Geoexchange Space Heating on Geoexchange Space Heating on the Olympic Peninsulathe Olympic Peninsula

A Presentation forA Presentation for

The Retired Scientists GroupThe Retired Scientists Group

Sequim, WashingtonSequim, WashingtonOctober 4, 2007October 4, 2007

Updated 10/4/2007 10:50 AM

Your PresentersYour PresentersRobert Zeff and Pete ProssenRobert Zeff and Pete Prossen

Residents of SequimResidents of Sequim Electronic engineers by professionElectronic engineers by profession Renewable energy advocatesRenewable energy advocates Have built energy-efficient homesHave built energy-efficient homes Involved in solar and GXHP projectsInvolved in solar and GXHP projects Qualified nerdsQualified nerds

DisclaimerDisclaimer

Your presenters are staunch Your presenters are staunch advocates of resource conservation advocates of resource conservation and the use of renewable, earth-and the use of renewable, earth-friendly energy sources. They have friendly energy sources. They have done their best to prepare this done their best to prepare this presentation with full objectivity. Any presentation with full objectivity. Any opinions expressed or implied are opinions expressed or implied are entirely those of the presenters, who entirely those of the presenters, who are proud to make this claim.are proud to make this claim.

““Geoexchange heat pumps Geoexchange heat pumps are the most are the most

environmentally friendly environmentally friendly and efficient heating and and efficient heating and

cooling systems available.”cooling systems available.”-- U.S. Environmental Protection Agency-- U.S. Environmental Protection Agency

This Presentation Will DiscussThis Presentation Will Discuss Introduction to geoexchange heat pumpsIntroduction to geoexchange heat pumps Pros & cons of geoexchange heat pumpsPros & cons of geoexchange heat pumps Earth’s natural heat as a fuel for space heatingEarth’s natural heat as a fuel for space heating Conventional fuels for space heatingConventional fuels for space heating How heat pump performance is specifiedHow heat pump performance is specified Introduction to air source heat pumpsIntroduction to air source heat pumps Energy cost of space heating methodsEnergy cost of space heating methods Shortcomings of air source heat pumpsShortcomings of air source heat pumps Geoexchange heating and cooling cyclesGeoexchange heating and cooling cycles Geoexchange collection loopsGeoexchange collection loops Examples of installed geoexchange systemsExamples of installed geoexchange systems Monitoring geoexchange performanceMonitoring geoexchange performance

Units of MeasurementUnits of Measurement

Imperial (English) units are the Imperial (English) units are the language of the HVAC industry in the language of the HVAC industry in the USA.USA.

(BTU, foot, Watt, second, degree F)(BTU, foot, Watt, second, degree F) Apologies to those who prefers MKS.Apologies to those who prefers MKS.

What is a Heat Pump?What is a Heat Pump?

* “Improved quality” means the heat is delivered at * “Improved quality” means the heat is delivered at a higher and more usable temperature than that at a higher and more usable temperature than that at which it was extracted.which it was extracted.

A machine that extracts heat from one A machine that extracts heat from one medium and delivers it to anothermedium and delivers it to another

In the process the quality of the heat is In the process the quality of the heat is improved*improved*

Two varieties for space heating with regard Two varieties for space heating with regard to mediato media

Air sourceAir sourceWater sourceWater source

Heat Pumps for Space HeatingHeat Pumps for Space Heating

Air source heat pump extraction Air source heat pump extraction medium is outside airmedium is outside air

Geoexchange heat pumpGeoexchange heat pumpextraction medium is mother earthextraction medium is mother earth

Delivery medium in both cases is the Delivery medium in both cases is the conditioned spaceconditioned space

The cycle is reversible for coolingThe cycle is reversible for cooling

Heat Pumps for Space CoolingHeat Pumps for Space Cooling

Extraction medium is the conditioned Extraction medium is the conditioned spacespace

Air source heat pump delivery Air source heat pump delivery medium is outside airmedium is outside air

