Ground-Source Heat Pumps
Ground-source heat pumps move heat in and out of the ground through pipes buried underground.
It takes far less energy to move heat than it does to create heat, which means ground source heat pumps are very efficient. Typically, a fossil fuel heating system is 80-90% efficient, wasting 10-20% of every dollar you spend on oil, gas, or propane. A ground-source heat pump can be 350-500% efficient, providing 3.5-5 units of heat for every unit of electricity you pay for.
Because the ground is more stable in temperature year-round than the outdoor air, ground source heat pumps are more efficient than air-source heat pumps and air conditioners at heating and cooling, making ground source heat pumps the most efficient heating and cooling technology available.
Program Installer
Achieve Renewable Energy participated in the MetroWest Solar + Clean Heat Challenge in 2021 and contracts with 15 residents.
Achieve’s staff has a proven track record designing and installing geothermal systems in New England. They are the only design and installation company in New England with staff certified by the International Ground Source Heat Pump Association as both a Certified Geoexchange Designer and Certified Geothermal Inspector.
How Ground-Source Heat Pumps Work
Also known as a geothermal heat pump, a ground-source heat pump exchanges heat through pipes buried in the ground either in vertical boreholes, long narrow trenches, or an existing groundwater source.
In the winter, the system absorbs the abundant, renewable heat in the ground to heat your home.
In the summer, when the air is warmer than the ground, it uses the cooler temperature of the earth to reduce the temperature of the air in your home.
Ground-source heat pumps most often pair with ductwork, although there are options available for homes with hot-water based heating systems.
Types of Ground-Source Heat Pumps
Ground-source heat pumps consist of three parts: ductwork or piping throughout a home or building, the heat pump unit, and a system of tubes called a loop that is buried in the ground near a building. There are two types of loop systems: “closed” and “open” loops.
Closed-loop systems:
Closed-loop systems use a continuous loop of buried piping. In New England, most closed-loop systems are installed in vertical configurations, in which the ground loop is run through multiple boreholes that are drilled several hundred feet deep.
Open-loop systems:
Open-loop systems can be used where there is a source of clean, readily available groundwater on the property from a well. Open-loop systems are typically cheaper to install, and they are more efficient due to the more consistent year-round temperature of groundwater. Open-loop systems may require additional permitting or environmental review.
Learn More About Ground-Source Heat Pumps
Frequently Asked Questions About Ground-Source Heat Pumps
+ Are ground-source heat pumps effective in cold climates?
Yes, ground-source heat pumps work well in cold winter climates. While we might experience seasonal temperature changes above ground, the earth below the frost line is unaffected at 50 degrees Fahrenheit.
+ Will a ground-source heat pump save me money?
Yes, but the return on investment in a ground-source heat pump can take many years. Ground-source heat pumps are the most efficient system available, but they cost more upfront to install than air-source heat pumps. They are a better choice for homeowners who plan to stay in their homes and have time to benefit from all of the potential energy savings offered by a ground-source system than they may be for homeowners who are planning to move after a few years.
+ How are ground-source heat pump systems installed?
Most of the ground-source heat pump installation is underground. Inside the house, the heat pump units are about the same size as a traditional heating and cooling unit.
Most units are easy to install, especially when they are replacing another forced-air system as a retrofit. If your home does not have an existing air distribution system, your installer will need to add ductwork. Your installer can assess the cost of any ductwork if needed.
+ Do ground-source heat pumps require much maintenance?
Ground-source heat pump systems can be virtually maintenance-free. When installed properly, the buried ground heat exchanger can last for generations. The other half of the operation—the unit’s fan, compressor, and pump—is housed indoors and protected from the harsh weather conditions. Usually, periodic checks and filter changes are the only required maintenance.
+ What’s the difference between a ground-source heat pump and an air-source heat pump?
A ground-source heat pump extracts heat from the ground, just a few feet below the frost line. An air-source heat pump extracts heat from the outside air.
+ Where can I get more information about ground-source heat pumps?
Check out the MassCEC for information on ground-source heat pumps.
Energy Efficiency Matters Too
Making your home more energy-efficient will help you save money on utility bills and reduce greenhouse gas emissions, regardless of your power source or the fuel used by your heating system.
Adding insulation, sealing air leaks, and switching to LED lightbulbs are all great ways to reduce energy costs and make your home more comfortable. These steps can also enable savings on other upgrades, like solar energy or clean heating and cooling systems. For example, a less leaky, better-insulated home will require smaller (and therefore less expensive) heating and cooling units, saving you money up front and on operating costs.
Mass Save provides guidance and incentives to improve your home’s energy efficiency. We recommend scheduling a free home energy assessment with Mass Save to start your clean energy home journey!
For Framingham Residents:
Join in the city’s program to save energy and cut costs through Framingham Saves Energy. Schedule your no-cost energy assessment through framinghamsaves.org.
Images and information on technology provided by MassCEC