geothermal for commercial buildings

So called global warming is just a secret plot by wacko tree huggers to make America energy independent, clean our air and water, improve the fuel efficiency of our vehicles, kick start 21st century industries and make our cities safer and more livable. Don’t let them get away with it.

Chip Giller, Grist.Org

Geothermal Systemsfor

Commercial Buildings

Geothermal Systemsfor

Commercial Buildings

Presenters:

Brian Smith, PE, LEED APPrincipal, Allied Consulting Engineering Services

Steve Sakakeeny, CPG, LSP, CHMM Principal, SAK Environmental

D.J. Quagliaroli President, DRAGIN Geothermal Well Drilling

Allied Consulting Engineering Services, Inc. is a Registered Provider with the American Institute of Architects Continuing Education Systems. Credit earned on completion of this program will be reported to CES Records for AIA members. Certificates of Completion for non-AIA members are available on request.

This program is registered with the AIA/CES for continuing professional education. As such, it does not include content that may be construed to be an approval or endorsement by the AIA of any material of construction or any method or manner of handling, using, distributing, or dealing an any material or product. Questions related to specific materials, methods, and services will be addressed at the conclusion of this presentation.

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This presentation is protected by US and International copyrightlaws. Reproduction, distribution, display and use of the presentation without written permission of the speaker is prohibited.

©2009 Allied Consulting Engineering Services, Inc.

consulting engineering services, inc.

Develop an understanding of how a geothermal heat pump system operates.Have the ability to assess if a building is a candidate for a geothermal heat pump system, including technical and regulatory obstacles.Understand the environmental, operational and cost benefits of a geothermal heat pump system.

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Loops are installed in trenches 5-10 feet below surface.

Requires 2,500 square feet per ton of cooling.

Generally installed in areas with moist sand or dirt.

Must understand hydrology.

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Boreholes are drilled several hundred feet deep.

Requires 200-250 linear feet per ton of cooling.

Geothermal loop is installed directly into a pond or other body of water near the building.

Size and depth of pond must be analyzed to ensure sufficient capacity.

Man made ponds/lakes are often installed to accommodate a pond loop simultaneously adding to the aesthetics of the property.

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Wells are drilled 1,000 – 1,500 feet deep.

Generally installed in areas with shallow bedrock (within 200’)

Heat transfer medium (water) comes into direct contact with heat sink/source (rock), resulting in higher efficiency than closed systems.

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From a higher temperature to a lower temperature

Heat flows downhill

Let’s take 1 pound of water at 80°F and heat it to 90°F by adding 10 BTU

10 BTU

Now let’s take 1 pound of water at 90°F and let it cool to 80°F and give up 10 BTU

10 BTU

What if we could cool 1 pound of water from 50°F to 40°F?

Heat

We would get 10 BTU.

10 BTU

What happens when we put heat into water at 212°F ?

Heat

Everyone knows Water boils at 212°F.

It takes 970 BTU to change 1 pound of water at 212°F to 1 pound of steam at 212°F.

970 BTU

In Denver, Colorado, water boils at 202°F.

In the olden days, before microwave ovens,

folks used a Pressure Cooker to cook foods faster.

Water boils at 240 °F at 10 PSIG

250 °F at 15 PSIG

In the classic high school physics experiment water can be made to boil at any temperature by reducing the pressure.

This concept is the basis of modern air conditioning.

Except air conditioners don’t use water they use Halogenated Chloro Fluoro Carbons like Chlorodifluoromethane and Zeotropic blends of Fluorinated Halocarbons like difluoromethane and pentafluoroethane.

40.00 83.255

40.00 83.255 21.662 108.31321.662 108.313

120.00 274.65

120.00 274.65

40.00 83.255

40.00 83.255

21.662 108.31321.662 108.313

45.952 112.914

45.952 112.914

What are the

benefits?

Geothermalvs.

