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5 Common Myths About Heat Pumps Debunked

While heat pumps have been around for decades and approximately 30% of all Kiwi households have one installed, there’s still a lot of myths and misconceptions surrounding them and their use.

These myths range from how much power they use, how much they cost to run, maintenance, what you can and can’t do with them, the list goes on. To try and clear a few things up, we’ve covered 5 main myths about heat pumps below.


Myth #1: Heat Pumps Are Expensive To Run

While this is definitely one of the most common myths out there, it couldn’t be further from the truth. Modern heat pumps deliver approx. 300-400% efficiency. This means for every 1kW of power your heat pump uses, it can deliver between 3-4kW in heating or cooling. The more efficient an appliance is, the cheaper it is to run.

Given this, the ECCA (Energy Efficiency and Conservatorium Authority) have confirmed that heat pumps are the most efficient way of using electricity to heat your home.

The graph below compares several different ways to heat your home and their approximate cost in cents per kWh.

comparison heating costs heat pumps
Average running costs based on February 2021 data from

To highlight even further just how cheap heat pumps can be to run, the table below includes some example running costs of various appliances (including heat pumps).

ApplianceApprox. Running Cost Per Hour
Heat Pump$0.09 – $0.25
Oven$0.44 – $0.94
Stove Cooktop$0.30 – $0.59
Microwave$0.20 – $0.37
Clothes Dryer$0.35 – $2.22

Running cots are approximate. Based on $0.25/kwh electricity costs.

Myth #2: Heat Pumps Require A lot of Maintenance

Other than cleaning the filters, split system heat pumps require very minimal maintenance. We recommend cleaning your filters every change of season to ensure they’re working their best to remove allergens like pollen and dust and neutralise bacteria and viruses. You can learn how to clean your split systems via our handy blog here.

If you use your heat pump a lot, we usually recommend having it checked by a professional at least once a year so they can give it a good once over and ensure it’s running as efficiently as possible.

Mitsubishi Heavy Industries heat pumps also have a Self-Cleaning Mode which is designed to dry the internal components, including fan and filters. This helps eliminate mould and deliver clean and odour free air.

Myth #3: Heat Pumps Are Noisy

While operating noise of heat pumps can vary depending on model, size, fan speed, etc. on average, heat pumps are actually extremely quiet! This is thanks to continually improving technologies and design, allowing for noise reduction and energy efficiency enhancement.

To give you an idea of just how quiet some heat pumps are, we’ve included below a list of common noises and their sound levels compared to some of our heat pumps.

ItemAverage Sound Levels (Decibels)
Normal Breathing10db
Avanti PLUS (SRK20ZSXA-W)19db 
Avanti  (SRK25ZSA-W / DXK09ZSA-W)22db
Bronte (SRK63ZRA-W / DXK21ZRA-W)25db
Soft Whisper30db
Rustling of Leaves35db
City Traffic (Inside Car)80db

*Avanti PLUS on ultra-low fan speed, Avanti on low fan speed and Bronte on ultra-low fan speed.

While most of our split systems are quiet as it is – Mitsubishi Heavy Industries split systems also boast a Silent Operation. This reduces the noise of the outdoor unit even further making them even quieter. Perfect for when you may want to run it overnight!

MYTH# 4: Setting The Temp Higher/Lower Heats/Cools Your Home Faster

While it sounds good in theory, this unfortunately doesn’t work. Your heat pump will work equally as hard to heat or cool your space, regardless of what you set the temperature at. Best thing you can do is set your temperature to the comfortable temperature and just wait for the system to do its thing.

If you’re desperate for heating or cooling, Mitsubishi Heavy Industries split systems do have a High Power Mode which delivers 15 minutes of boosted airflow to quickly heat or cool your space. Perfect for when you arrive home or just wake up.

MYTH# 5: They’re Bad For The Environment

Given their high energy efficiencies (up to 400%), heat pumps use a lot less electricity that many other alternatives. The less electricity required, the better it is for the environment!

Most split systems now also use R32 refrigerant, which has a much lower GWP (Global Warming Potential) than previous refrigerants used which is another big benefit for the environment.

Unlike wood burners, heats pumps also don’t generate any micro particles, which can have a negative impact on both the environment and your health.

Thinking of replacing or upgrading your heat pump? To speak with a local MHI installer, who can recommend the perfect solution for you, visit our request a quote page, leave some details and we’ll get a MHI installer to get in touch!

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woman on couch underneath mitsubishi heavy industries split system heat pump
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