Find out how a geothermal heat pump system functions, how cost-effective it can be, and what other benefits it has.
Since the late 1940s, geothermal heat pumps (GHPs), also known as earth-coupled, ground-source, or water-source heat pumps, have been in use. Instead of using the temperature of the outside air as the exchange medium, they use the earth’s relatively constant temperature.
One of the most effective methods of cooling and heating your house is geothermal heat pumps. Does it fit your needs as an HVAC system? To learn the solutions, continue reading.
Below are other types of heat pumps:
What is a Geothermal Heat Pump?
An earth-source heat pump system extracts heat from the earth and transfers it to your house. They’re vastly more efficient than conventional heating systems because a heat pump doesn’t burn fuel to create warmth; it simply moves existing heat from one place to another.
And because temperatures underground remain a relatively constant 50 degrees F year-round, the system requires a lot less energy to cool your home than conventional air conditioning systems or air-source heat pumps, which use outside air as a transfer medium.
The most popular and reasonably priced to install are air-source heat pumps. Water-source heat pumps are also available.
Pros
- cheaper to operate than other systems. When compared to conventional heating and cooling systems, a geothermal heat pump will immediately reduce your heating and cooling expenses by 20 to 50 percent.
- utilizes solar energy, a clean and renewable resource. With a geothermal heat pump, there’s no onsite combustion and therefore no emissions of carbon dioxide, carbon monoxide or other greenhouse gases. Air quality or safety issues related to combustion are not present inside the home either. (The pump unit does use electricity, which may be generated using fossil fuels.)
- Can be installed in new construction and retrofit situations. Retrofits, however, which call for ductwork modifications, are much more expensive.
- a lot more silent than other cooling mechanisms. Both an outdoor fan and compressor are silent. The indoor unit typically has a refrigerator-like level of noise.
- enduring and low maintenance. Compared to a furnace or traditional AC unit’s lifespan of 15 years or less, the indoor components typically last around 25 years, while the ground loop has a lifespan of over 50 years. The system needs little maintenance because it has fewer moving parts and is shielded from the elements.
Cons
- Not a DIY project. For the most effective system, professional expertise is needed for sizing, design, and installation.
- Still relatively new. That means fewer installers and less competition. which is why prices remain high.
- Landscape disruption from installation is significant. Some lots might not even allow it. Your prized petunias will undoubtedly be crushed by heavy drilling or digging equipment.
How Does a Geothermal Heat Pump Work?
Similar to how a refrigerator transfers heat from its interior to your kitchen, this device also uses heat. Similar in concept, a geothermal heat pump moves heat from the earth to your home (or vice versa). Long loops of underground pipes filled with liquid (water or antifreeze solution) are used to accomplish this. A geothermal heat pump, which serves as both a furnace and an air conditioner in your home, is connected to the loops.
When it’s a heating season, the liquid extracts heat from the earth and sends it to the geothermal heating and cooling system, where it is then transferred to refrigerant coils, where it is dispersed through a forced-air or hydronic system. The process occurs backward during the cooling season. Your home’s heat is removed by the pump and transferred to the earth. Domestic hot water is also available from many units.
Types of Geothermal Heat Pump Systems
Systems with ground loops can be divided into four categories. Three of these — horizontal, vertical, and pond/lake — are closed-loop systems. The open-loop alternative is the fourth type of system. Which is best for the site depends on a number of elements, including climate, soil characteristics, land availability, and local installation costs.
All of these approaches can be used for residential and commercial building applications.
Closed-Loop Systems
A closed loop, typically made of high-density plastic-type tubing and buried in the ground or submerged in water, is used by the majority of closed-loop geothermal heat pumps to circulate an antifreeze solution. The heat pump’s refrigerant and the antifreeze solution in the closed loop are heated by means of an exchanger.
One kind of closed-loop system, known as a direct exchange, pumps the refrigerant through copper tubing that is buried in the ground in a horizontal or vertical configuration instead of using a heat exchanger.
Horizontal
Particularly for new construction where sufficient land is available, this type of installation is typically the most economically viable option for residential installations. Trenches that are at least four feet deep are needed. The two most popular configurations involve either two pipes, one buried at a depth of six feet and the other at a depth of four feet, or two pipes, placed side by side at a depth of five feet in a trench that is two feet wide.
Vertical
Large commercial buildings and schools often use vertical systems because the land area required for horizontal loops would be prohibitive. Vertical loops are also used where the soil is too shallow for trenching, and they minimize the disturbance to existing landscaping.