Conventional

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Boilers

Smoke Stack

Water Chillers

Earth Shaker 2000

Cooling Towers

Legionnella

Project Example: Zero Arrow Street

Zero Arrow Street, Cambridge, Massachusetts

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40,000 Square Feet

Mixed Use: Office/Black Box Theater (American Repertory Theater)

Urban Setting

Heated and Cooled with Three 1,500 Foot Standing Column Wells

LEED Certified

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FIRST COSTS OF EACH SYSTEM TYPE

Ground Source Heat Pump (GSHP):

Wells = 3 x $55,000 = $165,000

Water Source Heat Pump (WSGP):

Cooling Tower = $30,000

Boiler = $12,000

Cost Difference:$165,000 – ($30,000+$12,000) = $123,000

Other components are approximately equal for both systems (i.e. heat pumps, ductwork, piping)

Annual Energy Costs

Budget Building Design

$12,653.39$16,982.00$4,510.36$326.81$19,697.56$9,955.92Annual Costs

$1.90$1.90$1.90$1.90$1.90$1.90Cost $/Therm

$0.180$0.180$0.180$0.180$0.180$0.180Cost $/KWhr

87130Therms

70,29894,34425,0581,81622,19355,311kWh

Domestic Water

Interior Lighting

PumpsInteriorVentilation

HeatingCooling

TOTAL $64,978.23

Annual Energy Costs

Proposed Design

$12,653.39$16,982.00$4,290.12$106.95$10,547.91$9,017.39Annual Costs

$1.90$1.90$1.90$1.90$1.90$1.90Cost $/Therm

$0.180$0.180$0.180$0.180$0.180$0.180Cost $/KWhr

000Therms

70,29894,34423,83459431,47650,097kWh

Domestic Water

Interior Lighting

PumpsInteriorVentilation

HeatingCooling

TOTAL $48,715.67

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Energy Savings

WSHP Cooling $9,956WSHP Heating $19,698WSHP Total $29,654

GSHP Cooling $9,017GSHP Heating $10,548GSHP Total $19,565

Geothermal Heat Pump Savings:$29,654 - $19,565 = $10,089

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Simple Payback

System Cost Differential $123,000

Geothermal Heat Pump Savings $10,088

Payback = $123,000 ÷ $10,000/yr. = 12.2 years

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Water Source Heat PumpCooling tower water treatment

Cooling tower fan belts

Outdoor piping (roof) exposed to weather

Cooling tower exposed to weather

VFD’s can be fussy (control of CT fans)

Boiler service (mandatory once/year)

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Ground Source Heat PumpBuilding loop water treatment/test and add

chemicals if necessary

Other components (i.e. heat pumps and water pumps) require equal maintenance for both systems

Geothermal Benefits

Free heatNo fossil fuel hazardsReduced carbon footprintEnhanced serviceabilityNo outdoor noiseNo visual impact outdoorsPositive cashflow day oneSavings increase overtime10% Tax Credit (30% Residential)

GeologyAquifer testing (hydraulic and thermal)Well designConstruction inspectionWater quality considerationsRegulatory permits

Certified Professional Geologists,Hydrogeologists, Chemists

Water circulation in 1 well

800 ft. to 1,500 ft. deep

Surface bleed for thermal balance

Gravity injection

Permitting

Standing Column Well

Designing to the EnvironmentYOUR ANSWERS ARE UNDERGROUND!

Geology affects thermal capacity of wellWater yield affects thermal capacity of wellWater quality affects:

Corrosion ratesO&MRegulatory considerations

Aquifer Characteristics

Water yield

Rock density

Thermal conductivity testing – Btu/ft-hr oF

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Brackish water –corrosion and water management

Collapsing bore holeWaste management Boston Groundwater Trust (Back

Bay)

Regulatory Permitting: Applicable Rules

Underground Injection (UIC) Control ProgramGroundwater discharge Permit Program (314 CMR 5.00)

MADEP Guidelines for Ground Source Heat Pump Wells, February 2009

Regulatory Concerns

Data base of injection wells

Thermal pollution

Cross-contamination of aquifers

Registration under the UIC Program

Initial registration

Significant system modifications

Change in ownership

Well closure

Water Quality Testing

Required for all open loop wells

“Conditional” to “Full” registration

Exceedance may require water treatment

Copper and Lead on return flow

CURRENT

REQUIREMENTS

Other permitting requirements:

Bleed water to dry well –UIC registration

Bleed water to sewer or storm drain – local permit

Bleed water to surface water –not allowed until Massachusetts

federal EPA permit renewed

CURRENT

REQUIREMENTS

Treatment and expanded permitting required if:

Water quality limits exceeded, or

Using treatment chemicals (i.e. disinfectants, scale inhibitors)

Questions?Thank you for your time.

This concludes the American Institute of Architects Continuing Education Systems Program.

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