All You Need to Know About Home Geothermal Heating & Cooling

Have you heard of home geothermal heating and cooling? It’s an HVAC system that can save homeowners serious money on utility bills.

Unfortunately, many people have never heard of home geothermal, or they don’t understand it. A lot of people think it has something to do with capturing heat from volcanoes or geysers.

That would be pretty tricky to pull off for most homeowners, and it would seriously limit the number of people who could take advantage of geothermal energy.

Thankfully, you don’t have to live anywhere near an active volcano to have an effective, money-saving home geothermal system installed.

Home geothermal heating and cooling is actually fairly simple. Here’s how it works.

How does home geothermal energy work?

The temperature of the earth 10 feet below surface level is a constant 55 degrees Fahrenheit year-round.

When the air outside your home is below freezing, just 10 feet below the snow-covered ground it’s still 55 degrees. Or when summer brings 96-degree weather, the earth beneath your house keeps steady at 55 degrees.

You have probably experienced this phenomenon at home without even realizing it. When you go into your basement on a hot day, it’s nice and cool down there because the earth on the other side of your foundation is, you guessed it, 55 degrees.

In the winter, even an unheated basement stays relatively warm because of that consistent 55-degree insulation from the surrounding earth.

Geothermal systems, such as the Dandelion Energy system, take advantage of this naturally occurring constant. They harness the steady temperature surrounding any home to heat or cool it as needed.

Although it’s referred to as geothermal energy, geothermal and other home geothermal systems don’t make electricity. They use the sustained temperature of the ground to heat or cool your home.

The function of a ground loop system is to absorb heat energy (BTUs) from the earth so that it can be transferred to a heat pump and efficiently converted into warmth for your home. While that means you can’t use ground loops to heat your driveway, it also means that once buried, your geothermal system won’t mess with your lawn and garden. In fact, Dandelion’s ground loops systems are built to last for over fifty years and should require no maintenance.

The number of BTUs necessary to heat your home will vary based on a few diffener factors: house size, insulation, and the conditions of the soil on your property. Accordingly, it’s important that the size and number of ground loops installed are up to your home’s needs. Many homes require more than one ground loop, with vertical loops that means boring more wells at least twenty feet apart to absorb enough BTUs to power your heat pump. Dandelion uses proprietary software technology to accurately design a ground loop system that will fit your home and keep your family warm.

Components of a geothermal system

There are three components to just about every heating system: the fuel, the furnace or boiler, and the delivery system. For instance, if your home relies on oil to keep warm, you’ll recognize the fuel as oil that usually lives in some rusty tanks in your basement, that fuel goes into the furnace where it’s burned to generate heat through combustion, that heat will then be distributed throughout your house through either radiators or an HVAC system.

Geothermal also has three roughly analogous components, but the first two are what make geothermal so different from traditional heating systems: ground loops, an underground system that taps into the thermal energy under your lawn; and a heat pump powered by electricity, that moves liquid through those pipes to harness that energy and efficiently convert it to a higher temperature. Finally, an HVAC system distributes that heat to keep your family warm. Geothermal heating systems can also be referred to as ground source heat pumps or GSHPs precisely because it sources underground heat using ground loops in order to power a heat pump.

A Dandelion geothermal system uses vertical ground loops, where pipes are installed anywhere from 200-500 straight down into the earth. Vertical ground loops are installed using well-boring equipment and trenched back into the house to connect to a heat pump. Those pipes are made of a highly conductive, and super durable high-density polyethylene material and circulate a mixture of water and propylene glycol, a food-grade antifreeze, that absorb the ground’s temperature.

Now that we know how geothermal heating pulls heat energy from the earth, we’re still left with the question how we can heat our homes with it. After all, 55 degrees might sound better than the temperature outside on a January evening, it’s few people’s idea of cozy conditions. That’s where the heat pump comes in. Heat pumps are devices powered by electricity that gather heat energy from one place and transfer it to another. Even if you’ve even never heard of a heat pump before, you probably utilize the technology everyday: refrigerators work by transferring heat from inside of your fridge to the outside. In terms of heating your home, there are air source heat pumps (ASHPs) and ground source heat pumps (GSHPs).

A ground source heat pump mechanically circulates that thermally conductive liquid solution through the ground loops. After absorbing the ground’s thermal energy, that solution then goes back into the heat pump and exchanges its heat energy with liquid refrigerant inside the heat pump. That refrigerant is then turned into a vapor and compressed. The act of compressing that vapor increases its temperature. Once that vapor is hot enough, it enters a heat exchanger which transfers that heat to the air. That warm air is then circulated using your home’s standard HVAC ductwork.

Differences between geothermal systems

Though many geothermal systems are similar, there are differences between them. Some used a closed or open loop system, pond loops, or slinky coil ground loops.

There are pros and cons to the various loop configurations for geothermal home heating. Dandelion engineers use closed-loop systems. They see them as the most efficient and safest option for homeowners.

When a Dandelion system is installed, closed-loop pipes with a water solution are buried in the ground beneath your home. “Closed loop” means the pipes are contained only to your house. They aren’t connected to a larger infrastructure, and won’t interact with any fluid outside your system.

As this water circulates through Dandelion’s pipes, the water solution within the pipes changes temperature. In the wintertime, this 55-degree solution is warmer than the outside air.

Dandelion’s system pulls this warm solution through the pipes and uses a heat pump to warm the air from your home. This allows you to adjust the air in your home to whatever temperature you desire.

The same principle works in reverse in the summertime when Dandelion’s system uses the temperature of the ground to cool the air in your house.

It doesn’t matter if it’s a crisp 65 degrees or a toasty 88 degrees outside. Your geothermal system makes it easy to get comfortable at home.

Is geothermal really worth it?

Installation of a Dandelion system can save homeowners up to 50% on their heating and cooling bills every month. It’s a smart investment that leads to long-term savings, all while keeping your home comfortable all year round.

In the US, heating and cooling residential and commercial buildings contribute about 11 percent of the nation’s total carbon dioxide emissions.

Home geothermal systems create zero carbon emissions. Over the course of a year, using one Dandelion Energy system reduces enough carbon emissions to equal removing two cars from the road.

These wonders of engineering are also safer for your home than traditional heating and cooling systems. With Dandelion geothermal, there’s no risk of explosion or carbon monoxide leaks to endanger your family.

Geothermal heating and cooling cost

While the price of electricity, oil, or natural gas fluctuates, the cost of operating a geothermal system will stay pretty much the same. The electricity costs of a geothermal system are low and seldom vary from month to month.

Despite their many advantages, installing a conventional geothermal system for a typical home used to cost up to $50,000 or more.

However, the engineers at Dandelion, a spinoff from a Google X project, set out to drive those costs down. Thanks to their ingenuity, geothermal systems are now affordable to more homeowners.

Instead of using large drill rigs like those used to bore artesian wells, Dandelion began experimenting with smaller, more efficient drills that make one or two deep holes just a few inches wide.

The company then installs U-shaped pipes into these holes. This innovation takes up less space and creates less of a disturbance in the back yards of Dandelion customers.

Using the new equipment, installation of the ground loop pipes can be completed in days instead of a weeks, saving customers time and money.