Geothermal Heating and Cooling Systems

The Clean, Green Energy Alternative

One of the most exciting developments in home heating and air conditioning today is the increasing popularity of geothermal technology for residential and commercial use.

Geothermal systems (also called geo-thermal or GeoExchange systems, a geothermal heat pump, a ground source heat pump or even Earth Energy) use the earth’s own energy – a clean, constantly renewable energy resource – to heat or cool your home or building and even to help provide hot water for domestic use.

How Geothermal Systems Work

You may not realize it, but almost everywhere in North America the temperature of the earth just below the frost line remains quite steady all year round. Typically, the earth’s temperature below the frost line varies from about 45º in the North to about 70ºF in the South. Geothermal systems take advantage of this constant temperature to provide highly efficient heating and cooling. Because the systems use the Earth’s constant temperature as their energy source, they can be used in both very hot and very cold climates. Geothermal systems are so clean U.S. Environmental Protection Agency has called them, "the most energy-efficient, environmentally clean, and cost-effective space conditioning systems available today."

Geothermal systems take advantage of the earth’s own energy source by using fluid circulating through pipes buried in the ground. In the winter, the fluid absorbs heat from the Earth and uses it to heat your interior space. In the summer, heat from indoors is removed by the heat pump and then the fluid in the ground loop takes it back into the earth. Just a small amount of electricity – enough to operate the heat pump, ground loop pump and distribution fan or pump – is needed to make the system work.

As exciting as geothermal systems are, they’re not a new technology. Geothermal and GeoExchange systems have been around for over half a century. Recently, however, improvements in materials and installation methods, and increased interest in clean energy, has made them more popular. So popular, in fact, that there are now over one million geothermal installations in the United States alone!

Clean Energy Means Lower Utility Bills!

Geothermal systems offer significant advantages in environmental and cost savings. Typical owners of geothermal heating and cooling systems report utility bill savings of 25% up to 75% over conventional systems costs. Add in the fact that the “waste” heat removed from interior spaces can be used to provide nearly free hot water with the addition of a desuperheater unit (for an average savings of about 30% on annual hot water costs) and geothermal heat pump systems look even more attractive.

In addition, geothermal systems are clean systems which produce very little greenhouse gasses and carbon monoxide. Compare this to typical fossil fuel combustion home heating and cooling systems, which U.S. Department of Energy’s Office of Geothermal Technologies says produce nearly 40% of all U.S. emissions of carbon dioxide – almost as much as all of the transportation sector produces!

Geothermal systems may or may not cost a bit more to install than conventional heating systems because of the ground loop pipes required. But over time, these systems have some of the lowest life-cycle costs of any heating and cooling option – costs as low as just $1 a day for a typical 2,000 square foot home!

How is a Geothermal Heating and Cooling System Installed?

Because geothermal systems use heat and energy from the Earth, you do need enough space to install ground loop piping to gather that energy, and then a geothermal heat pump and possibly a desuperheater to maintain a comfortable temperature and provide hot water.

How long a loop you’ll need – and how much land you need for the loop – will depend on what type of loop you use, your home’s heating and air conditioning load, soil conditions, climate and landscaping. Generally, bigger spaces need bigger loops, and areas where temperatures can be extreme also need a larger system. A thorough analysis of your needs and conditions will tell you what kind of loop configuration is best.

Loops can be installed horizontally or vertically in the ground or submersed in a pond or lake. Some typical types of loops include:

Horizontal Ground Loops

These are usually the most cost effective provided your land as sufficient space available, and is easy to dig. Trenches are three to six feet in the ground, then parallel plastic pipes are placed in the bottom. Usually you will need 400 to 600 feet of length for every ton of heating and cooling capacity. While it’s easiest to install horizontal loops in new construction, there are horizontal boring machines that allow the loops to be retrofitted with minimal disruption to existing lawns, and even under buildings and driveways.

Vertical Ground Loops

Where land is at a premium, vertical ground loops may make more sense. Vertical holes 150’ to 450’ deep are drilled, and a single loop of pipe is put into each hole. Those pipes are then connected to a horizontal pipe, also underground, which carries the fluid to the geothermal heat pump. Vertical loops can cost more than horizontal loops to install, but because the Earth is cooler in summer and warmer in winter at deeper depths they often require less piping, making them space efficient.

Pond Loops

If you have a pond or other body of water on your property, pond loops can be very economical. Pond loops use submerged sections of piping to circulate fluid. Water levels must remain at least 8 feet deep at their lowest level for efficient use of pond loops, but the system does not damage aquatic life and may be an affordable option.

Open Loop Systems

Open loop systems can be cost effective in areas with plentiful ground water, but they are used fairly infrequently for typical geothermal heating and cooling systems. They do require wells and may need special permits, so local environmental offices must be consulted before an open loop geothermal system can be considered. Another option, a Standing Column Well System, is sometimes used (particularly in the Northeastern region) but again, permits and local zoning must be consulted to determine if such a system is viable in your area.

Once your pipe loops are installed, a geothermal heat pump will be connected to the system to provide for your heating and cooling needs. If you want to take advantage of your geothermal system for hot water, a desuperheater is also installed. These units are typically very compact, and use regular home duct work to distribute the temperate air.

Geothermal systems also typically require far less maintenance and repair that conventional heating and cooling systems. Geothermal heat pumps usually do the work of both a furnace and air conditioner with just one compact unit. Unlike a conventional heat pump, no heat exchange is required where outdoor air is needed, so a geothermal system can be located indoors in a basement or attic, which protects the equipment from the elements and helps avoid mechanical breakdowns. And the units are so quiet most people don’t even realize they’re working!

If you’re ready to start saving money and helping the environment, call Arundel Cooling & Heating Company today!