By Team JSR

Heat pumps have been in use for decades, with around 30% of Kiwi households having one installed. Nonetheless, myths and misinterpretation about their usage continue to persist. These myths cover various aspects, including power consumption, operating costs, maintenance, and what they can and can’t do. To clarify any misconceptions, we’ve addressed five common myths about heat pumps below.

Myth #1: Heat Pumps Are Expensive to Operate

This is one of the most common misconceptions, but commonly misunderstood. Modern heat pumps achieve 300-400% efficiency, meaning that for every 1kW of power consumed, they can produce 3-4kW of heating or cooling. The higher the efficiency of an appliance, the lower its operating costs.

According to the Energy Efficiency and Conservation Authority (ECCA) Electric Homes Technical Report 2024, heat pumps are the most efficient way to use electricity for heating your home. In New Zealand, the benefits of electric heat pumps (or reverse cycle air-conditioners) are well known. Heat pumps can deliver 3-4 times more heating for the same energy input as gas heaters.

While most home heating options have a performance efficiency below 100%—with electric resistance at nearly 100%, gas at about 80%, and wood fires around 65%—heat pumps average around 350%, with some performing even better depending on the region and temperature. Heat pump water heaters, though less common, offer similar efficiency advantages.

Another example of the graph below illustrating the cost comparison of a heat pump with space heating.

Image source: Ellison, J., Thorn, D., Pawson, M., & Griffith, D. (2024). Electric Homes Technical Report. Retrieved from https://www.eeca.govt.nz/assets/Uploads/Electric-Homes-Technical-Report_March-2024.pdf

Myth #2: Heat Pumps Require High Maintenance

Split system heat pumps need minimal maintenance beyond regular filter cleaning. We suggest cleaning the filters at the start of each season to keep them effective at removing allergens like pollen and dust, as well as neutralizing bacteria and viruses. For frequent users, it is recommended to have a professional check-up from a heat pump specialist to ensure the best performance. Heat pumps also feature a self-cleaning mode that dries internal components, helping to prevent mould and keep clean, odour-free air.

Myth #3: Heat Pumps Are Noisy

While the noise level of heat pumps can vary depending on factors like model, size, and fan speed, they are generally very quiet. Thanks to ongoing advancements in technology and design, modern heat pumps are engineered for noise reduction and improved energy efficiency.

Most new heat pumps come equipped with a “quiet mode” feature, designed to minimize noise levels during operation. This mode reduces the fan speed and optimises the compressor’s performance to ensure the heat pump runs as quietly as possible, making it ideal for nighttime use or maintaining a peaceful environment in your home. This innovation reflects the latest advancements in heat pump technology, prioritizing both comfort and tranquillity.

Myth #4: Setting the Temperature Higher or Lower Heats or Cools Your Home Faster

Although it might seem logical, adjusting the temperature higher or lower won’t speed up heating or cooling. Your heat pump will work at the same rate, regardless of the set temperature. The best approach is to set it to a comfortable level and let the system do its job.
If you need quicker results, Mitsubishi Heavy Industries split systems offer a High Power Mode, which provides 15 minutes of boosted airflow to rapidly heat or cool your space—ideal for when you first arrive home or wake up.
Ideally, Daikin split systems also offer a similar mode known as Powerful Mode, offering quick boost or reduction in temperature where needed.

Myth #5: Heat Pumps Are Bad for the Environment

Heat pumps are environmentally friendly due to their high energy efficiency—up to 400%. This means they use far less electricity than other heating and cooling options, reducing their environmental impact.

Additionally, most modern split systems now use R32 refrigerant, which has a much lower Global Warming Potential (GWP) than older refrigerants, further helping the environment. R-32 is a well-balanced refrigerant that has gained significant attention due to its efficiency. By transferring heat more effectively, R-32 can reduce electricity consumption by up to 10% compared to air conditioners that use R-22. Additionally, R-32 has a global warming potential (GWP) that is one-third lower than commonly used refrigerants like R-22 and R-410A, making it a more environmentally friendly option.

Unlike wood burners, heat pumps don’t produce harmful micro-particles, making them better for both the environment and your health.