What Is a Geothermal Heat Pump?

Geothermal heat pumps use the consistent temperature underground to provide reliable heating and cooling, setting them apart from other HVAC systems. While they can be expensive to install, geothermal systems are one of the most efficient and eco-friendly options available, often leading to long-term energy savings. Think of it like tapping into a naturally heated blanket under your backyard.

If you’re wondering how they work and if they’re right for your home, we have answers in this comprehensive guide. Let’s take a closer look.

How Does a Geothermal Heat Pump Work?

Unlike the outside air, the temperature a few feet underground stays steady throughout the year, usually between 50-60°F in most of the U.S. A geothermal heat pump uses these stable temperatures to provide homes with both heating and cooling.

The most common type of geothermal system operates using a series of pipes, known as a closed-loop system, which are buried 4-6 feet underground near your home. These pipes are filled with water or a water/antifreeze mixture.

During the winter, the liquid in the loop absorbs heat from the earth and transfers it into your home. In the summer, the system works in reverse by carrying heat out of your home and releasing it back into the ground. Inside your home, a heat pump moves the conditioned air through your ductwork, functioning similarly to a traditional furnace or central air conditioning system.

Unlike conventional heating systems that create heat by burning fuel, geothermal units move heat to and from the ground – a process that’s far more efficient. This method of heat transfer not only lowers energy consumption but also reduces environmental impact, making it a sustainable heating and cooling solution.

How Geothermal Compares to Other Heat Pumps

Air-source heat pumps are growing in popularity, but their performance depends on outside temperatures. In very cold weather, traditional heat pumps start losing efficiency once the temperature dips below 40°F. However, HVAC manufacturers are developing cold-climate models that can still operate effectively in below-zero temperatures.

Geothermal systems don’t have that problem, though, because the ground temperature doesn’t change much. That means they can maintain high performance year-round, even in freezing winters or scorching summers. In fact, geothermal heat pumps are often three to five times more efficient than standard HVAC systems.

Types of Geothermal HVAC Systems

Geothermal systems are generally divided into closed-loop and open-loop designs. The best choice for your home usually depends on the size of your property, soil conditions, and available water sources.

• Closed-loop systems: These are the most common. A sealed loop of pipes circulates water or an antifreeze solution underground. Closed-loop setups can be installed in different ways:
• Open-loop systems: Instead of a sealed loop, these systems use well water directly for heat exchange before discharging it. They’re only possible if you have a clean, plentiful water supply that meets environmental regulations.

For most homeowners, a closed-loop horizontal system is the best option if you have adequate yard space.

What Are the Benefits of a Geothermal Heat Pump?

A few reasons homeowners might consider geothermal systems include:

Energy Efficiency

Geothermal heat pumps are the Rolls-Royce of HVAC systems (minus the chauffeur) in terms of performance, often achieving Coefficient of Performance (COP) ratings of 3 to 6, or 300-600% efficiency, on the coldest winter nights. This means they use less electricity to produce the same amount of heating or cooling, which reduces overall energy consumption

Environmentally Friendly

Because geothermal systems do not burn fossil fuels to generate heat, they produce no greenhouse gas emissions, unlike systems that rely on natural gas or oil. Geothermal energy is also a renewable resource, making it a sustainable choice for long-term energy needs.

Lower Operating Costs

Although the initial installation can be more expensive, the savings on energy bills can offset the upfront costs over time. Geothermal heat pumps can reduce energy usage by about 30-60%, according to the U.S. Department of Energy.

Longevity and Durability

Geothermal heat pumps last longer than conventional HVAC systems. The underground components can last 50 years or more, while the indoor components have a lifespan of about 25 years. You’ll benefit from not needing to replace your HVAC system every 15-20 years.

Quiet Operation

Unlike standard central air conditioning or heat pump systems, geothermal heat pumps do not have a loud outdoor condenser unit, making them a quieter option.

Cost and Incentives

Of course, all those perks don’t come cheap. Installing a geothermal heat pump often costs between $15,000 and $35,000, depending on the system design, home size, ground conditions, geographic location, and manufacturer.

The energy savings can make up for the investment in as little as 5-10 years. The federal government also offers a 30% tax credit on installation costs, but those incentives are set to expire at the end of 2025. Some states and utility companies also provide rebates or special financing to make geothermal more affordable.

Can Anyone Install a Geothermal Heat Pump?

Not every home is a good fit for a geothermal heat pump. Horizontal loop systems need a lot of yard space. Vertical loops can be installed on smaller lots, but they require drilling, which adds cost. Soil and rock conditions can also play a role in whether installation is practical. Additionally, some regions may have regulatory or environmental restrictions that limit geothermal installations.

If you’re interested, have a professional HVAC dealer perform an evaluation. They can tell you what system design would work and provide an estimate.

Maintenance Requirements for Geothermal Systems

Geothermal systems don’t require a lot of upkeep. The underground loop is sealed and built to last for decades without attention.

However, like traditional HVAC systems, the indoor equipment needs regular maintenance. You should replace the air filter regularly and schedule at least one tune-up per year to make sure everything is working properly.

Because there’s no outdoor condenser exposed to weather, maintenance costs are usually lower than with traditional heating and cooling equipment.