Geothermal Heating Achieves 400% Efficiency - Fact or Fiction?

Some claims are pretty wild. You’ve heard them. Eat these gummy candies and shed pounds overnight. Wear these athletic shoes and tone your bum by 40%. Eliminate all allergies with this baby formula. 

Then there’s the claim in the HVAC world that ground source (geothermal) heat pumps deliver comfort with 400% efficiency. Whoa ... fact or fiction? 

Actually, that one’s true.  

MEASURING HEAT EFFICIENCY: ENERGY IN, ENERGY OUT 

The heating efficiency of HVAC systems comes down to two factors: energy in and energy out. Energy in is the amount of energy a system consumes to achieve the warmth you desire. Energy out is the result of that system’s work—the warmed air that keeps you comfortable.  

Both energy in and energy out can be measured. If we measure the energy out and divide it by the energy in, we get a ratio that tells us our system’s heating efficiency—the Coefficient of Performance (COP).  

• When a system takes in 1 unit of electricity and uses it to put out 1 unit of energy in the form of heated air (a 1 to 1 ratio), its COP is 1.   
• When a system takes in 1 unit of electricity and uses it to put out 4 units of heated air (a 1 to 4 ratio), its COP is 4.  

The higher the COP, the more efficient the system. Most conventional heating systems have a COP of 1. Our ground source heat pumps often operate with a COP of 4+.

THE GROUND SOURCE HEAT PUMP ADVANTAGE  

Geothermal systems use special heat pumps to transfer air from below the Earth’s surface to achieve comfortable temperatures in residential and commercial buildings.  

They operate more efficiently than gas-forced air, propane, and oil systems. They even operate more efficiently than air source heat pumps. Their COP values usually range from three to five. Some go higher, depending on the system’s design, ground conditions, and climate.

A system’s COP value is the basis for comparisons expressed in percentages, for example: 

• “Geothermal heat pumps reach high efficiencies (300%-600%) on the coldest of winter nights.” -  The U.S. Department of Energy. (300% and 600% are based on COPs of 3 and 6 respectively.) 
• “With energy efficiency rating of up to 500%, geothermal systems can save homeowners up to 70% in heating and cooling costs.” – Geothermal Energy Solutions, Inc. (500% is based on a COP of 5). 
• “A networked geothermal system can achieve upwards of 500 to 600% efficiencies, which means that for every unit of energy that goes in, five or six units come out!” – Fresh Energy (500% and 600% are based on COPs of 5 and 6 respectively).  

MEASURING COOLING EFFICIENCY  

Our products aren't just efficient when heating, but are great for cooling, too. Just as the COP uses energy in and energy out to measure heating efficiency, EER—or Energy Efficiency Ratio—uses energy in and energy out to measure cooling efficiency. The energy in is the number of watts of electricity used to remove heat (energy out measured in Btu per hour). The higher the EER measure, the greater the efficiency. 

According to energy marketplace EnergySage, geothermal heat pumps typically have EER ratings between 13 and 18. Some heat pumps including “Made in America” models from Enertech boast EERs that exceed 32 and bear Energy Star’s “Most Efficient 2024” designation. 

Visit Enertech today to find ground source heat pumps and other energy-saving products that can dramatically improve your heating and cooling efficiencies.  Have questions about what the process of getting geothermal looks like? We'd be glad to help!