Geoexchange heat pump delivery Geoexchange heat pump delivery medium is mother earthmedium is mother earth

Introduction to theIntroduction to theGeoexchange Heat Pump (GXHP)Geoexchange Heat Pump (GXHP)

Geothermal Heat Pump (GHP)Geothermal Heat Pump (GHP) Ground Source Heat Pump (GSHP)Ground Source Heat Pump (GSHP) Earth Coupled Heat Pump (ECHP)Earth Coupled Heat Pump (ECHP)

Geoexchange heat pumps Geoexchange heat pumps have been around since have been around since

1945.1945.

akaaka

GXHP HighlightsGXHP Highlights

Special case of a “water source” heat pumpSpecial case of a “water source” heat pump Extracts earth’s natural heatExtracts earth’s natural heat No combustion or emissionsNo combustion or emissions Heating efficiency can approach 500%Heating efficiency can approach 500% Output to either water, air, or bothOutput to either water, air, or both Reversible for high efficiency coolingReversible for high efficiency cooling Quiet operation (relatively speaking)Quiet operation (relatively speaking) Very long service life of 20+ yearsVery long service life of 20+ years Increases property valueIncreases property value Single indoor unit, no outdoor unit to maintainSingle indoor unit, no outdoor unit to maintain

““Water-to-air” and “Water-to-water”Water-to-air” and “Water-to-water”

““input medium” to “output medium”input medium” to “output medium” Nearly all GXHP’s use “water” inputNearly all GXHP’s use “water” input Forced-air systems deliver “air” outputForced-air systems deliver “air” output Hydronic systems deliver “water” outputHydronic systems deliver “water” output Some GXHP models deliver both outputsSome GXHP models deliver both outputs An alternative is “Direct Exchange” (DX)An alternative is “Direct Exchange” (DX) Specialized models for domestic hot waterSpecialized models for domestic hot water

GXHP is not for everyoneGXHP is not for everyone Requires outdoor spaceRequires outdoor space Higher initial cost than alternativesHigher initial cost than alternatives Impractical in some soil typesImpractical in some soil types Shortage of knowledgeable contractorsShortage of knowledgeable contractors Diminished savings if electric rate is highDiminished savings if electric rate is high Retrofit may not be practicalRetrofit may not be practical

Despite these issues, over 650,000 GXHP’s were Despite these issues, over 650,000 GXHP’s were installed in the US during 2005. Resulting installed in the US during 2005. Resulting estimated annual savings are 5.2 billion kWh, 26 estimated annual savings are 5.2 billion kWh, 26 trillion BTU from fossil fuel, reduced electricity trillion BTU from fossil fuel, reduced electricity demand of 1.7 million kW, and avoided emissions demand of 1.7 million kW, and avoided emissions of nearly 4 million tons of COof nearly 4 million tons of CO22..

-- Source: Geothermal Heat Pump Consortium http://www.ghpc.org

Earth’s natural heat sourcesEarth’s natural heat sources

Geothermal reservoirsGeothermal reservoirs High quality, usable for direct heating High quality, usable for direct heating Rare, impractical for residential Rare, impractical for residential

Climate induced (solar)Climate induced (solar) Low quality, ideal for GXHP Low quality, ideal for GXHP Lags seasonal temperature variation Lags seasonal temperature variation Constant temperature below ~30 ft. Constant temperature below ~30 ft.

