What Is Geothermal Heating And Cooling?

Looking for energy-efficient, cost-saving methods to both warm-up and cool down your home? Then look no further than geothermal heating and cooling! 

One of the fascinating aspects of geothermal energy is that it comes from within our Earth’s crust. As such, it’s more resilient, sustainable, and reliable. So, instead of using a conventional air-conditioner or older oil heating method, you can use a ground heat pump!

In recent years, geothermal heating and cooling have grown massively in popularity — people around the world are investing in these systems for their households and businesses. The results have been promising —many out there have had energy savings of over 50%

Needless to say, you can expect geothermal heating and cooling to continue growing for the foreseeable future.

So grab a cup of coffee and get comfy, you’re going to learn all there is to know about geothermal heating and cooling technology!

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What Is Geothermal Heating And Cooling?

Geothermal heating and cooling is the exchange of heat between the Earth or water, and ambient air temperatures. This renewable energy method usually takes place through circulating fluids and can be used for water temperatures, floor heating, and air cooling.

Essentially, geothermal heating and cooling systems produce area heating, area cooling, and water heating effects using the Earth’s natural temperature range.

Here are the advantages and disadvantages of Geothermal Energy.
The basic concept of geothermal heating and cooling in a household system across seasons.
The basic concept of geothermal heating and cooling in a household system across seasons.
Source: Neuhaus

How Does Geothermal Heating Work?

Many people use geothermal heating for floor heating, but it can also heat water in a house.

When the below-ground temperature is higher than the above-ground temperature, geothermal heat pumps circulate fluids to move heat upwards.

Think of it like this – heat pumps move heat from the ground into your household through heat exchange in the ground or water body.

Looking to use another renewable energy source for water heating? Read more on solar water heating here!

How Does Geothermal Cooling Work?

When geothermal heat pumps work in reverse, they move heat from the household into the ground to cool fluids down. Once these fluids have circulated downwards, a cooling effect occurs through heat exchange.

Circulating fluids include anti-freeze chemicals. These fluids are designed to withstand even the coldest temperatures!

In short, geothermal cooling is a much greener alternative to the greenhouse gas emitting conventional air-conditioning systems.

A Geothermal Cooling Unit that can be used in a geothermal cooling system — geothermal heating and cooling.
An example of a Geothermal Cooling Unit that can be used in a geothermal cooling system.
Source: Symbiont Service

How Long Does Geothermal Heating And Cooling Last?

An advantage of ground source heating and cooling is the long-lasting technology.

Research shows that a ground source heat pump’s equipment can last up to half a century – the internal parts last for around 24 years.

The bottom line here is that these systems are long-lasting and reliable. This is a major bonus for those of you wanting to use earth’s energy!

Now that we understand how geothermal heating and cooling systems work let’s break down the costs of this technology.


Types Of Geothermal Heating And Cooling Systems

The four most common household geothermal heating and cooling systems.
The four most common household geothermal heating and cooling systems.
Source: D. Roberts

Each type of geothermal energy system comes with a different price tag. Before we give you the costs, let’s have a quick look at each of these systems.


Closed-Loop Control Systems

The following are examples of closed-loop control systems:

Horizontal Loop System

This system uses two pipes that are buried in a hole with a depth of around 5 ft and a width of 2 ft.

One of the hiccups many people encounter when installing this system is the large surface area it requires. However, there are new methods out there that help combat this issue.

The Slinky Method has become popular in recent years and involves laying shorter coiled pipes into the ground. The coiling reduces the large spaces required for installation.

Vertical System

Vertical systems are deeper but require less horizontal land.

These systems require the drilling of multiple holes around four inches wide and between 100-400 feet deep. Each hole is approximately 20 feet from another, where U-shaped pipes are connected to create a loop system.

The loops are later connected up to a heat pump in your household.

Pond/Lake System

If you have a pond or lake is in the vicinity of your household, you can use a pond/lake system.

In this system, a configuration of pipes runs underground into the water body where they coil at a certain depth.

