What Is a Heat Pump and How Does It Work?

What Is a Heat Pump and How Does It Work?

Indoor temperature control enhances homes, creating more comfortable and enjoyable spaces. In the sweltering summertime, ventilating cool air throughout your home creates an ideal and healthy indoor atmosphere. In winter, heat produces a cozy ambiance and comfortable room temperatures to combat the frigid outdoors. Indoor heating and cooling optimizes your home and experience.

With the rise of technological advancements, heating and cooling units come in numerous forms. Between the selection of furnaces, fireplaces, fans, and air conditioners, one influential heating and cooling system is the heat pump. So, what is a heat pump, and how does it work?

What Is a Heat Pump?

Heat pumps operate through thermal transportation, cycling indoor and outdoor air through an intricate system. Unlike other temperature control technology, heat pumps offer both heating and cooling options. They can reverse their operations and switch between heating and cooling with the simple press of a button. Heat pumps provide a one-stop shop for indoor temperature control, eliminating the need for various heating and cooling mechanisms around the home. They offer an efficient way to monitor indoor temperatures.

Heat Pump Components

Heat pump systems consist of various important components. Each section plays an integral role in the system's functionality and success. Here are the major parts of a heat pump that factor into the system's operations.

Outdoor Unit and Compressor

Since heat pumps primarily function by transferring and transforming indoor and outdoor thermal energy, they consist of an indoor and outdoor unit. The outdoor unit releases unwanted air and heat energy from the indoors to the outdoors. It also takes in thermal energy from your home's exterior and uses that energy and air for its heating capabilities, preserving your interior's existing heat and adding more to its collection. The outdoor unit also consists of a compressor, which functions in tandem with a refrigerant. It applies high pressure to the refrigerant, heating it and compressing it into high-pressure gas.

Indoor Unit

The indoor unit typically comes in the form of a vent or AC. It releases the heated or cooled air into your home with a built-in fan. They also take in the room's current air and filter out large particles like dust. The indoor unit functions as the main ventilator component, while the outdoor counterpart does the bulk of the heating and cooling magic behind the scenes.

Refrigerant Coils

Refrigerants mainly operate as a means to transfer thermal energy between indoor and outdoor units. They carry the energy as a liquid or gas depending on the compressor and evaporators in the system. They replace the need for large bulky ductwork, allowing the heat transfer to occur through slim pipe coils.

Reverse and Expansion Valves

Reversal and expansion valves function similarly to the compressor. They also do a majority of the transformation within the system. The expansion and reverse valves also act as control cogs. As its name suggests, the reverse valve dictates the reversal of operations. It switches the flow of refrigerants and changes the operation of the heat pump between cooling and heating properties. The expansion valve oversees the amount of heat and cool thermal energy passing through the refrigerants, transforming the temperature you receive.

How Does a Heat Pump Work?

Heat pumps work closely with pre-existing air. They pump heat energy from collected air through a system that heats and cools the energy and emits it into your home. In cooling mode, the thermal energy gets collected from the interior unit. The energy then goes through the refrigerants, compressor, and expansion valve back to the indoor unit, where a fan blows cool air out to your room. In heating circumstances, the reverse valve reverses the system. The thermal energy gets collected from the outdoors, preserving indoor heat energy and adding more to it to achieve your desired indoor atmosphere.

Different Types of Heat Pumps

Heat pumps come in numerous types and forms. The main components that differ include the systems' placement, collected energy source, and added attributes, such as vents, ducts, and split zones.


The most common type of heat pump system is air-to-air. As implied, air-to-air systems collect and use heat energy from the air. They then release that energy back into your home as hot or cold air.

Water Source

Water-based heat pumps generate heat in a way that’s similar to boilers. They use pumped hot water, circulating through coils, to heat the surrounding air. Compared to boiler heaters, water source heat pumps use the AC unit or indoor component of their system to process the hot water and blow out the heated air into your home.

Geothermal Heat

Geothermal heat pumps work similarly to air-to-air units but source their heat from the ground and release unwanted heat energy underground instead of to your home's exterior. Geothermal energy is popular in numerous places due to its positive environmental contributions. Since underground thermal energy maintains a steady temperature supply, geothermal energy systems offer more efficiency.

Hybrid Pumps

Hybrid pumps come in various combinations. On top of differing in how they collect heat energy, they also vary in their energy input. Popular hybrids include:

  • Geothermal and air-to-air combos
  • Heat pump and boiler hybrid
  • Solar and geothermal
  • Air-to-air and fossil fuel

Ducted, Ductless, and Multi-Zone Units

There are numerous pros and cons between ducted and ductless HVACs. Mini split heat pumps come in both variations. However, their ducted systems vary from typical ductwork. The main purpose of a ducted mini split is to split the air into multiple zones. Each zone connects to a single heat pump and temperature control mechanism, saving the need for multiple units. Plus, ducted mini splits use compact vents and ductwork, minimizing size and required space.

Heat pumps without ducts still offer zoning capabilities and account for individual room control and the need for multiple indoor units. Ducted or ductless multi-zone mini split AC systems typically function on air-to-air source mechanics but ensure multiple rooms within a home reap the benefits of a heat pump.

When To Use a Heat Pump

Heat pumps make great home additions in areas that experience multiple seasons. Their dual-functioning system of heating and cooling fits the needs of those exposed to hot and cold forecasts. On top of providing the most efficient temperature control solution for those with seasons, heat pumps also benefit those looking for efficient, eco-friendly, and multifaceted heating and cooling. They provide a one-stop shop for temperature needs, minimizing your need to purchase additional heating and cooling solutions. Consequently, they save more energy and overall costs of home improvements.

Knowing what a heat pump is and how it works gives you a greater range of temperature control options to add to your home or office. These economical, efficient, and multifaceted heating and cooling systems offer multiple benefits for numerous people and homes. Investing in a heat pump helps you maintain adequate indoor temperatures and create a comfortable indoor living and work space to enjoy year-round.

What Is a Heat Pump and How Does It Work?