What Is a Heat Pump? How It Works and Types Explained

A heat pump(opens in new tab) is an energy-efficient heating and cooling system that moves heat between the indoors and outdoors, rather than generating heat through combustion. During the winter, a heat pump extracts ambient thermal energy from the outside air, ground, or water and transfers it inside your home. In the summer, it reverses this process, acting exactly like a central air conditioner by pulling heat out of your indoor air and exhausting it outside.

Because heat pumps transfer existing heat rather than burning fossil fuels like oil or natural gas, they are incredibly efficient. According to the U.S. Department of Energy (DOE), today’s heat pumps can reduce your electricity use for heating by up to 50 percent compared to electric resistance heating like furnaces or baseboard heaters.

Furthermore, because a heat pump provides both heating and cooling capabilities in one unit, you only have one system to maintain year-round.

How Does a Heat Pump Work?

To understand how a heat pump works, it helps to think of your kitchen refrigerator. A refrigerator cools your food by extracting the heat from inside the box and pumping it out into your kitchen. A heat pump uses this exact same thermodynamic process to warm or cool your home.

The system relies on a few key components:

• Refrigerant: A chemical compound that absorbs and releases heat as it shifts between liquid and gas states.

• Compressor: Pressurizes the refrigerant to move it through the system and increase its temperature.

• Coils: The outdoor and indoor coils act as condensers and evaporators to release or absorb heat.

• Reversing Valve: This crucial valve reverses the flow of the refrigerant, allowing the system to seamlessly switch between heating and cooling modes.

Even on freezing winter days, there is still a significant amount of heat energy in the outdoor air. The refrigerant absorbs this ambient heat, gets compressed to a high temperature, and transfers that warmth into your home’s ductwork or air handlers.

The 3 Types of Heat Pumps

Depending on your property layout and budget, there are three main categories of heat pumps to choose from:

1. Air-Source Heat Pumps (ASHPs)

Air-source heat pumps are the most common and popular residential option, transferring heat directly between your home and the outside air.

While older models struggled in freezing temperatures, modern Cold-Climate Air-Source Heat Pumps are engineered specifically for harsh New England winters. Using variable-speed inverter compressors, these advanced units can provide reliable, efficient heat even when temperatures drop well below zero.

Many local New Hampshire homeowners also opt for a dual-fuel setup. This pairs an air-source heat pump with an existing gas or oil furnace(opens in new tab). The heat pump runs during mild weather for maximum efficiency, and the furnace automatically kicks on only during the most extreme cold snaps. Air-source technology is also the foundation of ductless mini-split systems(opens in new tab), which are perfect for homes without traditional ductwork.

2. Water-Source Heat Pumps (WSHPs)

Water-source heat pumps operate similarly to air-source models, but they extract and dissipate heat using a body of water instead of the air. A series of submerged pipes cycle a liquid solution to collect heat from a nearby pond, lake, or deep well. Because water holds temperatures more consistently than air, these systems are highly efficient and can significantly reduce your household carbon footprint.

3. Geothermal Heat Pumps (GHPs)

Also known as ground-source heat pumps, geothermal systems use a network of pipes buried underground. Because the earth’s temperature just a few feet below the frost line remains a relatively constant 45 to 75 degrees year-round, geothermal systems offer unparalleled reliability and efficiency.

While geothermal heat pumps cost more upfront due to the excavation required, they pay off massively with long-term monthly energy savings and incredibly long lifespans. Additionally, geothermal installations frequently qualify for significant federal energy tax credits.

Heat Pump Maintenance and Upkeep

Because a heat pump works double-duty to heat and cool your home all year, regular upkeep is essential. The DOE recommends scheduling a professional maintenance visit(opens in new tab) at least once a year.

During a tune-up, your local HVAC technician will check for leaky ductwork that causes energy loss, inspect electrical connections, and verify refrigerant levels. Running a heat pump with low refrigerant not only damages the compressor but can also negatively impact your indoor air quality(opens in new tab) and system efficiency.

Is a Heat Pump Right for Your Home?

Whether you want to reduce your carbon footprint, lower your monthly utility bills, or replace an aging air conditioner, a heat pump is one of the smartest investments you can make in your home’s comfort.

Our team is pleased to bring the finest, most advanced heating and cooling options to our local community. If you have questions about which heat pump system is best for your property, give our home comfort experts a call today or request an estimate online(opens in new tab) to get started!