You would have gone through the first part of this article on Direct Use geothermal heating systems, by now.

Ground Source Heat Pumps or GSHPs are on the other hand the most sought after heating systems as these are economically and environmentally important.
They come in 3 main types.

• Ground Coupled Heat Pump systems
• Ground Water Heat Pump systems
• Surface Water Heat Pump systems

The use of terminology in Ground Source Heat Pumps is somewhat confusing even to professionals.
Therefore those who are interested better be prudent when analyzing the pros and cons of systems.

Ground Coupled Heat Pump systems
A ground coupled heat pump or a Closed Loop Ground-Source Heat Pump is a system incorporating a reversible, vapour compression type (i.e. systems which uses compressor driven refrigeration systems) unitary (packaged) unit coupled to a” refrigerant to water” heat exchanger (Condenser).
This is the mostly commonly used residential GCHP in the world and is called “water to air” heat pump.

A closed  loop secondary  liquid (refrigerant) circuit consisting of  water and antifreeze (or at times water only)  circulates it  through a polyethylene “U” tube buried approximately up to 150 meters (if buried in soil vertically or about a meter below ground surface, if buried horizontally), by means of a pump.

Another more efficient but expensive GCHP  uses a  buried copper tube type heat exchanger coupled to an  Expansion Valve/capillary tube throttling device and a change over valve forming Direct Expansion type GCHP.

GCHPs are further sub divided based on the buried heat exchanger coils as follows;

• Vertical –
  uses generally two small bore high density poly ethylene (HDPE) pipes buried in the bore drilled in the soil at a depth between 15m to 180 m depending on several variables. The two pipes are joined together at the end of them forming a “U” tube. Relatively less surface area is required.
• Horizontal –
  Requires a wide surface area.
  Horizontal system may be found as Single Pipe, Multiple Pipe and Spiral pipe types.
  The spiral system requires the least amount of area out of the three types.
  Horizontal GCHP has the advantage of being economical than the vertical.
  Also trained technical personal are readily available.
  Unfortunately due to the shallow position of the coil, the ground temperature and the thermal characteristics vary widely with the season, rain fall and the depth of the loop coil.

Geothermal Heating is one of the most efficient heating systems available today for you.
Greentech.ie can assist you readily with further information and other benefits of geothermal heating systems.

Geothermal Systems are entitled to a grant of Euro 2,000 upwards from Sustainable Energy Authority of Ireland (SEAI).
Interested to know what these Geo Thermal Energy and Geothermal Systems are?
Then this article is for you.
Learn about systems that could rise up to 600% efficiency.

Geothermal Energy
The earth we inhabit is inundated with Solar Energy every day.
A substantial portion of this vast quantity of energy is stored below the surface of the planet and available for useful work, provided it can be harnessed economically and conveniently.
But on the other hand, compared to the inherent thermal energy resources of the planet available under it’s crust and produced by radioactive decay, this solar energy pales in to insignificance.

Geothermal resources can be broadly categorized as;

• High Temperature (i.e. >150 ⁰C) –
  Used generally for the generation of electrical energy.
• Intermediate Temperature – (i.e. <150 ⁰C) –
  Direct Use applications, Ground Source Heat Pumps
• Low  Temperature – (i.e. <32 ⁰C) -
  Ground Source Heat Pumps

The high temperature applications have been in existence for quite some time compared to others and are strictly for high capacity commercial use for power generation.
Intermediate temperature Direct Use applications are often used in district heating etc.

Low grade heat is used strictly for Ground Source Heat Pump systems and is one of the most efficient heating and cooling systems available to us today.

Direct Use Applications
Direct Use Applications mainly consist of five major sub systems.
These are;

• The production System
  (that transfer the geothermal energy to a circulating fluid) inclusive of the Producing Well Bore and associated well head equipment (pumps controls, etc).
• The Transmission and distribution system
  this will transfer Geo thermal Energy from the source to the end-user site and distribute it to the individual terminals (room equipment).
• The End -User system
  (radiators, Fan Coil Units, Packaged Unitary Equipment etc.).
• The used water disposal system which can be surface disposal or injection back in to the original underground locality.
• An optional peaking/backup (auxiliary heating system).

The direct use systems may be;

• Open Loop which include production wellhead equipment, optional peaking/backup unit, user system and the disposal system.
• Closed Loop( Hybrid) where the primary circuit is an open loop incorporating Injection Well Head equipment and production well head equipment inclusive of a Heat Exchanger where the secondary circuit is a closed loop which also includes a pump, peaking/backup unit and the user system.

Direct use systems are susceptible to the quality of water such as presence of Total dissolved Salts (of which there is abundance in deep underground), Hydrogen Sulphide, Sulpher, etc.
Also disposal of water on surface is prohibited in almost all localities and has best be injected back to the source.
The initial capital costs are high though the operation and maintenance cost is very little.

Look out for the sequel in this article on Ground Source Heat Pumps, the most popular geothermal heating system anywhere in the world, which will follow.

Geothermal Heating is one of the most efficient heating systems available for you today.
Greentech.ie can assist you readily with further information and other benefits of geothermal heating systems.