How Heat Pump Systems Work

In places with mild winters, like the Phoenix area, heat pumps are a popular alternative to traditional gas furnaces. In fact, many new construction homes in the area are built with heat pump systems instead of furnaces. Hailed for their efficiency and energy savings, heat pumps are a versatile system for heating and cooling the home, and their operation is relatively simple. Here’s everything you need to know about how heat pump systems work.

What is a heat pump?

A heat pump uses energy to either pull heat out of the air or out of the ground. A heat pump system consists of several main components, including:

  • Compressor
  • Reversing valve
  • Indoor heat exchanger
  • Expansion valves
  • Outdoor heat exchanger
  • Pressure sensors

Heat pumps use electricity and an electric compressor, not a heat coil, to create warm air. The use of an electric compressor makes them more efficient. Heat pumps can also circulate more air than forced air gas-heating systems. Similar to conventional HVAC systems, heat pumps can be installed as split, package, or ductless systems.

Heat pump operation

Heat pumps do not generate heat. Instead, they move heat from one place to another—like from the air outside into your home. This is an effective method of both cooling and heating. Even in cold temperatures, there is still heat in the outdoor air. In the winter, a heat pump uses refrigerant to extract this heat. The journey begins in the compressor, or outdoor unit, where once the refrigerant reaches the indoor unit, cool air is blown over the heat exchanger to remove thermal energy from the refrigerant. This thermal energy then enters your home as comfortable heat.

In the cooling season, this process is reversed. Instead of moving heat indoors, the heat pump sends indoor heat outdoors. An air-source heat pump is the most common type of heat pump, and is best suited for warmer climates. The efficiency and performance of a heat pump can depend on several factors, including variable blower speeds. Choosing a blower speed may come down to cost or energy efficiency, depending on your priorities.

Single speed

This blower motor comes with one speed. It’s the least expensive, but also least efficient, option.


This blower can utilize low, medium, and high speeds. It’s a moderately priced option.

Variable speed

This blower automatically adjusts its speed based on the temperature you set in your home. With this advanced feature, it’s the most expensive blower option, but also the most efficient.


Pros of heat pump systems

Heat pumps are growing in popularity, and it’s easy to see why. The pros of heat pump systems include:

Energy efficiency

A heat pump can transfer up to three times more energy than it consumes. This can reduce the amount of electricity your home uses on heating by approximately 50%, according to the U.S. Department of Energy. Lower energy consumption means lower monthly energy bills, leaving more money in your pocket.

Quiet operation

In contrast to furnaces, heat pumps operate quietly. If you’re bothered by loud noises, a heat pump is a great choice. You might not even notice it’s on.

Year-round usage

With a heat pump system, there’s no need to install two separate cooling and heating systems. Heat pump systems work in both the heating and cooling season.

Cons of heat pump systems

No heating or cooling system is perfect, and heat pumps are no exception. It’s important to weigh both the pros and the cons before deciding if a heat pump system is right for your home.

Higher upfront cost

The initial upfront costs of a heat pump system are higher than the costs of a furnace. But, this investment often pays off over time in the form of lower monthly energy bills.


A heat pump system has higher maintenance requirements than a traditional furnace. This has to do with the fact that a furnace is only used for a few months, while a heat pump can be used all year round for both heating and cooling. Heat pump systems also have more mechanical parts, all of which need maintenance to make sure they don’t break down.

Cooler air

Because heat pumps work by pulling heat from the outdoor air, they aren’t as effective in very low temperatures. If you prefer to keep your home extra toasty during the winter, a heat pump system may not be the right choice. Instead, a heat pump system is perfect if you want a comfortably warm temperature in the home.


How to get the most out of your heat pump system

A heat pump system is a major investment. So, it’s important to get your money’s worth and keep the system working at its best. With a few simple steps, you can get the most out of your heat pump system.

1.      Keep the filter clean

The filter on your indoor unit is designed to keep dust and debris from reaching the system’s essential inner components. It also keeps airborne contaminants from polluting the air in your home. If the filter is clogged, or installed incorrectly, the whole system’s efficiency diminishes. A less efficient system means higher operating costs, and a higher probability that the system will suffer a premature breakdown. We recommend that you inspect the filter monthly and replace it if it looks dirty. Consult your owner’s manual if you can’t locate the filter on your indoor unit.

2.      Listen for signs of trouble

Learn to recognize the normal noises your heat pump makes during start-up, while running, and during shutdown. That way, you can recognize abnormal noises—like hissing, banging, and screeching—and take action.

3.      Keep the outdoor unit clean

Keep plants, grass, leaves, and other debris from restricting air flow in and out of the unit. Any obstructions could impair the unit’s efficiency. If the exterior coils become clogged or dirty with dust, you can use a vacuum to clean them. If the coils are excessively dirty you can wash them with a garden hose, but make sure and turn the main disconnect switch off before you do.

Heat pump systems from Chas Roberts

Proper maintenance is key in keeping your heat pump system running at its best. And, you shouldn’t leave that important job in the hands of just anybody. At Chas Roberts, we proudly install and maintain the following heat pump models.



Whether you’re in the market for a heat pump system or need service on your current one, we’re here to help. Contact us for all your heat pump questions.