Geothermal ReservoirsGeothermal Reservoirs

The Climate-induced Mean The Climate-induced Mean Earth TemperatureEarth Temperature

Seasonal Variation vs DepthSeasonal Variation vs Depth

Subsurface Time Lag vs Subsurface Time Lag vs DepthDepth

Specific Heat and Thermal Specific Heat and Thermal Conductivity of SoilsConductivity of Soils

Specific heat as BTU/(lbSpecific heat as BTU/(lb×׺F)ºF) Dry soil ~ 0.20 Dry soil ~ 0.20 Wet soil ~ 0.25 Wet soil ~ 0.25

Thermal conductivity as BTU/(ftThermal conductivity as BTU/(ft××hrhr×׺F)ºF) Dry sand ~ 0.44, wet sand ~ 1.44 Dry sand ~ 0.44, wet sand ~ 1.44 Clay ~ 0.64, wet clay ~ 0.96 Clay ~ 0.64, wet clay ~ 0.96 Loam ~ 0.52 Loam ~ 0.52

Rocks help (no pore space)Rocks help (no pore space)

The Soil as a Fuel SubstituteThe Soil as a Fuel Substitute

Consider a long cylinder in sandy loamConsider a long cylinder in sandy loamSpecific heat = 0.22 BTU/(lbSpecific heat = 0.22 BTU/(lb×׺F)ºF)Conductivity = 0.8 BTU/(ftConductivity = 0.8 BTU/(ft××hrhr×׺F)ºF)Density (including rocks) = 140 lb/ftDensity (including rocks) = 140 lb/ft33

Cylinder’s radius = 1 ft, length = 100 ftCylinder’s radius = 1 ft, length = 100 ftTotal soil volume = 314 ftTotal soil volume = 314 ft3 3 (11.6 yd(11.6 yd33))Total soil weight = 43,960 lbTotal soil weight = 43,960 lb

Available BTU (10 ºF gradient) = 439,600Available BTU (10 ºF gradient) = 439,600(If we can find a way to get it out).(If we can find a way to get it out).

The Thermal Gradient The Thermal Gradient EquationEquation

Fhr ft

ftBTUty conductivi thermal k

ft path of areaA

ft path gradient of lengthL

hr Q for time migrationt

BTU heat ofquantity Q

F gradient thermal kA

L

t

QΔT

2

2

Analyzing the Cylinder of Analyzing the Cylinder of InfluenceInfluence

Extension of the Gradient Extension of the Gradient EquationEquation

kA

L

t

QΔT

n

nn

1

Loop footage BTU/hr Segment length Soil Conductivity (k) Soil Temperature (T) Segment BTU/hr (Q/t)1,600 32,000 100 0.8 55 2000.00

Steady state soil temperature around a

32

34

36

38

40

42

44

46

48

50

52

54

56

58

60

62

4.03.53.02.52.01.51.00.50.0Soil cylinder radius (ft)

Gra

die

nt (

Deg

rees

F)

100 ft. long geoexchange tube segment extracting 2000 BTU/hr

Loop footage BTU/hr Segment length Soil Conductivity (k) Soil Temperature (T) Segment BTU/hr (Q/t)2,400 32,000 100 0.8 55 1333.33

Steady state soil temperature around a

32

34

36

38

40

42

44

46

48

50

52

54

56

58

60

62

4.03.53.02.52.01.51.00.50.0Soil cylinder radius (ft)

Gra

die

nt (

Deg

rees

F)

100 ft. long geoexchange tube segment extracting 1333 BTU/hr

Loop footage BTU/hr Segment length Soil Conductivity (k) Soil Temperature (T) Segment BTU/hr (Q/t)3,200 32,000 100 0.8 55 1000.00

Steady state soil temperature around a

32

34

36

38

40

42

44

46

48

50

52

54

56

58

60

62

4.03.53.02.52.01.51.00.50.0Soil cylinder radius (ft)

Gra

die

nt (

Deg

rees

F)

100 ft. long geoexchange tube segment extracting 1000 BTU/hr

BTU Content of FuelsBTU Content of Fuels Electricity: 1 kWh = 3,412 BTUElectricity: 1 kWh = 3,412 BTU Coal: 1 pound = 12,000 BTUCoal: 1 pound = 12,000 BTU #2 fuel oil: 1 gallon = 138,500 BTU#2 fuel oil: 1 gallon = 138,500 BTU Nat. gas: 100 cf = 107,500 BTUNat. gas: 100 cf = 107,500 BTU Propane: 1 gallon = 91,000 BTUPropane: 1 gallon = 91,000 BTU Butane: 1 gallon = 102,600 BTUButane: 1 gallon = 102,600 BTU Gasoline: 1 gallon = 124,000 BTUGasoline: 1 gallon = 124,000 BTU Cordwood: 1 cord = 18,100,000 BTUCordwood: 1 cord = 18,100,000 BTU Earth: 11.6 cubic yards = ~ Earth: 11.6 cubic yards = ~ ∞∞ BTUBTU

