A house with a solar panel roof and a backyard under construction showing a radiant floor heating system in the concrete slab.

GEOTHERMAL HVAC

A geothermal HVAC system is the greenest, most efficient, and most cost-effective heating & cooling system available. That's because it uses the free heat created by the sun that’s stored in the earth rather than burning fossil fuels. Homeowners using geothermal systems may realize savings of 30-70% on heating costs and 20-50% on cooling costs compared to other conventional systems. That can translate to savings of $1,500 annually.

WHAT IS GEOTHERMAL HVAC?

Terragator for Environmental & Geothermal Drilling
Terragator for Environmental & Geothermal Drilling
Geo Thermal Pipe for Laterals
Geothermal Settling Ponds
Geothermal Grouting
Geothermal Drilling

An illustration of a house with an underground piping system in the yard, including red and blue pipes entering the house and purple pipes laid out in a loop in the yard, likely part of a geothermal heating or cooling system.

The image is blank with a white background and no visible objects or details.

GEOTHERMAL FAQ

Underground temperatures don’t change as dramatically as outdoor temperatures, thanks to the insulating properties of the earth. For instance, four to six feet below ground, temperatures remain relatively constant year-round. A geothermal system capitalizes on these steady temperatures to provide “free” energy. The system typically consists of an indoor handling unit and a buried network of pipes, called an earth loop, and/or a pump to re-injection well.
The pipes that make up an earth loop are usually made of polyethylene. These pipes can be buried under the ground horizontally or vertically, depending on the site's characteristics. If an aquifer is available, engineers may prefer to design an “open loop” system. An open loop system is where a well is drilled into the underground water. Water is pumped up, run past a heat exchanger, and then the water is returned to the same aquifer through “re-injection.”
In winter, fluid circulating through the system’s earth loop or well absorbs stored heat from the ground and carries it indoors. The indoor unit compresses the heat to a higher temperature and consequently distributes it throughout the building as if it were an air conditioner running in reverse.
In summer, the geothermal HVAC system pulls heat from the building and carries it through the earth loop/pump to the reinjection well, which deposits the heat into the cooler earth/aquifer.
Unlike ordinary heating and cooling systems, geothermal HVAC systems do not burn fossil fuel to generate heat; they merely transfer heat to and from the earth. Typically, electric power is used only to operate the unit’s fan, compressor, and pump
A geothermal cooling and heating system has three main components: Firstly, the heat-pump unit, second the liquid heat-exchange medium (open or closed loop), and third the air-delivery system (ductwork) and the radiant heating (in the floor or elsewhere) if applicable.
The geothermal heat pump has efficiencies rated according to their coefficient of performance, or COP. It’s a scientific way of determining how much energy the system moves versus how much it uses. Most geothermal heat pump systems have COPs of 3.0 to 5.0. To sum up, for every three to five units supplied as heat, one unit of energy is used to power the system.

A person in gloves taking notes on a clipboard with a yellow pencil at a workbench with refrigeration or cooling equipment.

What maintenance is involved?

Geothermal systems require little maintenance. That is to say that appropriately installed, which is critical, the buried loop can last for generations. The unit’s fan, compressor, and pump are housed indoors, protected from harsh weather conditions, so they tend to last for many years, often decades. In short, usually periodic checks, filter changes, and annual coil cleaning are the only required maintenance.

TEN MYTHS ABOUT GEOTHERMAL HVAC

Fact: Geothermal HVAC systems use only one unit of electricity to move up to five units of cooling or heating from the earth to a building.
Fact: Geothermal HVAC systems remove four times more kilowatt-hours of consumption from the electrical grid per dollar spent than photovoltaic and wind power add to the electrical grid. Those other technologies can undoubtedly play an important role, but geothermal HVAC is often the most cost-effective way to reduce the environmental impact of conditioning spaces.
Fact: Depending on the site's characteristics, the earth loop may be buried vertically, meaning the little above-ground surface is needed. Alternatively, if available, an aquifer can be tapped into, and only a few square feet of real estate is required. Remember, the water returns to the aquifer after passing over a heat exchanger; in other words, it is not “used” or otherwise negatively impacted.
Fact: The systems run very quietly, and there is no equipment outside to bother neighbours.
Fact: Most systems use only water in the loops or lines.

Fact: Systems can be designed to handle multiple loads simultaneously.
Fact: Earth loops can last for generations. The heat-exchange equipment is housed indoors so it typically lasts decades. The expense is much less to replace than putting in an entire new geothermal system since the loop or well is the most pricey to install. New technical guidelines eliminate the issue of thermal retention in the ground so that heat can be exchanged with it indefinitely. In the past, some improperly sized systems did overheat or over-cool the ground over time, to the point that the system no longer had enough of a temperature gradient to function.
Fact: They work just as effectively in cooling and can be engineered to require no additional backup heat source if desired, although some customers decide that it is more cost-effective to have a backup system for just the coldest days if it means their loop can be smaller.
Fact: Geothermal systems consume no water. The water used to exchange heat with the earth is returned to that same aquifer. In the past, some “pump and dump” operations wasted the water after passing over the heat exchanger, but those are exceedingly rare now. Geothermal HVAC systems eliminate millions of gallons of water that would have typically evaporated in cooling towers in traditional systems.
Fact: Federal and local incentives typically amount to between 30 and 60 percent of the total geothermal system cost, which can often make the initial price of a system competitive with conventional equipment. Standard air-source HVAC systems cost around $3,000 per ton of heating or cooling capacity during new construction (homes usually use between one and five tons). Geothermal HVAC systems start at about $5,000 per ton and can go as high as $8,000 or $9,000 per ton. However, new installation practices are reducing costs to the point where the price is getting closer to conventional systems under the right conditions.

*price estimates are in US$