This will be the most cost-effective option if the body of water meets all of your system’s depth and volume requirements.

Open Loop Systems

These systems are ideal when used with a borehole or water-well — this is even more true in vast areas across the U.S where soil conditions are less than perfect.

These systems circulate water and work through heat exchange directly with the ground.


How Much Does Geothermal Heating And Cooling Cost Per Month?

Geothermal heating and cooling systems are known to have a high upfront cost. This is because the installation process requires qualified professionals.

The good news — once you’ve installed your system, you’ll notice a reduction in your monthly energy bill.


Initial Installation

Let’s hit the ground running with the most expensive phase of a geothermal heating and cooling system — installation!

Important note: Before we begin, we have to impress upon you the importance of using a qualified professional for your system’s installation. You cannot overlook professional help because of the potential impacts on the environment associated with your system, as well as the long-term resilience thereof. What’s more, a qualified installer is vital if you’re considering applying for federal tax incentives relating to renewable energy.

If you’re based in the United States, check out this directory. It’ll help you find qualified installers in your area.

Depending on the type of system you choose, your equipment can cost from $10 000 up to over $40 000.

The basic structure that will make up your system includes three main components:

  • Heat exchanger (sometimes referred to as a loop which comprises circulating fluids)
  • Heat pump with a condensing unit (the part that concentrates heat) 
  • Distribution system to spread the heat or cold
The three main components found in a geothermal heating and cooling system
The three main components found in a geothermal heating and cooling system
Source: North Dakota State University

The components will vary in price depending on the type of system you choose.


Cost Breakdown

Geothermal Energy System TypeEstimated Cost Range
Horizontal System$12 000- $35 000
Vertical System$20 000- $40 000
Open Loop System$10 000- $30 000
Pond System$10 000- $35 000
Estimated Cost for Geothermal Heating Systems

Installation services will bring with them additional costs, but it’s important to note that high-quality installation isn’t something you should slip up on!

These costs can be anything from double to three times the price of the basic equipment. However, the cost will depend on the amount of work necessary to install your system. For example, you’ll pay more if your system requires extensive excavation.

Related Reading: Pros & Cons Of A Geothermal Heat Pump


Operations And Maintenance

You can establish a monthly estimate during the operational phase.

Your ground source heating and cooling pump system will likely cost around $100- $200 in power fees per month. This amount will differ depending on your location and surrounding environment.

This excludes the running of extra pumps or backup heaters that you may need when the temperature drops to the point of it freezing system lines! In this case, the running costs may double.

Maintenance is a non-negotiable factor when it comes to the running of your geothermal heating and cooling system.

Cleaning your air ducts is an example of necessary maintenance. These services cost, on average, $500.

Interested in purchasing a ground source heat pump but unsure about the cost? Check out our article — What Is The Cost Of A Ground Source Heat Pump?

Additional Costs

Additional costs might pop up throughout the pre-installation, installation, or operating phase of your ground pump system.

These may include:

  • Upgrading equipment for suitability: such as wiring in older homes before installation
  • General upgrades: such as higher efficiency or better performing equipment
  • Permits: installation permits can cost anything from $75 to more than $1000, depending on where you live

State Incentives And Credits

Did you know that green energy can come with reduced costs?

Depending on where you live, certain federal tax credits or rebates could greatly reduce your upfront expenditure.

If you live in the United States, you’ll be thrilled to know that governments may offer over 20% tax credit if you have a geothermal system installed when you use a certified system.

If you want to learn more, check out your local and regional state incentives to see what is applicable to your area.

Cost savings, here we come!

If you’re looking to find out the average electricity consumption in your country, have a look at our article — Electricity Consumption (Average Energy Consumption per person)

Final Thoughts

A great takeaway from this article is the choice of technology at your fingertips – geothermal heating and cooling systems come in all shapes and sizes suited to your requirements.

That being said, it’s important to keep in mind the costs involved from installation phase through to the operation of your system.

