Geothermal for Commercial Buildings


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-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.

-Understand the environmental, operational and cost benefits of a geothermal heat pump system.

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Geothermal for Commercial Buildings

  1. 1. 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
  2. 2. GeothermalSystems Geothermal Systems for for CommercialBuildings Commercial Buildings
  3. 3. Presenters: Brian Smith, PE, LEED AP Principal, Allied Consulting Engineering Services Steve Sakakeeny, CPG, LSP, CHMM Principal, SAK Environmental D.J. Quagliaroli President, DRAGIN Geothermal Well Drilling
  4. 4. 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.
  5. 5. Copyright Materials This presentation is protected by US and International copyright laws. 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.
  6. 6. L E Develop an understanding of how a A geothermal heat pump system R operates. N O I B Have the ability to assess if a N J building is a candidate for a G E geothermal heat pump system, C including technical and regulatory T obstacles. I Understand the environmental, V operational and cost benefits of a E geothermal heat pump system. S
  7. 7. H O R I Z O N T A Loops are installed in trenches 5-10 feet below surface. L L Requires 2,500 square feet per ton of cooling. O Generally installed in areas with moist sand or O dirt. P Must understand hydrology.
  8. 8. V E R T I C A L Boreholes are drilled several hundred feet deep. L Requires 200-250 linear feet per ton of cooling. O O P
  9. 9. P O N D L Geothermal loop is installed directly into a pond O or other body of water near the building. O Size and depth of pond must be analyzed to P ensure sufficient capacity. Man made ponds/lakes are often installed to accommodate a pond loop simultaneously adding to the aesthetics of the property.
  10. 10. S T A N D I N G C Wells are drilled 1,000 – 1,500 feet deep. O L Generally installed in areas with shallow bedrock (within 200’) U M Heat transfer medium (water) comes into direct contact with heat sink/source (rock), resulting in N higher efficiency than closed systems.
  11. 11. HOW IT W O RK S
  12. 12. Heat flows downhill From a higher temperature to a lower temperature
  13. 13. 10 BTU Let’s take 1 pound of water at 80°F and heat it to 90°F by adding 10 BTU
  14. 14. 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
  15. 15. Heat What if we could cool 1 pound of water from 50°F to 40°F?
  16. 16. 10 BTU We would get 10 BTU.
  17. 17. Heat What happens when we put heat into water at 212°F ?
  18. 18. Everyone knows Water boils at 212°F.
  19. 19. 970 BTU It takes 970 BTU to change 1 pound of water at 212°F to 1 pound of steam at 212°F.
  20. 20. In Denver, Colorado, water boils at 202°F.
  21. 21. 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
  22. 22. 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.
  23. 23. 40.00 83.255 40.00 83.255 21.662 108.313 21.662 108.313
  24. 24. 40.00 83.255 40.00 83.255 21.662 108.313 21.662 108.313 120.00 274.65 120.00 274.65 45.952 112.914 45.952 112.914
  25. 25. What are the benefits?
  26. 26. Geothermal vs. Conventional
  27. 27. U D E u S u I G N
  28. 28. D E S I G N
  29. 29. D E S I G N
  30. 30. D E S I G N
  31. 31. Boilers
  32. 32. Smoke Stack
  33. 33. Water Chillers
  34. 34. Earth Shaker 2000
  35. 35. Cooling Towers
  36. 36. Legionnella
  37. 37. Project Example: Zero Arrow Street Zero Arrow Street, Cambridge, Massachusetts
  38. 38. Z E R 40,000 Square Feet O A Mixed Use: Office/Black Box Theater R (American Repertory Theater) R O W Urban Setting Heated and Cooled with Three 1,500 Foot S Standing Column Wells T LEED Certified R E E T
  39. 39. Z E R FIRST COSTS OF EACH SYSTEM TYPE O Ground Source Heat Pump (GSHP): A R Wells = 3 x $55,000 = $165,000 R O W Water Source Heat Pump (WSGP): Cooling Tower = $30,000 S Boiler = $12,000 T R Cost Difference: $165,000 – ($30,000+$12,000) = $123,000 E E Other components are approximately equal for T both systems (i.e. heat pumps, ductwork, piping)