Heat Pump PerformanceHeat Pump Performance

GXHP standard is ISO 13256-1GXHP standard is ISO 13256-1COP: Heating performance metricCOP: Heating performance metricEER: Cooling performance metricEER: Cooling performance metric

ASHP standard is ARI 210/240ASHP standard is ARI 210/240HSPF: Heating performance metricHSPF: Heating performance metricSEER: Cooling performance metricSEER: Cooling performance metric

Combustion furnaces & boilersCombustion furnaces & boilersAFUE: Heating performance metricAFUE: Heating performance metric

About Performance MetricsAbout Performance Metrics

All are ratios as follows:All are ratios as follows: COP (Coefficient of Performance)COP (Coefficient of Performance)

Energy delivered to energy consumedEnergy delivered to energy consumed EER (Energy Efficiency Ratio)EER (Energy Efficiency Ratio)

BTU removed to watt-hours consumedBTU removed to watt-hours consumed HSPF (Heating Seasonal Performance Factor)HSPF (Heating Seasonal Performance Factor)

BTU delivered to watt-hours consumedBTU delivered to watt-hours consumed SEER (Seasonal Energy Efficiency Ratio)SEER (Seasonal Energy Efficiency Ratio)

BTU removed to watt-hours consumedBTU removed to watt-hours consumed COP & EER reflect single set of conditionsCOP & EER reflect single set of conditions HSPF & SEER reflect seasonal averagesHSPF & SEER reflect seasonal averages

Specifying GXHP PerformanceSpecifying GXHP Performance

Per ISO 13256-1 (replaced old ARI 330)Per ISO 13256-1 (replaced old ARI 330) Single point conditionsSingle point conditions For heating (COP) temperatures are:For heating (COP) temperatures are:

Entry Water is 32 °FEntry Water is 32 °FEntry Air is 68 °F DB, 59 °F WB*Entry Air is 68 °F DB, 59 °F WB*

For cooling (EER) temperatures are:For cooling (EER) temperatures are:Entry water is 77 °FEntry water is 77 °FEntry Air is 80.6 °F DB, 66.2 °F WBEntry Air is 80.6 °F DB, 66.2 °F WB

Realizable in Pacific Northwest soils:Realizable in Pacific Northwest soils:COP values 4.5+, EER values 17+COP values 4.5+, EER values 17+

Some claim that efficiency suffered with Some claim that efficiency suffered with change from Freon 22 to Puron 410achange from Freon 22 to Puron 410a

*DB = Dry Bulb, WB = Wet Bulb*DB = Dry Bulb, WB = Wet Bulb

Specifying ASHP PerformanceSpecifying ASHP Performance

Per ARI 210/240Per ARI 210/240 Seasonal averages, imprecise Seasonal averages, imprecise

parametersparameters Tested at fixed conditions, then Tested at fixed conditions, then

adjusted per seasonal modelsadjusted per seasonal models Fan and pump penalties excludedFan and pump penalties excluded HSPF for heating, SEER for coolingHSPF for heating, SEER for cooling National minimum HSPF is 7.7National minimum HSPF is 7.7 National minimum SEER is 13National minimum SEER is 13

Relationship between COP and HSPFRelationship between COP and HSPF

Both are energy ratiosBoth are energy ratios COP:COP:

Single set of conditionsSingle set of conditionsWatt-hours out to Watt-hours inWatt-hours out to Watt-hours in

