIDERATIONS Challenges Challenges

  • Limited zoning capabilities
  • Heat pump unit noise must be

considered in their placement.

  • Higher first cost
  • Requires well field installation

ti expertise

Ground Source Heat Pumps – An Overview SCO Conference: March 24, 2011

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SLIDE 86

IS GROUND SOURCE A GOOD CHOICE FOR YOU ? CONSIDERATIONS Advantages Advantages

  • Improved Energy Efficiency
  • Water is a better heat transfer medium

(requires 90% less transport energy than air)

  • Heat or cool on demand, during or after hours,

regardless of season, regardless of what other zones are doing

  • Failure of one unit does not affect any others

Ground Source Heat Pumps – An Overview SCO Conference: March 24, 2011

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SLIDE 87

IS GROUND SOURCE A GOOD CHOICE FOR YOU ? CONSIDERATIONS Advantages Advantages

  • Piping typically does not require expensive

insulation

  • Basic thermostat is all that is required (easily

adapts to BMS control)

  • No equipment outside (improved aesthetics)

Si l i t ( ll li t d

  • Simple maintenance (smaller uncomplicated

units are easy to service or remove and exchange if required)

Ground Source Heat Pumps – An Overview SCO Conference: March 24, 2011

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SLIDE 88

SUMMARY

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SLIDE 89

SUMMARY WHAT HAVE WE LEARNED ?

  • Heat pump basics

Heat pump basics

  • Geothermal basics
  • How to mange site design
  • Equipment offerings
  • Performance factors

C id ti f

  • Considerations for your

next project

Ground Source Heat Pumps – An Overview SCO Conference: March 24, 2011

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SLIDE 90

THANK YOU FOR YOUR TIME

Ground Source Heat Pumps – An Overview SCO Conference: March 24, 2011