Whatever your situation, there is a ground source heat pump out there for you!

Charissa Worthmann

Charissa Worthmann

Charissa has a Master’s in Environmental Management (Environmental Science). Her research area of interest and expertise is in the interaction between energy and the environment. She practices as an environmental consultant and has extensive experience working on renewable energy projects.

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Brian

We went all in while building our house in 2013. Only option for energy was electric (relatively inexpensive for all but heating) and propane (very expensive for heating). I decided to eliminate gas from the equation as we all know it’s bad to burn hydrocarbons, but I also believe gas costs will go up even higher at some point. I also wanted to have a large solar PV array and so designed the roof to face south and have no penetrations on that aspect. So we’re 100% electric.

Our 7.95kw solar array generates approximately 10mw a year. Would be more except that the winter months see snow on the panels quite often (but less these days unfortunately). We are grid tied and in an politically reasonable state so the excess energy goes back to the grid and we get full credit for energy produced. The ~10mw of energy is roughly equivalent to $100 a month in energy created. Doesn’t sound like a lot, but as you’ll see, it’s just about all we need with the rest of our energy package…

We also installed a geothermal heating system which consists of three 300′ vertical loops (4″ bores, 1″ pipes sunk and then encased in thermal grout) under the driveway similar to the pictures above. These loops then go into the foundation 6-7′ below the surface and then connect into a Bosch heat pump which has a redundant 10kw resistive backup heater. Not sure it has ever run. Our system is forced air which has its positives and negatives. Positives include much cheaper installation since it’s ducts instead of in floor radiant. Also heating while much slower than traditional gas forced heat, is still much faster to recover/come up to temp than radiant. Also no chance of leaks from water pipes covering every square foot in the floors. Forced air also requires air filters but that is a positive in that the air is filtered and circulated frequently. Negatives are that we get the forced air noise.

The system also consists of a desuperheater which takes waste heat from the heat pump and circulates it in into a storage only water heater tank. This preheats the water passively which then takes less energy to heat up to domestic temps for hot water. Not sure how efficient or economical this system is, but I thought the idea behind a desuperheater sounded good and it cost little more than the storage tank to implement so..

Now for the most important bits. The solar PV array cost ~$28k in 2014. The entire geothermal system which included all the HVAC sheet metal and vents, bathroom fans (unrelated to geo but HVAC and thus fed tax rebate eligible with system!), the Bosch heat pump, Honeywell smart thermostat, 2 top of the line Rheem water heaters/tanks and the 3 drilled wells and all 1800′ of tubing cost about $42k. So $70k for both. BUT, we got a 30% federal tax credit which put $21k into our tax refund in 2015. We also got about $5k in credit from our energy provider as an incentive to build renewable energy.

House is 3,000 sf and sits at 10,000 feet in the relatively cold Rockies. Winter is a good 6 months and we have no need for cooling in the summer, though it would be interesting to run the heat pump in the summer which brings cold ~50 degree earth temps to the surface for nearly free air conditioning. This is an often overlooked benefit of geothermal/heat pump, especially in hot areas. It works for both heating and cooling in one system. With the 10mw of electricity generated per year, our average yearly cost of energy is about $500. We have bills for 2 months (Jan/Feb) when our stored electricity bank exhausts. Nearby neighbors often have $500 or more energy bills per month in the winter so I would say we are doing quite well on the energy front. I’ve not done the payback analysis exactly, but I would estimate 10-15 years. But once it’s paid off it will be free for the life of the system which is ~25 for solar PV and 25-50 for the geothermal. Contrast this to traditional HVAC which needs to be replaced about every 10 years and also requires the owner to pay month after month for energy.

Geothermal and solar PV should be mandated with all new construction IMO. If that were to be the case, costs would plunge with economies of scale as well as competition. As it is today, costs remain too high for most, even though the costs can be rolled into mortgages and money saved every month thereafter.

Kyle Browning

Thanks for sharing Brian. Sounds like you have one great setup at home!

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