HSPF:HSPF:Seasonal average conditionsSeasonal average conditionsBTU out to Watt-hours inBTU out to Watt-hours in

Related by “1 BTU = 0.293 Watt-hour”Related by “1 BTU = 0.293 Watt-hour” Unofficial relationship:Unofficial relationship: ““Seasonal COP” = 0.293 × HSPFSeasonal COP” = 0.293 × HSPF For ASHP: HSPF 7.7 = “Seasonal COP” 2.26For ASHP: HSPF 7.7 = “Seasonal COP” 2.26 For GXHP: COP 3.5 = HSPF 11.94For GXHP: COP 3.5 = HSPF 11.94

Specifying Furnace PerformanceSpecifying Furnace Performance

AFUE (AFUE (Annual Fuel Utilization EfficiencyAnnual Fuel Utilization Efficiency)) More a method than a standardMore a method than a standard Percent of fuel BTU content deliveredPercent of fuel BTU content delivered Fan & pump penalties excludedFan & pump penalties excluded Burn time only, does not embrace:Burn time only, does not embrace:

Idle or standing lossesIdle or standing losses

Cold start/finish performanceCold start/finish performanceInsulation or pilot lightsInsulation or pilot lights

Equivalent Energy Cost Equivalent Energy Cost Comparison to a COP 3.5 GXHP @ Comparison to a COP 3.5 GXHP @

6.2 6.2 ¢¢//kWhkWh

AFUE 60 oil furnace @ 43 AFUE 60 oil furnace @ 43 ¢¢//galgal

AFUE 80 oil furnace @ 57 AFUE 80 oil furnace @ 57 ¢¢//galgal

AFUE 90 propane furnace @ 43 AFUE 90 propane furnace @ 43 ¢¢//galgal

AFUE 90 natural gas furnace @ 48 AFUE 90 natural gas furnace @ 48 ¢¢//CCFCCF

71% efficient wood stove @ $66.70/cord71% efficient wood stove @ $66.70/cord Electric resistance heat @ 1.77 Electric resistance heat @ 1.77 ¢¢//kWhkWh

HSPF 7.7 ASHP @ 4 HSPF 7.7 ASHP @ 4 ¢¢//kWhkWh

Or, for a different perspective . . .Or, for a different perspective . . .

Costs per Million Costs per Million DeliveredDelivered BTU BTU 13.7 gal. propane AFUE 80 (~$30.49)13.7 gal. propane AFUE 80 (~$30.49)

($2.22 per gallon, higher in winter)($2.22 per gallon, higher in winter)

Costs per Million Costs per Million DeliveredDelivered BTU BTU 13.7 gal. propane AFUE 80 (~$30.49)13.7 gal. propane AFUE 80 (~$30.49) 9.06 gal. #2 fuel oil AFUE 80 (~$24.27)9.06 gal. #2 fuel oil AFUE 80 (~$24.27)

($2.68 per gallon)($2.68 per gallon)

Costs per Million Costs per Million DeliveredDelivered BTU BTU 13.7 gal. propane AFUE 80 (~$30.49)13.7 gal. propane AFUE 80 (~$30.49) 9.06 gal. #2 fuel oil AFUE 80 (~$24.27)9.06 gal. #2 fuel oil AFUE 80 (~$24.27) 293 kW hours resistance heat (~$18.17)293 kW hours resistance heat (~$18.17)

(6.2¢ per kilowatt hour)(6.2¢ per kilowatt hour)

Costs per Million Costs per Million DeliveredDelivered BTU BTU 13.7 gal. propane AFUE 80 (~$30.49)13.7 gal. propane AFUE 80 (~$30.49) 9.06 gal. #2 fuel oil AFUE 80 (~$24.27)9.06 gal. #2 fuel oil AFUE 80 (~$24.27) 293 kW hours resistance heat (~$18.17)293 kW hours resistance heat (~$18.17) 1163 cf natural gas AFUE 80 (~$15.40)1163 cf natural gas AFUE 80 (~$15.40)

