How It Works Photo Gallery

During the site survey we meet with the customers and determine the most appropriate location for the trenching or boring of the wells. The area needed for geothermal systems is much less than customers typically expect and is dependent upon the size of the unit required for the home or building.

 

The pipe placed into the ground is made of high-density polyethylene and carries a 30 year warranty and is expected to last at least 50 years. Polyethylene itself is the most widely used plastic in the world and has annual production of approximately 80 million metric tons.

 

A horizontal closed loop field is composed of pipes that run horizontally in the ground. The horizontal trench, typically 5-6 feet deep, is excavated and a U-shaped polyethylene pipe is placed horizontally inside the same trench. Excavation for horizontal loop fields are less than the cost of vertical drilling, so this is the most common layout used wherever there is adequate land available.

 

Once installed, the area above the trench can be used for almost any purpose as would occur if the trench was not located below. The pipes are very durable and can withstand tremendous pressures placed upon them.

 

A vertical closed loop field is composed of pipes that run vertically in the ground. Vertical fields are typically used when there is a limited area of land available. A hole is bored into the ground, typically 75 to 300 feet deep. Pipe pairs in the hole are joined with a U-shaped cross connector at the bottom of the hole. The borehole is commonly filled with a grout surrounding the pipe to provide a thermal connection to the adjoining soil or rock to improve the heat transfer. Thermally enhanced grouts are available to improve this heat transfer. Grout also protects the ground water from contamination, and prevents artesian wells from flooding the property. Bore holes are spaced at least 10 feet apart and the depth depends on ground and building characteristics.

 

Another alternative to trenching, where there is sufficient property but it is landscaped, paved or otherwise, is that the loops may be laid by horizontal directional drilling. This technique can lay piping under yards, driveways, trees, gardens, barns or other structures without disturbing them. This system also differs from horizontal loops and vertical drilling as the loops are installed from one central chamber thereby further reducing the ground space needed. Horizontal directional drilling is often installed retrospectively (after the property has been built) due to the small nature of the equipment used and the ability to bore beneath existing constructions.

 

Customers are often surprised that horizontal loops do not have to be located in uniform places or patterns and can be placed within a variety of locations. The location in the picture to the left is within the center of a small circular driveway and contains a complete loop system.

 

The pipe joining process uses heat fusion, in which two sections of pipe are trimmed and cleaned, aligned, heated to the melting point, brought together, and allowed to cool, thereby joining all pipes in the system into one continues pipe.

Heat fusion results in a joint that is actually stronger than the pipe itself. For reliability, all underground piping must be thermally fused, rather than mechanically coupled.

 

After leaving the internal heat exchanger, the fluid flows through the loop outside the building to exchange energy with the ground before returning. The pipes are joined at the “header”. The header is the point where the fluids, a mixture of water and propylene glycol or methanol, separate into the separate pipes and then slowly release their energy/absorb energy from the earth and return to the home. Insulation is added at this point to ensure that the pipes do not directly or indirectly exchange their temperatures and reduce the efficiency.

 

There are diverse header options available to fit within different styles of trenching.

 

Duct Woik

The internal portion, the ductwork, thermostat, etc., of Geothermal HVAC is identical to that of conventional systems. Thus, retrofitting a home that previously contained a conventional system has very minimal, if any, internal alterations.

 

Geothermal units are virtually identical to conventional systems in size and, therefore, can fit in the same place as a conventional system has been located without the noisy outside unit. Additionally, geothermal systems come in a horizontal model, at no additional cost, and can be located within spaces which have low ceilings such as under stairs, workbenches, crawlspaces, etc.

 

A concentric fitting can easily connect the geothermal unit to your existing or new hot water heater and will pre-heat your hot water during the cooling phase of the unit. This pre-heating can reduce your hot water heater energy consumption by up to 90% to add additional savings whenever you are cooling your home.

 

Once the job is complete, we seed and straw the site. Some settling is to be expected whenever digging into the earth. Therefore, we leave the area above the trench itself slightly mounded so that it will better conform with the surrounding area once the settling occurs.

 

Trenching can be performed in almost any setting on property, even through dense forests as you see here.