Building developers, architects and mechanical engineers are always looking for ways to improve efficiency in HVAC equipment and system design. Geothermal technology continues to gain attention as a cost-effective alternative to conventional heating and cooling systems. Recent enhancements make geothermal a more affordable option for a wide variety of commercial applications.
What Makes Geothermal Technology so Efficient?
Conventional air-source heat pumps are subject to a rapid loss of efficiency during extreme outdoor temperatures as demonstrated by Coefficient of Performance (COP) equations.  Seasonal ambient air temperatures can vary by as much as 60 degrees Fahrenheit in most parts of the country. By contrast, a geothermal system uses the earth itself as the heat transfer mechanism. Since the temperature of the ground below the frost line is stable throughout the year, the energy exchange process is optimized.
Published EER and HSPF efficiency ratings are calculated by using measurements taken over a range of different temperatures, but the actual performance the of unit could be much worse when operating in typical seasonal weather extremes. To understand the negative impact of temperature fluctuations on air source heat pumps, ask your contractor to provide the unit’s extended efficiency ratings.
In contrast, the performance of a geothermal cooling and heating system remains consistent in all weather conditions since the ambient temperature surrounding the heat exchanger loop remains effectively unchanged. The extended ratings for a geothermal heat pump are superior in virtually all weather conditions.