November 9, 2022
Do Geothermal Heat Pumps Rely on Gas?
Here in Saint Louis, MO, geothermal heat pumps offer an environmentally friendly and economical HVAC option for homeowners and businesses. Since the technology’s relatively new to the area, however, plenty of people don’t quite understand how it works.
At Scott-Lee Heating Company, we field questions about geothermal heat pumps all the time. One of the most common among them is whether or not geothermal heat pumps use gas to operate. To answer that question, here’s an overview of how geothermal heat pumps work that explains exactly how they heat and cool the buildings they serve.
What Powers a Geothermal Heat Pump?
To get right to the point, geothermal heat pumps don’t use gas. They operate exclusively on electricity. However, they don’t use the electricity itself to heat or cool a building. This is the point that tends to confuse people who have no experience with geothermal technology, and for good reason.
Traditional heating and cooling methods are energy-intensive. Gas or oil-powered furnaces burn fossil fuels to generate heat. Most of them also rely on electricity to power the fans that circulate the heated air around your home.
Conventional air conditioning systems also use electricity to power compressors and blowers. The compressor is what makes an air conditioner’s refrigerant cold enough to cool your home’s air as it passes through the system. And like a furnace, the blower motor is what moves the air throughout your home.
Geothermal heat pumps also rely on blower motors that run on electricity. However, that’s where the similarity with conventional heating and cooling systems ends. They generate hot and cold air for a building by exploiting the stable temperatures found just below the surface of the ground or underwater. That’s the secret to their efficiency and low operating costs.
How Geothermal Heat Pumps Work
Geothermal heat pumps, unlike conventional HVAC systems, have a series of outdoor pipes that run either underground or under the waterline of a nearby lake or pond. The pipes serve as heat exchangers for the system. The reason for that is as ingenious as it is convenient. It’s because temperatures below a certain depth underground or underwater stay stable all year round. Depending on the region, you’ll find temperatures between 45 and 75 degrees Fahrenheit underground no matter the time of year.
That means the temperature there will be warmer than the outside air in the winter and cooler than the outside air in the summer. Geothermal heat pumps circulate a refrigerant through their underground pipes. In the winter, the refrigerant absorbs underground heat to carry back to the system, where it heats the air for use indoors. In the summer, the opposite happens, as the refrigerant carries heat from indoors and exchanges it for the cooler underground temperature.
Understanding the Efficiency of Geothermal Heat Pumps
Since geothermal heat pumps don’t use electricity or fossil fuels to generate warm or cold air, they cost far less to operate than conventional systems. They’re so efficient that it’s difficult to even compare them to gas, oil, and electric-powered HVAC systems. For example, a modern high-efficiency gas furnace operates at around 95% efficiency. That means you get about .95 units of heat for every 1 unit of gas you burn.
By comparison, a geothermal heat pump can generate as much as 4 units of heat for every unit of electricity they consume. That’s an astonishing 400% efficiency rate! Geothermal heat pumps can do this because they’re capturing heat from the environment instead of generating it through traditional means.
In the summer, geothermal heat pumps also operate more efficiently than conventional air conditioning. Air conditioners receive energy efficiency ratings on a scale called SEER. The higher the SEER rating, the more efficient the unit. The average central HVAC system installed today has a SEER rating of 16. A comparable geothermal heat pump might have a SEER rating as high as 30, making it almost twice as energy efficient.
The Types of Geothermal Heat Pumps
Since no two homes or buildings are alike, there are four different types of geothermal heat pump systems to suit different needs. They offer multiple installation options depending on the amount of space you have to work with or the features of the property around the building you’re trying to cool. The four types of geothermal heat pump systems are:
- Closed-loop geothermal systems
- Open-loop geothermal systems
- Horizontal geothermal systems
- Vertical geothermal systems
Closed-loop systems circulate refrigerant through underground pipes or pipes submerged in the water of a nearby lake or pond. Open-loop systems, by comparison, use well water or water from a nearby source in place of refrigerant. They’re often used in locations that already rely on well water and can even produce hot water in place of a conventional water heater.
Horizontal loop systems are quite common in residential areas because it’s cost-effective and doesn’t require much room. Horizontal loop systems have underground pipes that are at least 4 feet deep. Vertical loop systems are similar but more commonly used for large commercial buildings. They rely on pipe loops running through holes that may go as deep as 400 feet below ground level.
Cost Considerations of Geothermal Heat Pumps
The only area where geothermal heat pumps don’t outperform conventional HVAC systems is in their initial cost. They do tend to cost more to install because you need to dig trenches or drill holes for the heat exchanger pipes the system needs to operate. According to the US Department of Energy, however, the average geothermal system pays for itself in energy savings within five to 10 years.
When you consider that a geothermal heat pump can last for up to 25 years, that means you’ll enjoy many years of savings after the system pays you back for your installation costs. Plus, the ground loops used by geothermal heat pumps can last up to 50 years, so you’ll be able to replace the above-ground parts of a geothermal heat pump system at a much lower cost if you need to in the future.
Trust the Geothermal Experts
Now you know that geothermal heat pumps don’t use gas. You also know how they work and the many benefits they come with for those who rely on them. If you like what you’ve read and want to know if a geothermal heat pump is a good option for your home or business, Scott-Lee Heating Company is the right place to turn.
We’ve served the Saint Louis area since 1978, providing a variety of services, including comprehensive HVAC services, geothermal system design and installation, new construction heating and cooling installation, indoor air quality solutions, and metalwork. In other words, there’s no residential heating or cooling task we can’t handle. We’ve even won the highly sought-after Dave Lennox Award, given for providing exemplary customer service and outstanding business practices for 26 out of the 40 years it’s existed. You won’t find any other HVAC company that can say that.
So, if you’d like to discuss a new geothermal heat pump for your home or business, contact Scott-Lee Heating Company today!