WHAT IS GEOTHERMAL HEATING AND COOLING?

Highly efficient geothermal systems use a small amount of energy to capture and move a large amount of free energy. In a typical home, 70% of the total energy bill comes from heating, cooling and hot water. As a result, the greatest opportunity to reduce your energy costs is to improve the efficiency of your heating, cooling and hot water system by utilizing this “down to earth” technology. And this energy source is free, renewable, clean and environmentally-friendly. A geothermal system captures this free energy from the earth by using a series of pipes (an earth loop) buried in the ground.

During the heating mode, a special fluid circulates through the pipe where heat energy is transferred from the ground (the heat source) to the fluid and then to the geothermal unit located in the home, providing warm comfort to the structure. Inside the home, the heat can be distributed through either a conventional duct system or a hydronic radiant heat system.

To provide air conditioning, the process reverses. Heat is removed from the home and transferred to the loop fluid. As the warm fluid travels through the pipe in the earth, it is cooled. In the cooling mode, the earth serves as a “heat sink,” a place to deposit the heat removed from the home. In addition to earth loops, geothermal systems can also use a pond, lake or well water as the heat source or heat sink to provide heating and cooling comfort for the home.

As an additional benefit, geothermal can return to you some or all of your hot water efficiently, saving you money. Connecting your water heater, the geothermal unit will deliver hot water to the tank during the heating and cooling process. The heat removed from your home during cooling is deposited into your water heater providing you with virtually free hot water.

A geothermal system can easily be installed in most homes – new or old, large or small.

With many sizes, configurations and options available, the system will be designed and installed to provide the homeowner with many years of reduced energy costs, enhanced comfort, safety and reliability-all from a technology that’s “down to earth”.
Selecting a Water Furnace geothermal system is not only a smart investment in affordable comfort, but also a smart investment in the preservation of the environment for generations to come. That’s why it’s “Smarter from the Ground Up.”
The earth loop transfers heat to and from the ground – eliminating the need for fossil fuels. It’s the heart of a geothermal system, and its biggest advantage over ordinary heating and cooling technologies. Earth loops come in two basic types. Closed loops, made of durable, high-density polyethylene pipe, are buried in the earth or submerged in a lake or pond. They transfer heat by circulating a solution of water and environmentally safe antifreeze. Open loops use ground water pumped from a well as a heat source.
The type to use depends on the terrain, the cost of trenching or drilling, the availability of quality ground water, and available space. Your geothermal dealer will help you make the best choice.

Horizontal Trench Loops

If adequate land is available, horizontal loops can be installed. One or more trenches are dug using a backhoe or chain trencher. Polyethylene pipes are inserted and the trenches are backfilled. There are various designs of horizontal loops, using one, two or three circuits in a trench. The more pipe per foot of trench, the shorter the trench can be. Trenches normally range from 100 to 300 feet depending on the design. A typical home requires 1/4 to 3/4 of an acre for the trenches.

Horizontal Slinky Loops

Another type of horizontal loop is called the Slinky. In this installation, a trench is dug with a backhoe several feet deep, and about 3 feet wide. The coils are “layed off” and spaced evenly throughout the length of the trench. (Think of a flattened, stretched out slinky toy.) Slinkys can be designed as “compact” or “extended”. Trench lengths are typically 100 to 150 feet long.

Horizontal Bore Loops

Where there is adequate space for a horizontal loop, but there is a desire to minimize disruption on the surface, the horizontal bore loop may be the preferred solution. This loop type requires special equipment to bore holes horizontally under the surface. This machine has the capability to start at the surface and drill at a slight angle down to a typical depth of 10-12 ft., then drill back to the surface. Using the right technique, the operator can “steer” the drill head to go deeper or shallower, or turn right or left. The drill head emits a radio signal that can be detected by a special device that tells the operator exactly where and how deep it is. A small-diameter tunnel is created underground by displacing soil with pressurized water. The operator drills the horizontal bore, then directs the drill bit to come back to the surface, typically, about 200 ft. away. At that point, two ends of pipe are attached to the end of the drilling pipe in place of the drill bit, and are pulled back through the hole to the header, and until the u-bend at the end of the pipe is buried. This technique allows the loop to be placed underneath homes, basements, wooded lots or even swimming pools. The only digging required is for the header and the supply and return piping into the house. This type of loop is most often used in a retrofit situation to minimize disruption to the landscape.

Vertical Loops

Vertical loops are used where space is limited or where soil conditions are not conducive to horizontal loops. Installing vertical loops requires the use of a drilling rig. Multiple holes are bored about 10 feet apart. A double pipe connected with a U-bend is inserted into each hole. The hole is filled with grout to provide good contact around the pipe and to seal the hole. The vertical pipes are then connected to a header system horizontally a few feet below the surface. The depth of the holes is dependent upon soil/rock conditions and the size of the system. Although most holes are bored about 100 to 250 feet deep, there is no “magic depth” that needs to be reached. Capacity is not based on depth; rather how much pipe is in the ground and the overall thermal conductivity of the borehole.

Pond Loops

If an adequately sized body of water is close to your home, a pond loop can be installed. A series of closed loops can be coiled and sunk to the bottom. A 1/2-acre, 8-foot-deep pond is usually sufficient for the average home. Ideally, the pond should be close to the home (less than 200 ft.). If the pond is farther from the home, the benefit of using a pond loop is reduced due to added trenching, materials and pumping costs. Pond loop coils are connected together on dry land, and then floated into location. Once filled with fluid, they will sink to the bottom and remain there. Generally, a 300-ft. coil is used for each ton of capacity. This is less pipe than is used in an earth loop because water is a better conductor of heat energy. Pond loops are a cost-effective way to install a geothermal system, because trenching is limited to only the supply and return piping from the pond to the house.

Open Loop-Well System

With an abundant supply of quality well water if available, an open loop system can be installed. A proper discharge site, such as a ditch, field tile, stream, or pond, must also be available. Be sure to check all local codes before selecting a discharge method. This installation usually costs less to install and delivers the same high efficiency. Care should be taken when considering using an open loop system. Depending on water quality, periodic cleaning of the heat exchanger inside the unit may be necessary. Well water containing too many contaminants may not be suitable for use with a geothermal system as it may cause the unit’s performance to degrade over time. Proper testing of the water prior to installation is required.

Call the Geothermal experts at Climate Control today!