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Source of Heat Energy
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Commonly Referred to as:
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Location of Heat Energy
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Collection System Design
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Collection Method
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Requirements
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Ground near surface
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‘Horizontal or Surface Collector’
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1 meter below the surface
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Trenches with each length of collector 1 meter apart
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‘Closed Loop’ system using water & antifreeze mix circulating in plastic collector pipe
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Relatively large area of land that can be excavated e.g. 400m2 for a 3-4 bedroom house
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Ground/ rock deep below the surface
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‘Borehole or Vertical Collector’
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Typically borehole(s) down to depth between 80 – 200 meters
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Borehole(s) drilled by specialist contractor
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Closed Loop’ system using water & antifreeze mix circulating in plastic borehole collector pipe
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Borehole of approx. 140m depth e.g. for a 3-4 bedroom house
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Large body of surface water
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‘Lake Collector’
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At bottom of the lake
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Collector pipe weighted and sunk to bottom of the lake
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‘Closed Loop’ system using water & antifreeze mix circulating in plastic collector pipe
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Relatively large body of water, at least 1.5m deep within 100m of the property
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Ground water / aquifer
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‘Open Loop’
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Typically in ground water / aquifer at depth between 30 – 80 meters
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Supply and return boreholes drilled by specialist contractor
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‘Open Loop’ with water pumped up from borehole, through heat exchanges and returned to same aquifer
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Guaranteed flow of 0.5 litres per second e.g. for a 3-4 bedroom house
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