How a Geothermal HVAC System Works

Looking for a more energy efficient option to keep your home at a uniform temperature throughout the year? The indoor air quality professionals at Berkeley can slash your AC bills by 60, 70, or even 80 percent a year with a state-of-the-art geothermal HVAC system. You could save thousands of dollars annually without sacrificing your family’s comfort.

Using the Earth’s Constant Temperature

Most people are familiar with geothermal energy through utility-scale operations that generate electricity for tens or even hundreds of thousands of homes. However, homeowners can utilize the planet’s near-constant underground temperature to keep their homes the same temperature all year-round.

When you walk outside, the temperature can fluctuate by up to 150 degrees depending on where you live. Underground, it’s a different story. A mere 20 feet below the surface, the ground stays between 50 and 60 degrees Fahrenheit because it’s insulated from day-to-day weather changes.

A traditional air conditioner will have to work harder on hotter days not only because the building absorbs more heat but because the air conditioner transfers heat less efficiently. Geothermal systems are so efficient in part because they can transfer heat at a uniform rate regardless of what the weather is like on a given day.

Furthermore, geothermal HVAC systems work equally well in summer and winter. During the summer months, the geothermal system pumps heat from the home to the ground, and during the winter, the system pumps heat from the ground to the home.

Types of Earth Loops

At the heart of every geothermal HVAC system is what is called a ground or earth loop — essentially a number of looping pipes that carry a mixture of water and ethanol out into the ground surrounding your home and back again. Because there is quite a bit of trenching or drilling involved, geothermal systems do have a higher upfront cost, but think of it as an investment that will save you thousands in energy costs over the system’s lifespan. Just how efficient are they? National Geographic estimates that a geothermal system uses just “one unit of electricity to move up to five units of heating or cooling.”

That water can transfer heat either to or from your home depending on whether you need heating or cooling at a given moment. Because it does both, there’s no need for a separate furnace or air conditioner to supplement the system. Ethanol is added simply to help prevent freezing in the pipes, and most systems use polyethylene pipes, which can easily last for generations. Even if your pump needs to be replaced, the ground loop should remain in good working order for 40 or 50 years.

Horizontal ground loops are most common in homes that have large yards. They’re cost-effective because they only require a shallow trench to be dug in your yard, but there needs to be sufficient space to lay up to 400 feet of pipe.

Vertical ground loops are more common in urban and suburban settings because instead of being laid out horizontally, they go straight down several hundred feet. Drilling can add to the system’s cost, but if space is a concern, a vertical loop is the way to go.

Have a pond or lake on your property? A body of water provides excellent thermal conductivity and requires far less digging, but the pond has to meet minimum size and depth requirements.

Benefits of a Geothermal HVAC System

Geothermal heating and cooling systems are the single most energy efficient option for keeping your home comfortable throughout the year. While these systems do cost more upfront, those costs will become net savings within just a few years, and because they can last for decades, a geothermal system will last as long as two or three conventional forced air HVAC systems. The coolant pump is also very quiet, so you won’t have to deal with any noisy compressors.

Interested in substantially reducing your utility bills while keeping your home comfortable? Call the Berkeley geothermal experts at 843-277-6030 to request more information or a free quote.