Today's blog is looking at geothermal heating and air conditioning and we want to answer some of the questions about geothermal in general.
To start, let's quote a couple of facts Scott, owner and president Carolina Heating Service, has presented in a recent meeting:
- According to the EPA, GeoExchange technology is the most energy-efficient, environmentally-clean and cost-effective space conditioning system available.
- The EPA found that the systems can reduce energy consumption and corresponding emissions by over 40% compared to air source heat pumps and by over 70% compared to electric resistance heating with standard air conditioning equipment.
- Current GeoExchange installations equal 14 million barrels of crude oil saved per year.
- The ground absorbs 47% of the sun’s energy that reaches the earth. This amount of energy represents 500 times more than mankind needs every year.
- The amount of energy the earth receives from the sun in one hour represents more energy than humanity requires in one year.
Even when we assume that these facts are greatly overstated we can conclude that using the energy already present is a smart and money saving move.
How do geothermal systems work? Let's look at the components:
- We have the air ducts in the house providing warm or cold air for heating or cooling. Nothing new here as we have this in all forced air home comfort systems.
- New are the loops in the ground (see graphic) to collect or distribute heat.
These loops exchange cold water against warmer water in heating mode or exchange warm water against colder water in cooling mode. The earth / ground is an infinite source, and sink respectively, for heat energy.
- And in the middle is the heat pump which pumps the energy or heat in heating mode from the loop to the air duct and in cooling mode from the air duct to the loop.
- Water heaters are often part of a geothermal system as heat is available in abundance, especially in summer time.
How about the money saving?
While the heat to and from the earth is a free product of our environment electric energy is typically used to operate the system: run the heat pump, blow the hot or cool air into the house and to pump the water through the ground loops for energy transfer.The experienced ratio of electric energy used to free geothermal energy gained can be as high as 1:4. Compared to traditional heating and air using electricity and fossil fuels we can theoretically estimate savings of up 80%, a pretty good deal.
We already learned from the geothermal facts in the introduction, that even the EPA estimates somewhat lower energy ratio. We can easily imagine that house insulation and windows to name just two influences, influence this ratio drastically . So the actual numbers including equipment needed, thermal conditions of the house and finally an estimate of saving can differ widely from application to application.
Ask your locale heating and air contractor for a detailed estimate of your specific application. And visit www.carolinageoheating.com or contact the Carolina Heating Geothermal Specialists.
This much for now. We will dive into the theory and the practical function of the heat pump itself at a later blog.