  40. 40. Annual Energy Costs Budget Building Design Cooling Heating Interior Pumps Interior Domestic Ventilation Lighting Water kWh 55,311 22,193 1,816 25,058 94,344 70,298 Therms 0 8713 Cost $0.180 $0.180 $0.180 $0.180 $0.180 $0.180 $/KWhr Cost $1.90 $1.90 $1.90 $1.90 $1.90 $1.90 $/Therm Annual $9,955.92 $19,697.56 $326.81 $4,510.36 $16,982.00 $12,653.39 Costs TOTAL $64,978.23
  41. 41. Annual Energy Costs Proposed Design Cooling Heating Interior Pumps Interior Domestic Ventilation Lighting Water kWh 50,097 31,476 594 23,834 94,344 70,298 Therms 0 0 0 Cost $0.180 $0.180 $0.180 $0.180 $0.180 $0.180 $/KWhr Cost $1.90 $1.90 $1.90 $1.90 $1.90 $1.90 $/Therm Annual $9,017.39 $10,547.91 $106.95 $4,290.12 $16,982.00 $12,653.39 Costs TOTAL $48,715.67
  42. 42. Z E R Energy Savings 1 O A WSHP Cooling $9,956 R WSHP Heating $19,698 R O WSHP Total $29,654 W GSHP Cooling $9,017 S GSHP Heating $10,548 T GSHP Total $19,565 R Geothermal Heat Pump Savings: E $29,654 - $19,565 = $10,089 E T
  43. 43. Z E R O A Simple Payback R R O System Cost Differential $123,000 W Geothermal Heat Pump Savings $10,088 S T R E Payback = $123,000 ÷ $10,000/yr. = 12.2 years E T
  44. 44. M A Water Source Heat Pump I Cooling tower water treatment N Cooling tower fan belts T Outdoor piping (roof) exposed to weather E N Cooling tower exposed to weather A VFD’s can be fussy (control of CT fans) N Boiler service (mandatory once/year) C E
  45. 45. M A Ground Source Heat Pump I Building loop water treatment/test and add N chemicals if necessary T Other components (i.e. heat pumps and E water pumps) require equal maintenance for N both systems A N C E
  46. 46. Geothermal Benefits Free heat No fossil fuel hazards Reduced carbon footprint Enhanced serviceability No outdoor noise No visual impact outdoors Positive cashflow day one Savings increase overtime 10% Tax Credit (30% Residential)
  47. 47. Certified Professional Geologists, Hydrogeologists, Chemists Geology Aquifer testing (hydraulic and thermal) Well design Construction inspection Water quality considerations Regulatory permits
  48. 48. Standing Column Well Water circulation in 1 well 800 ft. to 1,500 ft. deep Surface bleed for thermal balance Gravity injection Permitting
  49. 49. Designing to the Environment YOUR ANSWERS ARE UNDERGROUND! Geology affects thermal capacity of well Water yield affects thermal capacity of well Water quality affects: Corrosion rates O&M Regulatory considerations
  50. 50. Aquifer Characteristics Water yield Rock density Thermal conductivity testing – Btu/ft-hr oF
  51. 51. C Brackish water – O corrosion and water management N Collapsing bore hole S I Waste management D Boston Groundwater Trust (Back E Bay) R A T I O N S
  52. 52. Regulatory Permitting: Applicable Rules Underground Injection (UIC) Control Program Groundwater discharge Permit Program (314 CMR 5.00) MADEP Guidelines for Ground Source Heat Pump Wells, February 2009
  53. 53. Regulatory Concerns Data base of injection wells Thermal pollution Cross-contamination of aquifers
  54. 54. Registration under the UIC Program Initial registration Significant system modifications Change in ownership Well closure
  55. 55. Water Quality Testing Required for all open loop wells “Conditional” to “Full” registration Exceedance may require water treatment Copper and Lead on return flow
  56. 56. E NT U RR TS C EN EM Q UIR Other permitting requirements: RE 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
  57. 57. E NT U RR TS C EN EM Q UIR Treatment and expanded RE permitting required if: Water quality limits exceeded, or Using treatment chemicals (i.e. disinfectants, scale inhibitors)
  58. 58. consulting engineering services, inc. Questions? Thank you for your time. This concludes the American Institute of Architects Continuing Education Systems Program. Allied Consulting Engineering Services 215 Boston Post Road Sudbury, Massachusetts 43 Jefferson Boulevard Warwick, Rhode Island 978-443-7888 Environmental, LLC