Geothermal Loop Systems
There are closed-loop and open-loop systems used in residential, as well as commercial, geothermal systems. An open-loop system is less commonly used, though it is actually simpler in concept and installation. The water is drawn directly from its source, such as an aquifer or other larger groundwater source, and piped into the home, where the heat pump removes the heat energy. The water is either returned to its source or disposed of through surface drainage or a special specified drainfield.
A closed-loop system involves the use of the antifreeze solution circulating in pipes. There are several types of closed loop systems, among them horizontal, vertical, or slinky (coiled) loops. A horizontal loop is more cost effective if there is enough yard space for digging trenches, 3 to 6 feet deep, in which to place the pipes. The pipes are laid in rows in the trenches.
A vertical loop uses less piping, and is the best option when yard space is more limited. The holes in which the pipes are placed are from 150-450 feet deep. Each vertical pipe is connected to a horizontal pipe to and from the heat pump. Even though this system uses less piping, it can be more expensive to install because of the greater depth needed for the trenches.
A slinky, or coiled, loop system uses coiled pipe. The slinky name is due to the fact that the pipe is coiled, and is laid in the trench in overlapping loops. This overlapping is done to lessen the heat exchanger requirements per trench foot, as more piping and more overlap leads to a shorter trench. However, this system does require more piping and can be more expensive.
There is also a unique geothermal system known as the pond loop system. If there is a pond or other body of water nearby deep enough, it is possible to place closed loop coils on the bottom. The cost efficiency of this system is great, and there is little to no environmental impact.
Geothermal System Upgrades and Additions
Whatever system one chooses, there are also many features that can be included on the heat pump to increase efficiency and add capabilities to the geothermal system. Besides both heating and cooling, the system can also be used to produce hot water. Other features that can be added to the heat pump are variable speed blowers and multi-speed compressors, both of which will add efficiency to the system, especially in places where heating and cooling needs are very different (where winters can be very cold and summers very hot, such as the Midwestern states).
Geosolar Systems
Additionally, geothermal heat pumps can be coupled to solar heating to form a geosolar system. This will lead to even greater efficiency and economy in heating and cooling. The system cost is higher, but the cost can be returned through energy savings in as little as 3-10 years. This is technology that could help to decrease energy costs then, as well as be used to combat global warming, since it draws upon natural resources to work, and does not add pollution.
More Eco-Friendly Plumbing Trends
Beyond installing geothermal systems for heating and cooling, there are other green energy saving trends homeowners are beginning to implement more in their homes, particularly in relation to plumbing and water conservation. Some of these new trends or green products include low-flow shower heads, low-flush toilets, faucet aerators, and under-sink flow restrictors. There are dual plumbing systems that can be engineered to recycle and re-use water toilet flushing needs and other uses. Tankless water heaters can also be installed to provide hot water on demand at preset temperatures rather than keeping it in storage. Another option is a solar water heater, able to reduce water heating costs up to 80%.
Installation of any of these innovations in combination with a residential geothermal system for heating and cooling can go a very long way toward making a home much more environmentally friendly. It will also lead to greater energy and cost efficiency over the long term.