Geothermal Heat Pumps – Green to the Core

Geothermal Heat Exchanging Loop

Heat “pumps” are nothing more than heat exchangers – they “pump” refrigerant from an external unit (the condenser) to an internal unit (the evaporative coil).  The geothermal heat pump (GHP) works in the same manner – except the condenser uses the earth’s consistent 55°F temperature vs. the outside air’s extremely variable temperature.  The condenser portion of the heating system is laid out in a shallow grid system (horizontal ground loop) or is drilled deep into the earth (vertical ground loop).  The system works by exchanging heat (or more appropriately, energy) between the air in our homes with the consistently heated earth below our feet.  The maintenance costs of the systems are low because the pumps are mechanically simple and the heat exchanger is below ground.  As a rule of thumb, a geothermal heating exchanger costs approximately $2,500/ton plus drilling costs (10k-30k).  On average, GHP’s save 70% of the energy used in operating conventional systems – the pump cannot be offset by the earth’s constant temperature.  So, if you couple a GHP with a PV canopy (electricity to run the pump) you have created a carbon neutral heating and cooling system, produced excess electricty to sell to your utility or run your lights and created shaded, elegant outdoor living space.  Furthermore, the 30% Homeowner Tax Credit with no cap applies to both the GHP and the PV system.  Sounds like a win-win-win to me!

Footing the Green Bill
May 11th, 2009

Footing the Green Bill

Green Improvements

There is no arguing that sustainable architecture is currently more expensive than standard construction. However, your local, state and federal government is here to help!  You can even check with your local utility to see if they offer incentives and rebates. Current utility, local, state and federal incentives for Renewable Energy & Efficiency can be found easily at www.dsireusa.org.  I have found this website to be a valuable resource for determining the total rebate/incentive that exists for using sustainable techniques.  You will be amazed at how much money is available for going Green!   Feel free to visit dsireusa and other website regarding sustainable construction methods and materials.  It will most likely be an awe inspiring investigation.  Aesthetics and affordability are finally becoming a part of Green!