($1.324 per 100 cf, or ~ 1 therm)($1.324 per 100 cf, or ~ 1 therm)

Costs per Million Costs per Million DeliveredDelivered BTU BTU 13.7 gal. propane AFUE 80 (~$30.49)13.7 gal. propane AFUE 80 (~$30.49) 9.06 gal. #2 fuel oil AFUE 80 (~$24.27)9.06 gal. #2 fuel oil AFUE 80 (~$24.27) 293 kW hours resistance heat (~$19.92)293 kW hours resistance heat (~$19.92) 1163 cf natural gas AFUE 80 (~$15.40)1163 cf natural gas AFUE 80 (~$15.40) 0.078 cords Doug fir @ 71% (~$15.17)* 0.078 cords Doug fir @ 71% (~$15.17)*

($195 per cord)($195 per cord)

* BTU delivered is significantly reduced if wood is not well-seasoned* BTU delivered is significantly reduced if wood is not well-seasoned

Costs per Million Costs per Million DeliveredDelivered BTU BTU 13.7 gal. propane AFUE 80 (~$30.49)13.7 gal. propane AFUE 80 (~$30.49) 9.06 gal. #2 fuel oil AFUE 80 (~$24.27)9.06 gal. #2 fuel oil AFUE 80 (~$24.27) 293 kW hours resistance heat (~$19.92)293 kW hours resistance heat (~$19.92) 1163 cf natural gas AFUE 80 (~$15.40)1163 cf natural gas AFUE 80 (~$15.40) 0.078 cords Doug fir @ 71% (~$15.17)0.078 cords Doug fir @ 71% (~$15.17) 130 kW hours HSPF 7.7 ASHP (~$8.06)130 kW hours HSPF 7.7 ASHP (~$8.06)

(6.2¢ per kilowatt hour)(6.2¢ per kilowatt hour)

Costs per Million Costs per Million DeliveredDelivered BTU BTU 13.7 gal. propane AFUE 80 (~$30.49)13.7 gal. propane AFUE 80 (~$30.49) 9.06 gal. #2 fuel oil AFUE 80 (~$24.27)9.06 gal. #2 fuel oil AFUE 80 (~$24.27) 293 kW hours resistance heat (~$19.92)293 kW hours resistance heat (~$19.92) 1163 cf natural gas AFUE 80 (~$15.40)1163 cf natural gas AFUE 80 (~$15.40) 0.078 cords Doug fir @ 71% (~$15.17)0.078 cords Doug fir @ 71% (~$15.17) 130 kW hours HSPF 7.7 ASHP (~$8.06)130 kW hours HSPF 7.7 ASHP (~$8.06) 84 kW hours COP 3.5 GXHP (~$5.21)84 kW hours COP 3.5 GXHP (~$5.21)

(6.2¢ per kilowatt hour)(6.2¢ per kilowatt hour)

-- Source: -- Source: http://eia.doe.gov/ prices for May, 2007 prices for May, 2007

Cost per million delivered Cost per million delivered BTUBTU

$30.49

$24.17

$19.92

$15.40 $15.17

$8.06

$5.21

$0.00

$5.00

$10.00

$15.00

$20.00

$25.00

$30.00

$35.00

Propane Oil Electric Gas Wood ASHP GXHP

Heating Cost at Happy Valley Heating Cost at Happy Valley RoadRoad

2,248 sf single story built in 19952,248 sf single story built in 1995 Conventional constructionConventional construction Forced air heat distributionForced air heat distribution Sited amidst trees, no passive heat Sited amidst trees, no passive heat

gaingain Jan 31 thru Apr 1, 2006Jan 31 thru Apr 1, 2006

920 kWh ($57.04), average $25.93/mo920 kWh ($57.04), average $25.93/mo November 1, ‘06 thru March 31, ’07November 1, ‘06 thru March 31, ’07

