The Efficiency of Geothermal Heat Pumps Vs. Propane Furnaces

Just as much as half of all energy used in the home is going to heating and cooling, so your selection of heating equipment could have a significant impact on the environment and your bottom line. While both propane furnaces and geothermal heat pumps may offer high energy efficiency and effective heating performance, geothermal technology generally offers an advantage over propane boilers regarding both energy efficiency and operating expenses.

How Efficiency Works

For any type of heating technology, the efficiency rating reveals just how much of the energy absorbed by the device is transformed into heat for the home. If you obtain a 90 percent efficient furnace, as an instance, you may expect that 90 percent of the propane used by the furnace is transformed into heat. The remaining 10 percent flows through the flue through the combustion process.

Propane Furnace Efficiency

Federal law in the United States requires all propane furnaces sold to have a minimum efficiency rating of 78 percent as of 2013. Many propane furnaces offer higher efficiency, often in the 90 to 95 percent range. Propane furnaces equipped with condensing systems offer efficiency ratings as high as 97 percent, according to Consumer Search. These systems capture excess heat in exhaust gases and use them to heat the home to maximize efficiency.

Geothermal Heat Pump Efficiency

While propane furnaces generate heat, geothermal heating systems pull heat from underground sources and deliver it to the home. Rather than producing heat, these systems use an electric pump to move present heat, which allows them to operate much more efficiently than any leakage. The efficiency of a heat pump is often measured using a coefficient of performance as opposed to a percentage. The coefficient of performance is really a ratio of heat made to energy absorbed to make this heat. A coefficient of performance of 3.0 means that the unit generates three watts of heat for each watt of power it consumes. To change the coefficient of performance to your percent, only multiply by 100, therefore a coefficient of performance of 3.0 translates to 300 percent efficiency. Geothermal heat pumps often offer efficiency ratings of 300 to 600 percent, according to the U.S. Department of Energy. These efficiency evaluations above 100 percent means that the systems really create more energy than they consume.

Cost Implications

The difference in efficiency between geothermal heat pumps and propane furnaces can have major cost implications for homeowners. In a mild climate condition, an average homeowner might require 50 million British thermal units of heat each winter. To make 1 million BTU of heat with a mean geothermal heat pump costs $10.37 as of September 2013, according to the U.S. Energy Information Administration. Exactly the same 1 million BTU costs $31.82 to make utilizing a mean propane furnace. For 50 million BTU, homeowners may expect to pay only $519 per year with a geothermal heat pump, versus $1,591 with a propane furnace.

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