Pond/Lake
This might be the least expensive choice if the location has a large enough body of water. In order to prevent freezing, a supply line pipe is buried from the building to the water and coil-coil-coil-coil-buried at least eight feet beneath the surface. Only water sources that meet minimum volume, depth, and quality requirements should be used for the coils.
Open-Loop System
The heat exchange fluid in this kind of system circulates directly through the GHP system and is made of well or surface body water. The water eventually returns to the ground via the well, a recharge well, or surface discharge after circulating through the system.
Evidently, this option is only workable in locations with a sufficient supply of relatively clean water and where groundwater discharge is permitted in accordance with all applicable local laws and regulations.
Hybrid Systems
hybrid systems that use a variety of geothermal sources, or systems that combine a geothermal source with ambient air (i.e., a cooling tower), are another technology option. Where cooling needs are notably greater than heating needs, hybrid approaches are particularly effective.
Where local geology permits, the “standing column well” is another option. This type of open-loop system involves drilling one or more deep vertical wells. A standing column has water drawn from the bottom and returned to the top.
The Efficiency of Geothermal Heat Pump System
Due to this, a geothermal heat pump can generate nearly 12,000 Btu of cooling or heating with just one kilowatt-hour of electricity. (On a 95-degree day, a typical heat pump uses 2.2 kilowatt hours to generate the same amount of BTUs.) Geothermal systems are nearly 50% more efficient than the best gas furnaces and have a year-round efficiency that is twice that of the best air conditioners.
Another benefit is that the compressor coils don’t need to be circulated by a loud outdoor fan. Geothermal units simply pump liquid, so they can be parked indoors, safe from the elements. Although they can last much longer, the majority have 10-year warranties.
How Much Does a Ground Source Heat Pump Cost?
The cost of a ground source heat pump installation varies, influenced by the:
- Access to the ground and whether you choose trenches or a borehole to lay the ground loop.
- the size, model, and brand of heat pump that was selected.
- How much heat is required for a space of a certain size?
- Whether it’s a new build or an existing property.
- Whether you’re opting to make any improvements to your radiators to improve the efficiency of the heat pump, or if you are installing radiators or underfloor heating for the first time.
Typical costs are around £24,000 if your ground loop is buried in trenches, and could be around £49,000 if you need to dig a borehole. We advise speaking with at least three installers to get a quote for your heat pump system so you can get the best idea of what your home’s likely costs will be.
Is Geothermal Right for You?
Each year, the United States installs about 100,000 geothermal heating and cooling systems. The demand for geothermal HVAC is really on the rise, according to Bob Donley, customer support manager at GeoSystems LLC in Minnesota.
A few factors to consider that could make your home a fit for a geothermal HVAC system:
- Can you afford the up-front costs and intend to stay in your home for at least four to seven years (new construction) or ten to twelve years (retrofit) so that you can recover the initial costs through energy/cost savings?
- Live on a large lot with a pond or a well. This would enable you to use a less expensive loop system (see Figure D).
- are constructing a new home and have the ability to roll the upfront expenses directly into the mortgage. Costs associated with heating and cooling will be reduced right away.
- have a home with high energy costs. This most likely means that you currently use propane, oil, or electricity for heating and geothermal cooling.
Conclusion: Understanding the Geothermal Heat Pump System
A ground source heat pump, also known as a ground-to-water heat pump, uses the ground’s natural heat to warm your home’s radiators or underfloor heating. It can also warm up water that is kept in a hot water tank so that your faucets and showers will always be hot.
It can eliminate noisy outdoor compressors and fans and reduce heating and cooling costs for homes by 30% to 70%.
FAQs
Which is Better Heat Pump Or Geothermal?
According to the EPA, a geothermal heating and cooling system can reduce energy consumption and corresponding emissions by more than 40 percent as compared to an air-source heat pump, and by over 70 percent as compared to standard heating and cooling equipment.
Do Geothermal Heat Pumps Work in Hot Climates?
While a geothermal heat pump in a hot climate would not be a bad thing, in most cases, people who live in areas with hot summers and very mild winters will not get maximum benefit. They can use air-source heat pumps and not have to worry about the units freezing over in winter.
Is Geothermal Cheaper Than Electric?
With the use of heat pumps, geothermal heating, and cooling systems extract heat energy and transfer it into buildings, saving approximately 50 to 60% on heating and cooling costs, depending on the fuel being compared to.
Is Geothermal Better Than Solar?
With geothermal, the energy you generate will not replace the electricity you use, but it can lower your heating and cooling bills over the long term. On the other hand, solar energy can significantly reduce your need for electricity or even completely replace it, saving you a ton of money each month.