3,255 kWh ($202), average $40.36/mo3,255 kWh ($202), average $40.36/mo

Heating Cost at Stampede Heating Cost at Stampede DriveDrive

3,150 sq. ft. two-story built in 20053,150 sq. ft. two-story built in 2005 6” structural insulated panel construction6” structural insulated panel construction On south slope, good passive heat gainOn south slope, good passive heat gain Hydronic radiant floor heat distributionHydronic radiant floor heat distribution January 28, 2006 thru Apr 13, 2006January 28, 2006 thru Apr 13, 2006

1,301 kWh ($80.63), average $32.25/mo1,301 kWh ($80.63), average $32.25/mo

Typical Water-source Typical Water-source PerformancePerformance

Shortcomings of ASHP’sShortcomings of ASHP’s Regional test standard is a compromiseRegional test standard is a compromise Based on high dehumidification needsBased on high dehumidification needs Based on 82ºF outside temperatureBased on 82ºF outside temperature Hotter, dryer climates not consideredHotter, dryer climates not considered No maintenance procedure consideredNo maintenance procedure considered Plate finned coils deteriorate quicklyPlate finned coils deteriorate quickly Installation/maintenance complicationsInstallation/maintenance complications Cannot support hydronic space heatingCannot support hydronic space heating NoisyNoisy Won’t work under a snow driftWon’t work under a snow drift

ASHP to GXHP Retrofit Case StudyASHP to GXHP Retrofit Case Study Military family housing at Fort Polk, LouisianaMilitary family housing at Fort Polk, Louisiana 4,000 units, 5.6 million sq. ft.4,000 units, 5.6 million sq. ft. Initially ASHP with a few gas-heatedInitially ASHP with a few gas-heated Total cooling capacity 6,600 tonsTotal cooling capacity 6,600 tons Other efficiency measures includedOther efficiency measures included Project cost ~$19 millionProject cost ~$19 million Annual electric savings 25.6 million kWh Annual electric savings 25.6 million kWh

(33%)(33%) Annual gas savings 260,000 thermsAnnual gas savings 260,000 therms Maintenance cost capped at 77% of previousMaintenance cost capped at 77% of previous Total annual savings ~$3 millionTotal annual savings ~$3 million

-- Source: -- Source: USDOE "How to Buy an Energy-Efficient Ground Source Heat Pump"

Fort Polk retrofit: Daily electric consumption for 200 homes

EER Decline in an ASHPEER Decline in an ASHP

--Source: Southern California Edison --Source: Southern California Edison Hot Dry Air Conditioner Final Report, July 2007

DesuperheaterDesuperheater Small heat exchanger and circulating pumpSmall heat exchanger and circulating pump Double-wall heat exchanger for potable waterDouble-wall heat exchanger for potable water Supplemental heat for domestic hot waterSupplemental heat for domestic hot water Integrated into the heat pump packageIntegrated into the heat pump package Transfers less than 5,000 BTU/hrTransfers less than 5,000 BTU/hr Beneficial to the cooling cycleBeneficial to the cooling cycle Detrimental to the heating cycleDetrimental to the heating cycle Required to qualify for federal tax creditRequired to qualify for federal tax credit Tax credit is less than the desuperheater costTax credit is less than the desuperheater cost

GXHP Collection LoopsGXHP Collection Loops

Horizontal

Pond

Vertical

Open

Loop Layout at Happy Valley Loop Layout at Happy Valley Rd.Rd.

3-Ton Geoexchange Heat Pump3-Ton Geoexchange Heat Pump

Geo-loop Flow CenterGeo-loop Flow Center

Geoexchange Loop Flow MeterGeoexchange Loop Flow Meter

Kilowatt-hour PulserKilowatt-hour Pulser

Totalizing Kilowatt-hour MetersTotalizing Kilowatt-hour Meters

Modified GXHP Design for SeattleModified GXHP Design for Seattle

Problem: How to put a 300 ft. long trench Problem: How to put a 300 ft. long trench within a typical 5000 sq ft city lot?within a typical 5000 sq ft city lot?

