Geothermal

Heat Pump Systems

What is Geothermal Heating?

The earth acts as a heat exchanger to maintain a comfortable temperature in your home throughout the year by transferring heat between locations. Geothermal systems, which use solar energy stored near the earth’s surface, can be installed almost anywhere in the world. This is different from traditional geothermal energy that taps into the earth’s core and is limited to specific geographic regions.

During cold months, stored solar energy* is drawn from the earth to heat your home, while in warmer months, heat is extracted from the home and returned to the earth. This process involves a geothermal unit inside the home and high-density polyethylene pipes buried outside.

The earth absorbs about 48% of the sun’s solar energy and stores it below the surface.

*you may hear geothermal systems called ground source heat pumps. This is because geothermal systems use ground source energy (stored solar energy) to heat and cool homes.

How Does It Work?

Although outdoor air temperatures fluctuate throughout the year, underground temperatures remain fairly constant because the earth absorbs and stores about 48% of the sun’s solar energy. Consequently, the temperature four to six feet below ground stays between 45°F and 70°F, depending on your location.

A geothermal system leverages this stable underground temperature to provide the most energy-efficient heating and cooling available. Instead of generating heat, a geothermal system transfers heat from one place to another. The heat exchanger, known as a closed-loop system, is buried in the ground and circulates water-based solutions through a series of pipes. This solution captures stored solar warmth and delivers it to the unit inside the house.

During the winter, the geothermal unit distributes this solar heat throughout the house using standard forced air ductwork or radiant floor heating, ensuring comfortable indoor temperatures. In the cooling season, the same geothermal unit reverses the process, removing heat and humidity from the air and depositing it back into the earth through the same loop system to provide air conditioning.

The Power Behind a Geothermal System: The Ground Loop

The loop system is the core of geothermal technology. No matter which option you choose, it will provide energy-efficient comfort and offer 30%-70% savings on utility bills for many years. Your local geothermal dealer will assist you in selecting the appropriate loop system based on a site survey and a detailed energy analysis of your home. Installing a geothermal loop system is like receiving a 70% discount on energy for the lifetime of your home. The ground loop options include:

Horizontal Loop:

Commonly used when adequate land area is available (the home should sit on ½ acre, at least). Loop installers use excavation equipment such as chain trenchers, backhoes, and track holes to dig trenches approximately 5-8 feet deep. Trench lengths range from 100-250 feet per ton, depending on the loop design and application. Directional bore machines can also be used.

Vertical Loop:

Used mainly when land area is limited in new construction or retrofit applications of existing homes. A drilling rig is used to bore holes at a depth of 100-250 feet per ton. A U-shaped coil of high density pipe is inserted into the bore hole. The holes are then backfilled with a sealing solution.

Pond Loop:

This loop style is an option if a large body of water is available within approximately 200 feet of the home. A half acre, 10 to 12 foot deep body of water is needed to support the average home. The system uses coils of pipe typically 300-500 feet in length. The coils are placed in and anchored just above the bottom of the body of water.

Open Loop:

This loop type can be installed if an abundant supply of high-quality well water is available. A typical home will require a well producing 4 to 8 gallons of water per minute. A proper discharge area such as a river, drainage ditch, stream, pond, or lake must be present. Check for local restrictions before selecting a specific discharge method.

Geothermal Heat Pumps qualify for certain federal tax credits, rebates, and other incentives

ENERGY STAR

Find out more through the ENERGY STAR website above.

FAQ

Can a geothermal heating and cooling system be installed in a small yard?

Yes, it can! In this scenario, your local geothermal dealer would more than likely recommend vertical loops, which usually need a 10×10 space for the ground loop system. This means geothermal can work in densely populated, suburban, and rural areas.

Is there a cost difference with the types of ground loop systems?

The cost of installing a ground loop system varies depending on your location, but vertical loops are generally more expensive due to the drilling equipment required. Your local geothermal dealer will conduct a comprehensive analysis to determine the best options for your home and ensure you get the best return on investment. Overall, each ground loop system will offer more long-term savings and comfort compared to traditional HVAC systems.

Can I install a ground loop system on a hill?

You can! Here’s why it still works: the water-based solution flowing through the ground loop system and into the geothermal unit in the home is not being pushed. It’s constantly flowing so there’s no force upward to get it started and keep it going.

Will a geothermal system work with a traditional HVAC system?

Yes it will! These are known as hybrid systems. If you live in a particularly cold area, a geothermal system can be supplemented with a traditional heat source (gas, propane, etc.). The geothermal system provides 90% of your home’s heating requirements, and the traditional heating system kicks in when the outdoor air has reached a certain low temperature. Geothermal systems can work on their own in very cold temperatures, but when paired with a traditional system it sometimes creates the perfect solution for the most efficient heating. It’s about what works best for you and your home’s needs.

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