GeoThermal systems are on average 65 to 80% more effiecnt then your traditional Air Conditor. With anywhere from 4 to 12 year payback time frame. On top of that Traditional air conditioners are averagly rated at 75% maintenance cost over a 15 year period. Geothermal systems last much longer; over 30 years usally with just 10% maintenance cost. Geothermal systems do not have any components that are exposed to the outside elements; such as the outside thermal exchanger on traditional air conditioners. Also traditional air conditioners go thur many cycles which increase there rate of wear and tear; for example, normally you air conditioner internal coils freeze, sensors receive this information and revrese the flow of refigrant; this is called the defrost cycle. The constant freeze, defrost action dramtically effects the strength of the metal.