Geothermal Heating & Cooling Systems (Residential &


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short overview of geothermal home heating technology, components and savings

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Geothermal Heating & Cooling Systems (Residential &

  1. 1. Geothermal Heating & Cooling Systems (Residential & Small Commercial) Bill Durkin <ul><li>What it is not </li></ul><ul><li>Technology </li></ul><ul><li>Components </li></ul><ul><li>Sustainability </li></ul><ul><li>Other benefits </li></ul><ul><li>Related System Designs </li></ul>
  2. 2. Large Scale Geothermal Heating <ul><li>Utilizes steam from geysers </li></ul><ul><li>Large scale utility power plants </li></ul><ul><li>Converts steam into electricity using steam turbines </li></ul><ul><li>Application limited to specific areas </li></ul>
  3. 3. Technology <ul><li>A geothermal heat pump is equipment which uses the ground or ground water as a thermal energy source to heat a building, or as a thermal energy sink to cool a building </li></ul><ul><li>&quot; Ground source heat pump &quot; means the same thing, and the terms can be used interchangeably. &quot;Ground source&quot; differentiates this type of heat pump from an &quot;air source&quot; heat pump, which uses the air as the heat source or heat sink. For example, your refrigerator is &quot;air source&quot; since it uses the air in your house as the heat sink for the heat that it removes from your food. </li></ul><ul><li>The process of elevating low-temperature heat to over 100 degrees and transferring it indoors involves a cycle of evaporation, compression, condensation and expansion. </li></ul>
  4. 4. Geothermal System Components <ul><li>Building </li></ul><ul><li>Distribution System </li></ul><ul><ul><li>Air Handler, ductwork with forced hot/cold air </li></ul></ul><ul><ul><li>Radiant floor system </li></ul></ul><ul><li>Heat Exchanger </li></ul><ul><li>Compressor </li></ul><ul><li>Ground Loop system </li></ul><ul><li>Pump </li></ul>
  5. 5. Geothermal System Components <ul><li>Cooling Mode </li></ul>
  6. 6. Vertical Ground Loop <ul><li>Used when yard space is limited </li></ul><ul><li>Minimum disruption of the landscaping </li></ul><ul><li>Require less piping than horizontal loops because, deeper down, the Earth is cooler in summer and warmer in winter. </li></ul>
  7. 7. Horizontal Ground Loops <ul><li>Large yard space </li></ul><ul><li>No drilling; trenching 3’ to 6’ feet </li></ul><ul><li>400 to 600 feet long per ton of heating and cooling capacity </li></ul><ul><li>Must be below freeze line in colder climates (for water based systems) </li></ul><ul><li>can be installed under existing buildings or driveways (horizontal boring) </li></ul>
  8. 8. Pond Loop System <ul><li>If a pond or lake is used, may be the most economical. </li></ul><ul><li>Pipe may be coiled in a slinky shape to minimize space requirements </li></ul><ul><li>Requires minimal pond/lake depths </li></ul><ul><li>Dependent on local codes </li></ul>
  9. 9. Open Loop System <ul><li>Requires large, reliable water source </li></ul><ul><li>Can also be used use to heat/cool domestic hot water and potable water </li></ul><ul><li>Local environmental officials should be consulted whenever an open loop system is being considered </li></ul>
  10. 10. Sustainability <ul><li>Responsible use of natural resources </li></ul><ul><li>(Sunlight stored in thermal mass – earth) </li></ul><ul><li>Geoexchange systems represent a savings to homeowners of 30 to 70% in the heating mode and 20 to 50% in the cooling mode, compared to conventional systems. </li></ul><ul><li>No onsite carbon emissions; less fossil fuels used </li></ul><ul><li>Due to the earth’s thermal properties, for every electricity unit the geothermal system uses, it generates three to four units of heat energy, an efficiency rating of 300 to 400 percent </li></ul><ul><li>Electrical needs can be met with Photovoltaic panels </li></ul>
  11. 11. Other Benefits <ul><li>Today there are now more than 1,000,000 geoexchange installations in the United States. The current use of geothermal heat pump technology has resulted in the following emissions reductions: </li></ul><ul><ul><li>Elimination of more than 5.8 million metric tons of CO2 annually </li></ul></ul><ul><ul><li>Elimination of more than 1.6 million metric tons of carbon equivalent annually </li></ul></ul><ul><ul><li>These 1,000,000 installations have also resulted in the following energy consumption reductions: </li></ul></ul><ul><ul><ul><li>Annual savings of nearly 8 billion KWh </li></ul></ul></ul><ul><ul><ul><li>Annual savings of nearly 40 trillion Btu’s of fossil fuels </li></ul></ul></ul><ul><ul><ul><li>The monumental impact of the current use of geoexchange is equivalent to: </li></ul></ul></ul><ul><ul><ul><ul><li>Taking close to 1,295,000 cars off the road </li></ul></ul></ul></ul><ul><ul><ul><ul><li>Planting more than 385 million trees </li></ul></ul></ul></ul><ul><ul><ul><ul><li>Reducing U.S. reliance on imported fuels by 21.5 million barrels of crude oil per year. </li></ul></ul></ul></ul>
  12. 12. Related System Design Parameters <ul><li>Heating & Cooling load </li></ul><ul><li>House design </li></ul><ul><ul><li>Envelope efficiency </li></ul></ul><ul><ul><li>Thermal mass (passive solar design) </li></ul></ul><ul><li>Ground loop configuration </li></ul><ul><li>Soil conditions </li></ul><ul><li>Water table factors </li></ul><ul><li>Local climate </li></ul><ul><li>Landscaping </li></ul>
  13. 13. Total Life Cycle Costs/Savings <ul><li>Must look at the total costs for a project’s life </li></ul><ul><li>Initial installation costs (<= 30% more than conventional systems) </li></ul><ul><li>Gas and Electrical savings </li></ul><ul><li>(<=70% heating; <=50% cooling) </li></ul><ul><li>Life cycle maintenance (=> 50% savings) </li></ul><ul><li>Supplemental Savings (heating domestic hot water) </li></ul><ul><li>Federal Tax Credit (30%) </li></ul><ul><li>Environmental impact savings $$ </li></ul><ul><li>Cost/Ft 2 Savings (smaller equipment footprint) </li></ul><ul><li>Positive savings after payback period: (5-15 yrs) </li></ul>