Solution: Use the GXHP design of the late Solution: Use the GXHP design of the late Ralph Schlichtig.Ralph Schlichtig.– Shorten the ground loop so it’s sufficient to Shorten the ground loop so it’s sufficient to

provide heat for only one month.provide heat for only one month.– Place sewer pipe in the ground alongside the Place sewer pipe in the ground alongside the

ground source pipes to serve as an outside air ground source pipes to serve as an outside air tunnel. tunnel.

– Provide heat to the ground by blowing outside Provide heat to the ground by blowing outside air through the tunnel whenever the air air through the tunnel whenever the air temperature is higher than the ground temperature is higher than the ground temperature.temperature.

Underground Piping SchematicUnderground Piping Schematic

Ground Level Exhaust Fan from Tunnel

Sewer Pipe for Air Tunnel

Ground Loop for Working FluidFluid To Heat Exchanger

Fluid From Heat Exchanger

GXHP Ralph Schlichtig’s design utilizes the GXHP Ralph Schlichtig’s design utilizes the very porous soil in the Spokane area.very porous soil in the Spokane area.– Cut a hole in the basement in the center of the Cut a hole in the basement in the center of the

househouse– Use a fan to pull 50Use a fan to pull 50° air directly out of the ° air directly out of the

ground under the house year round.ground under the house year round.– This air is used in a ground air-sourced heat This air is used in a ground air-sourced heat

pump that operates with a high coefficient of pump that operates with a high coefficient of performanceperformance

– No pipes in the ground are neededNo pipes in the ground are needed

Schlichtig GXHP Design for SpokaneSchlichtig GXHP Design for Spokane

Sketch of Spokane Heat PumpSketch of Spokane Heat Pump

Heat Exchanger

50° air from ground Requires very porous soil

““. . and will perform like new for at least 25 . . and will perform like new for at least 25 years”.years”.

Things don’t always work as advertisedThings don’t always work as advertised Poor performance wastes energy and $$Poor performance wastes energy and $$ Eventually something will go wrongEventually something will go wrong Help wanted: Good watchdogHelp wanted: Good watchdog

-- -- AdvertisementAdvertisement

But in the real But in the real world . . .world . . .

Things that went wrong atThings that went wrong atHappy ValleyHappy Valley

Loop circulation pump on half voltageLoop circulation pump on half voltage Desuperheater was an energy sinkDesuperheater was an energy sink

Click to see live performance data from this plant

PhotovoltaicPhotovoltaic Generating Plant Generating Plant

Something went wrongSomething went wrong

that was not discovered by mental telepathy

It was discovered byIt was discovered by

a good watchdoga good watchdog

Optimization Demands MonitoringOptimization Demands Monitoring

Energy conservation systems have an Energy conservation systems have an additional purpose beyond the obvious.additional purpose beyond the obvious.

They cost more. Protect this investment They cost more. Protect this investment and maximize the payback.and maximize the payback.

Keep manufacturers honest.Keep manufacturers honest. Improve the image of conservation Improve the image of conservation

practices.practices. Help squelch the nay-sayers.Help squelch the nay-sayers.

Time for a Shift ChangeTime for a Shift Change

Robert Zeff will now take over to Robert Zeff will now take over to explain and demonstrate his explain and demonstrate his brilliant Windows application to brilliant Windows application to present live operating data from a present live operating data from a working geoexchange heat pump.working geoexchange heat pump.

Stampede Drive Loop LayoutStampede Drive Loop Layout

Stampede Drive Hydronic Stampede Drive Hydronic SystemSystem

Geoexchange Loop at Stampede Geoexchange Loop at Stampede DriveDrive

Geoexchange Loop at Stampede Geoexchange Loop at Stampede DriveDrive

Geoexchange Loop at Stampede Geoexchange Loop at Stampede DriveDrive

Stampede Drive GXHP SystemStampede Drive GXHP System

Want a review?Want a review?

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