The Science Behind Geothermal Heating and Cooling

Published on: November 29, 2017
Wind turbines in field | Being eco-friendly with geothermal heat | AC Southeast®

Geothermal heat pumps are an eco-friendly alternative to more traditional forms of heating and cooling. If you’re looking for a smart way to maintain home comfort in Tampa, Florida, without putting too much strain on the planet or your wallet, a geothermal system offers all the benefits you’re looking for. Take a look at some of the science behind the brilliant way that a geothermal system works.

The Wealth of Energy in the Earth

When people think of energy resources buried in the earth, they’re usually picturing oil. However, there’s another largely untapped source of energy just beneath your feet. The earth has a layer of magma under its crust, continually producing heat from the decay of materials like potassium and uranium. Within 33,000 feet of the planet’s surface, there’s 50,000 times the energy of all the natural gas and oil on the planet.

Conditions are most favorable for geothermal energy plants in the western part of the United States in areas like Idaho, Nevada, and Oregon. However, you can access some level of geothermal energy anywhere in the country, including the cities within our service area.

How Geothermal Systems Move Heat

Geothermal heating and cooling systems take advantage of the heat under the earth’s surface in another way. Directly below the earth’s surface, the ground maintains a stable temperature year-round that’s typically between 45 and 75 degrees Fahrenheit. In summer, it’s cooler than the surrounding air. In winter, temperatures underground are warmer.

Geothermal heat pumps circulate water or another liquid in loops placed underneath the earth’s surface. Within these loops, the liquid will either absorb or disperse heat. This allows a geothermal system to work year-round, no matter what type of comfort you need. In summer, the liquid will carry excess heat from your home under the earth’s surface where it’s dispersed in the slightly cooler ground. In winter, the liquid enters the ground cold and absorbs heat from the earth, bringing it back up to your home.

The Efficiency of Heat Pumps

Unlike a central heating system, which generates heat itself, a heat pump moves warmth that’s already there. Geothermal systems work very similarly to air source heat pumps. Both are more energy-efficient than central heating and cooling systems. Geothermal heat pumps have several advantages over even their air source counterparts. They are quieter, have a longer lifespan, and require less maintenance. A ground source heat pump is also more reliable than an air source system. The temperature under the earth remains constant in a given area, while the air temperature is always fluctuating.

Types of Geothermal Heat Pumps

Geothermal heat pumps are either closed loop or open loop systems. As the name suggests, a closed loop system has a loop of piping that’s completely closed. Refrigerant circulates within this loop, transferring heat between your home and the ground.

Closed loop systems come in several shapes. Horizontal closed loop systems place pipes in long trenches in the ground that are at least 4 feet deep. Most use at least two lengths of pipe, and some loop the piping to fit more length in a smaller space. Vertical closed loop systems feature long pipes inserted into holes ranging from 100 to 400 feet deep. Several holes are drilled in one area, about 20 feet from one another, with the horizontal connections placed in deep trenches between the deeper U-bends.

A third closed loop system is a pond or lake geothermal heat pump. In this scenario, long horizontal loops are placed underwater at a depth of at least 8 feet.

Finally, you have open loop systems. These use surface body water or well water instead of refrigerant. If clean water is available in one of these forms, you can opt for an open loop system that takes advantage of this unique geological feature near your home or office. ANATE certified HVAC technician can help you explore the options in your area.

If you’re ready to try geothermal heating and cooling for your home, Contact AC Southeast®. We’ll help you choose the right system for your home.