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October 19, 2023

How Heat Pumps Work

A repair man completes routine maintenance on a ground source heat pump

Heat pumps are the unsung heroes of Canadian homes, keeping them cozy during chilly winters and comfortably cool throughout the warm summer. However, many people are unaware of how heat pumps work.

How does a ductless heat pump work? How does an air source heat pump work? How does a geothermal heat pump work? These are all common questions we receive from our clients.

The good news is that we’re here to help explain the inner workings of heat pumps, including specialized varieties. Ultimately, learning more about heat pumps will help you decide if one is right for your home.

Ready? Let’s get started!

What Are Heat Pumps?

Before we explain how heat pumps work, let’s first define what heat pumps are.

Heat pumps are mechanical systems that provide both heating and cooling in a single unit. They don’t generate heat directly, instead, they transfer heat from one area to another. They are known to be energy-efficient and are often powered by renewable energy sources, making them a top choice for people seeking cleaner and greener solutions.

The different types of heat pumps include:

  • Air-Source Heat Pumps (ASHP)
  • Ground-Source Heat Pumps (GSHP)
  • Geothermal Heat Pumps
  • Ductless Mini-Split Heat Pumps

To keep it simple, we want you to remember that while heat pump models vary in terms of heat sources and methods of heat exchange, the core principle—that they transfer heat energy from one place to another—will always stay the same.

Now, let’s break heat pumps down in detail:

The outdoor unit of a heat pump working in winter Image Source: Canva

The Components of a Heat Pump System

If you want to better understand how heat pumps work, it can be helpful to learn about their different components. They are as follows: 

  • Outdoor Unit: Air-source heat pumps have an outdoor unit that contains a set of coils (known as the condenser and evaporator) and a fan that blows outside air over the rings to begin heat exchange. 
  • Heat Exchanger: Ground and water-source heat pumps rely on an underground or submerged heat exchanger loop. It’s where the refrigerant flows and absorbs heat.
  • Air Handler: Indoor units also contain a set of coils (condenser and evaporator) and a fan that distributes the cool or warm air throughout the ducts.
  • Refrigerant: This substance absorbs and rejects heat as it flows throughout the heat pump system. 
  • Compressor: Manipulates the refrigerant’s temperature and pressurizes it to move around the system.
  • Reversing Valve: This switch reverses the refrigerant flow and swaps the operating system, changing it from heating to cooling and vice versa.
  • Expansion Valve: This metering device manages the flow of refrigerant and controls its pressure and temperature.
  • Condenser Coil: It releases heat into the air. 
  • Evaporator Coil: It collects heat from the air.

→ Note: The basic parts of a heat pump system are generally the same regardless of the type used, but there can be variations and differences in their design and operations. 

The Refrigeration Cycle & Heat Transfer Process

The refrigeration cycle generally remains the same across different heat pump systems. Here’s how this process happens in an air-source heat pump:

  • When the thermostat changes, the expansion valve pumps a liquid refrigerant through its coils.
  • The fan in the outdoor unit pulls air over the coils; these start to absorb heat from the air and expand as hot vapour.
  • The vapour moves through the compressor, increasing its pressure and temperature before flowing into the indoor unit’s coils.
  • The heat pump’s blower then pumps the heat through the air ducts to distribute it throughout your home.

Ground and Water Heat Pumps

Ground and water heat pumps work the same as air-source types. However, instead of having outdoor units, they have a series of pipes found underground or submerged in water. These devices also pump a liquid refrigerant or a cold water anti-freeze mix and are used to gather heat from the earth or a water source.

Ductless Heat Pumps

You may now be wondering “How does a ductless heat pump work?” It’s pretty similar, except they have individual indoor units serving specific zones.

Geothermal Heat Pumps

Now, how does a geothermal heat pump work? These can be understood as a subset of ground-source heat pumps, however, they use the stable temperature of the earth’s ground as the heat source or heat sink.

A woman adjusting the settings on her thermostat

Heating and Cooling Modes

When learning how heat pumps work, something else to understand is their ability to quickly switch between heating and cooling modes.

In heating mode, the heat pump absorbs heat from the outdoor environment or the ground, raises its temperature, and releases it indoors to warm your home. The process is reversed in cooling mode as the heat pump extracts heat from your indoor air and then releases it outdoors to cool your home.

This is made possible by the reversing valve, which directs the flow of refrigerant and changes the system’s operating mode as needed. So, whether you’re staying cozy in winter or enjoying a refreshingly cool environment in summer, your heat pump is hard at work.

Trust LG Home Comfort for Your Heat Pump Needs

We heard your questions—“How does a ductless heat pump work?” “How does an air-source heat pump work?” “How does a geothermal heat pump work?” “How does a mini split heat pump work?”—and hope we’ve answered them!

Now that you know how heat pumps work, the next step is buying one and having it installed in your home. The installation can be a serious job, which is why you should trust the experts at LG Home Comfort!

You can count on us for:

  • Expert Guidance
  • Quality Installation
  • Reliable Repairs
  • Exceptional Service

Contact us today for a quote or to learn more about our services!

Terms and Conditions

  • Once an initial service has been completed, the customer will be on a one-year commitment
  • After the initial 12 months, the contract will be renewed on a month-to-month cadence
  • If a service is completed for the next year, it automatically renews the commitment for an additional year
  • Customers can cancel at any time after the 12-month initial commitment as long as the following year’s service has not been completed.
  • Customers need to provide 30 days written notice in order to cancel their plan