How Do Geothermal Wells And Systems Work?

Geothermal wells use underground steam and hot water reservoirs to heat residential homes and commercial buildings. Geothermal energy is renewable because it is naturally and continuously produced in the sub-surface of the earth. With the rising consumption of fossil fuels like oil, coal, and gas, and the ongoing current global warming crisis, geothermal wells offer an environmentally friendly way of heating and cooling a home. 

Here, in this post, we’ll give you information about how geothermal wells and systems work.

Types of geothermal wells

Open Loop Systems

An open-loop system is a cost-effective option for homeowners looking for easy heating and air conditioning. It is convenient to install and often provides the most energy-efficient performance. Here is how it works: 

An open-loop geothermal system pumps water from a well, pond or lake, into a heat exchanger in a surface-dwelling and then dumps it back into the ground. In this system, water quality is pretty important because poor quality water can cause scaling or complete corrosion of a heat exchanger. To run this system, you would need about 1.5 – 2 gallons of water per minute, per ton of operating capacity. A 3,000-square-foot, well-insulated home would need 10 to 15 gallons per minute. The amount of water used in this system annually averages from 600,000 to 800,000 gallons. The used water usually re-enters the hydrological cycle after several months. 

Closed Looped Systems

A closed-loop system uses several plastic tubes, called the loops, installed deep into the ground or in a body of water where the temperature remains constant throughout the year. In areas exposed to subfreezing temperatures, glycol is added to water to reduce the freezing point of the liquid inside the system. These underground pipes connect to an indoor heat pump to provide heating and cooling. These loops can easily last for over 50 years.

These systems are installed in three different ways:

Horizontal closed-loop systems

Horizontal loops are the most common and cost-effective solution. It only requires a trench depth of 6-10 feet. If you are constructing a new house and there is sufficient land available, this is the best option. These loops need 400-600 feet of pipe for every ton of cooling and heating capacity. The piping configuration in the trenches are done in these ways:

• A single pipe
• Multiple pipes in a narrow trench
• Multiple pipes in a wider trench

In the winter, the water in the pipes absorbs the heat from the soil and circulates it to the exchanger. These systems are used in applications where the topsoil is thin and less soil is available to bury the loop at the required depth.

Vertical loops

If there is a limited ground area available for the loop installation, vertical loops are best suited to the situation. Vertical loops are also used where the soil is too shallow or rocky for trenching. Here holes are drilled 100 to 400 feet deep and about 20 feet apart. The vertical pipes are connected through a U-bend, and then to the heat exchanger in the home. Your contractor will determine the drilling depth after evaluating the conditions at the job site. A typical borehole depth is 150 to 250 feet. For instance, three 200-feet boreholes will be required if you are looking to install 1,200 feet of pipes.

Pond/Lake

If you have a large water body near your home, this may be the lowest cost option. The coil of pipes is placed at the pond’s bottom to capture the geothermal energy and then routed back to the building. The pond should have a depth of over 8 feet and at least 1/3 acre of surface area. 

About John’s Well Drilling

With over 40 years of experience in the industry, John’s Well Drilling is the leading well drilling and servicing company in Delaware. We are accredited by the Better Business Bureau and licensed to conduct well drilling and installation of geothermal systems. Our services include well drilling, pump repair, and replacement, tank replacements, well servicing, geothermal drilling, and agriculture well drilling services. You can call us at 302-734-2211 or fill out our contact form to get a free quote or get in touch with our experts.