What is a Heat Pump System & How Does It Work?

March 15, 2022

A heat pump is a home appliance that extracts heat from an outside source and then moves it inside to accommodate heating or cooling needs. Since it moves heat rather than generating it, it’s a highly efficient, cost-effective and environmentally-friendly option for homes.

During frigid Iowa winters, it's often misinterpreted that a heat pump is an unrealistic choice to keep you warm in low temperatures; however, heat energy still exists. A heat pump system is extremely effective at taking this energy from the ground or the air and using it as heat for your home. We’re here to break down those myths and share how a residential heat pump works, explain the different types of systems and recommend if you should replace your furnace with a heat pump system.

How Do Heat Pumps Work?

A residential heat pump works by transferring heat from one location to another by using a refrigerator cycle. Below are the steps that it takes to heat a room:

  1. Evaporation: The refrigerant in the heat pump absorbs heat from the outdoor air (even in cold temperatures) through an outdoor coil. As the refrigerant evaporates, it turns into a low-pressure gas.
  2. Compression: The compressor increases the pressure and temperature of the refrigerant gas, making it hotter.
  3. Condensation: The hot refrigerant gas is pumped into the indoor coil, where it releases heat into the indoor air as it condenses back into a liquid.
  4. Expansion: The refrigerant then goes through an expansion valve, reducing its pressure and temperature and preparing it to repeat the cycle.

When cooling your space, the process is reversed. The indoor evaporator coil transfers hot air outside, then the evaporator coil is condensed into a cold liquid, which is blown into the room by the heat pump fan. A heat pump’s efficiency is three to five times more than natural gas boilers, according to the International Energy Agency.

Graphic on how heat pumps work during the seasons.

Source: mepskills.com

Types of Heat Pumps

Heat pumps offer an efficient and versatile solution for heating and cooling your home, utilizing the principles of thermodynamics to transfer heat from one location to another. However, not all heat pumps are created equal, and understanding the different types available can help select the most suitable option for your needs.

There are two main types of residential heat pumps: air-source and ground-source. As always, if you’re unsure what would work best for your home and needs, don’t hesitate to reach out to the Lozier HVAC team.

Air-Source Residential Heat Pump

In the summer, heat pumps work similarly to an air conditioner to cool your home, using a refrigerant to absorb heat and transfer it outdoors. During the winter, the cycle is reversed and the heat pump extracts heat energy from outdoor air and transfers it into your home. The refrigerant absorbs the heat from the air and pressurizes it to raise the temperature. The warm air is then released into your home until the heat is extracted and condensed back into a liquid to continue the cycle. These heat pumps are the simplest and least expensive, but their efficiency becomes a problem in colder climates.

Ground-Source Residential Heat Pump

Ground-source or geothermal heat pumps absorb heat from underground to transfer it indoors or outdoors. The most common type of ground-source heat pump uses buried pipes filled with refrigerant or water to transfer heat. The pipes can be part of an open or closed-loop system to either pump new water in and out through an underground water source or circulate the same water through the pipes repeatedly. One con to this type of heat pump is that it’s expensive to install because drilling is required to reach the system of underground pipes.

Heat Pump vs. Furnace: Pros And Cons

The main distinction between a heat pump and a furnace is that, unlike furnaces, a heat pump system does not generate heat, but instead transfers heat. This makes heat pumps more energy efficient. While both types of HVAC systems can provide a comfortable environment inside your home, there are a variety of factors that can affect which option may be better suited for your heating needs.

Climate Considerations for a Heat Pump

During Iowa winters, where the temperature regularly falls below freezing, a furnace can generally heat your home more efficiently than a heat pump. If you live in milder climates, a heat pump can provide adequate heating inside your home without too much energy. However, the colder it gets the harder it is for the heat pump to transfer heat to your home. We recommend pairing a furnace and a heat pump to create a dual fuel system that can handle mild and below-freezing temperatures, so you’re able to switch between heat sources depending on the outdoor temperature your home heating needs.

Space Constraints for a Residential Heat Pump

Heat pumps typically require less space than a furnace and exist outdoors, rather than a furnace that lives indoors and requires at least 30 inches of clearance for fire purposes. Though traditional air-source heat pumps also require an indoor air handling unit, they don’t require additional safety clearance and fit more comfortably in small spaces. Depending on the type of heat pump you choose, the air handling unit may be able to be mounted high on the wall to avoid taking up additional floor space as well.

Lifespan and Maintenance

Because furnaces are only used during the colder months throughout the year, they generally have a longer lifespan of 20 years or more and require less maintenance than heat pumps. Since heat pumps can provide an alternative to both a furnace and an air conditioner, their life span is typically a bit shorter at around 15 years and potentially require more maintenance due to having more parts than a furnace. However, because heat pumps can warm or cool your home, you can forgo the cost of an air conditioner and the maintenance it may require with the installation of a heat pump.

Should I Replace My Furnace With a Heat Pump?

A heat pump’s efficiency is a big pro for homebuyers who are looking for an environmentally-friendly alternative solution to an A/C and furnace. They can cool and heat your home in an efficient way to keep you and your family comfortable all year round. They’re a great option if you live in a moderate climate. However, Iowa winters can get extremely cold and heat pumps operate less effectively in subfreezing temperatures. That’s why we recommend pairing your heat pump with a furnace to create a dual fuel system.

Are You Looking To Install A Heat Pump System In Your Home? Call To Get A Quote From The Experts At Lozier!

If you’re considering installing a heat pump system in your home, contact a licensed HVAC technician at Lozier! Call us at (515) 267-1000, text us at (515) 393-4262, or use our contact form to schedule an appointment for a technician to provide a free quote and discuss what options best fit your needs.