Heat pumps: how to reduce your carbon footprint while saving money this winter

<span>Heat pumps are considered to be very efficient and are most commonly used in homes for heating, hot water and dryers.</span><span>Composite: Guardian</span>
Heat pumps are considered to be very efficient and are most commonly used in homes for heating, hot water and dryers.Composite: Guardian

As any Australian who has lived overseas knows, Australia’s houses are uniquely cold. Where residents of other nations enjoy the benefit of stable internal temperatures, Australians are mostly left to endure colder, leakier homes with no central heating that have more in common with open-air tents.

Related: Are heat pumps more expensive to run than gas boilers?

Sweden may have made double glazing on windows mandatory since 1960, and triple glazing may be common in many countries, but Australians have stuck with single. This has much to do with how Australian regulations have lagged – the country only got around to introducing energy efficiency standards into the building code in 2003. Even then, some states like South Australia have, at times, exempted developers from having to comply with national energy efficiency regulations on some projects – a decision that will cost residents more in the long run.

As a wet and chilly winter rolls around, Australians are once again missing out on a cheaper, more efficient way to heat their homes. The rest of the world has already fallen in love with the “magic” technology of the heat pump, but Australians are only just starting to catch on.

Here’s how heat pumps could save you money, reduce your carbon footprint and keep you warm this winter.

What is a heat pump?

Heat pumps are sometimes described as a “reverse fridge”, as they use a mixture of evaporation and condensation to transfer heat from outside a building to the inside – even in cold weather. Heat pumps are considered to be very efficient and though they have several industrial uses, in the home they are most commonly used for heating, hot water, heating swimming pools and dryers.

I have a gas system. What’s the difference?

As the name implies, a traditional gas system requires a gas supply to operate – which represents another bill – and can be prone to annoying issues, like when the pilot light goes out. Heat pumps are electric and turn on so long as there’s power. Both systems require maintenance – it is important to clean a heat pump’s air filter every few months – but heat pumps don’t have the added health and safety risks posed by gas if something goes wrong.

How do heat pumps work?

Heat pumps work by moving heat from the area surrounding the system into the system you are trying to heat. In a hot water heating system, for example, a fan will suck air from outside on to a set of pipes called an “evaporator”. These pipes are filled with a refrigerant that heats up thanks to the difference in temperature. This is then forced through a compressor, which turns it into a gas, raising its temperature and pressure. It is then passed through a heat exchanger that extracts the heat and cools the gas before it is forced through an extraction valve to return it to its liquid state, ready to go again and completing the cycle. If that’s hard to follow, the Guardian has published a helpful illustrated guide to the process.

What does it mean for the environment?

Replacing a gas-fired system with a heat pump means you are no longer burning gas to generate heat. Natural gas is composed of methane, a potent greenhouse gas that can escape from pipes and valves. Not only does this create a safety risk, as natural gas is highly flammable and explosive, but according to the Climate Council, 1 tonne of methane in the atmosphere warms 86 times as much as 1 tonne of carbon. The act of burning gas in heaters, stoves and hot water systems also produces carbon dioxide, the most potent greenhouse gas that is feeding the catastrophic risk posed by climate change, and nitrogen dioxide, which can be hazardous to health if allowed to build up.

Will heat pumps save me money?

Bottom line: yes. Direct comparisons with gas-fired systems are not straightforward. Some estimates suggest switching to a heat pump could bring savings of 60-85%. The ACT government suggests that savings can fall into the 50-80% range. Paired with solar, it is thought a heat pump could be 90% cheaper to run than the gas system it replaces and installing a home battery virtually eliminates the risk posed by power outages.

The only catch is that even as heat pumps deliver the best overall savings – and one fewer bill – they generally have a higher upfront cost of purchase and installation.

How much do heat pumps cost?

Heat pump hot water systems can range from about $2,100 for smaller systems to $6,000 or more for those capable of supporting eight-person-plus households. Heat pump dryers can range from about $800 to $2,000 depending on the system. The individual unit for an air-sourced heat pump may range between $2,000 and $5,000, but as every household is different and depending on the climatic zone you live in, installation and labour costs may vary.

What are governments doing to help?

Though many federal programs have largely been tailored towards businesses, state governments have been increasingly moving to support uptake.

The Victorian government, which has committed to ending gas connections in new homes, ran a program to help low-income and vulnerable households install heat pumps between 2020 and 2023, but continues to offer a $1,000 rebate to help those looking to switch. The Queensland, New South Wales, ACT and South Australian governments also offer rebates and loan schemes on heat pumps, but some research is necessary to check the specifics depending on where you live.

How do I choose the right heat pump?

Like any major purchase, it is important to research what is available in the market and its specific operating conditions. A bigger heat pump hot water system, for example, will cost more but may be overkill for a smaller home, and a cheaper system may not cut it for bigger homes in particular regions. Resources such as YourHome and Choice can assist.