How much does it cost to run a heater over winter?

Anula Wiwatowska
Apr 03, 2024
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When the weather turns bitter we turn to our trusty heaters, but how much does running that heater over winter actually cost? Prices vary depending on the type of heater, what size heater it is, how long you run it for, and of course what your electric or gas company charges per unit.

Like anything, there are a tonne of variables, but we’ve compiled the information to help you figure out how much it will cost to run your heater over winter. 

How much does it cost to run a heater over winter?

Based on last year’s average gas and electrical pricing, it can cost as low as $80 or as high as $750 to run your heater over winter in Australia. According to our calculations, high powered gas heaters are the most expensive to run, while low wattage electric heaters and split cycle air conditioning will keep your bills luke warm. Note that outdoor gas heaters that require a cylinder have a slightly different equation.

Every heater, and every bill will be different though. In order to determine exactly how much your heater will cost you you’ll need to know;

  • The maximum wattage or maximum Megajoules (MJ) per hour output for your device
  • Your kw/h or MJ usage charges from your electricity and gas company
  • How long you plan on running your heater for each day

When you have these numbers you simply need to multiply your Kw/h or MJ cost, by the number of kilowatts or Megajoule output to determine how much that device will cost per hour. From there you can multiply that number by how many hours per day you’ll likely use your heater, and again by how many days across winter (92). The formula looks like this;

Electric heater
Winter cost = 92 (hours heater is on per day (kw/h charge x kilowattage of device) )
Gas heater
Winter cost = 92 (hours heater is on per day (MJ charge x MJ/h device usage) )

For split cycle air conditioners the math is a little bit different. Since these devices use heat pump technology they tend to run at least at 300% efficiency, meaning each kW of power exerts around three units of heat. This means the heater shouldn’t have to run for as long to achieve the same results as other electric heaters. To get a good estimate of how much running a reverse cycle air con will cost, you can divide the hours a heater is on per day by three.

Split cycle air conditioner
Winter cost = 92 ( (hours heater is on per day / 3) (kw/h charge x kilowattage of device) )

Heater running costs compared

Or if you don’t want to do math (we don’t blame you), you can just look at the chart below. We’ve used the average cost for electricity and gas across Australia, and based the calculations on using your heater for eight hours per day over the season, or 2.4 hours per day for a split cycle.
Heater type
Max wattage/MJ
Coverage
Cost per hour
Average cost to run over winter
Electric8007.25m2$0.11$82.43
Electric100011m2$0.17$123.65
Electric180016.5m2$0.25$185.47
Electric200018.5m2$0.28$206.08
Electric240022m2$0.34$247.30
Gas1337.75m2$0.53$393.48
Gas1545m2$0.62$454.02
Gas1878m2$0.74$544.82
Gas2598.5m2$1.03$756.70
Split cycle320020-25m2$0.45$109.91
Split cycle400020-40m2$0.56$137.39
Split cycle600030-60m2$0.84$206.08
Split cycle800060m2+$1.12$206.08

What type of heater is cheapest to run?

By and large split cycle air conditioners are the cheapest heater to run thanks to their energy efficiency. Split systems run between 300% - 600% efficiency, meaning that for each kW of power they can produce 3-6 units of heat. This means they need to run for shorter periods of time to achieve the same result as smaller electric or gas heaters. 

If you’re not able to install an air conditioner, a portable electric heater is going to be the next cheapest option from both a consumption, and initial purchase perspective. When we widdle it down to hourly running costs, lower wattage electric heaters or low gas consumption gas heaters are cheaper to run. But, there are different answers depending on how you look at the question. 

Gas is on average 10 cents cheaper per unit than electricity, but the usage requirements for gas heaters are typically higher than electrical ones. Singular gas heaters can cover larger spaces than electric heaters, but the wattage equivalent to cover that space with an electric heater costs less per hour to run.

Gas heater running costs

Gas heaters are notoriously dubbed to be cheaper to run, but that isn’t necessarily the case. Depending on the hourly Megajoule (MJ) usage, and the temperate zone where you live, running a gas heater can be significantly more expensive than an electric heater rated to cover the same space. 

According to Energy Made Easy, the average cost per MJ is $0.0411, which is about 10c cheaper than the average cost per kWh in Australia. While this looks like a win towards gas, these heaters consume more gas per hour than electric heaters do electricity. Smaller scale gas heaters use around 6MJ/h on low, or 13MJ/h on high, and end up costing around $0.25 -$0.53 per hour respectively to run. That is the equivalent running cost of an 1800W or 4000W electric heater, not to mention that gas heaters cost more to buy outright than many cheap electric heaters.

Plus the cooler your climate, the smaller the space that a gas heater can adequately warm. In very cold areas like Tasmania, and the snowy areas of NSW and Victoria 25MJ will warm up to 70m2, while in mild temperatures in the north the same heater will cover over 125m2. At the current usage costs, a 25MJ gas heater would cost over $750 at the end of the season if you were to run it for eight hours per day.

There is a lot to consider, but all around gas heaters aren’t necessarily the cheapest heating option out there.

Electric heater running costs

Even though they get a bad rap, electric heaters can be quite inexpensive to use if you know what to look for. The lower the wattage, the lower the heating costs your heater is likely to incur, but it also means the device will cover a smaller area.

For each 1000 watts of power, the electric heater will cover around 9m2, and cost around $0.14 per hour to run. Ceiling height, insulation, and window treatment all play a part in that 9m2 number, regardless it is a good starting point to figure out what kind of power you need. 

You can nab cheap electric heaters from Bunnings, Kmart, and Big W, for under $50, and even at their most powerful (2400W) they’ll only set you back around $0.34 per hour to run. Gas heaters on the other hand start at around $0.25 per hour to run, and go beyond $1 per hour depending on the capacity.

If you run a 2400W electric heater for eight hours a day over winter, then you’ll end up with around an extra $247 on your bill at the end of the season.

Split cycle air conditioner running costs

Split cycle air conditioners are more expensive to buy and install than portable heaters, but they’ll serve you in summer and winter alike and can be surprisingly affordable to run. Split cycle heating costs the same per kw as any other electric heater does, but due to their “heat pump” technology can warm air up to three times more efficiently.

Heat pumps work by pumping air into a condenser where the refrigerant is then warmed and circulated through the air conditioner. Studies have shown that for every kW of energy used, these pumps are able to circulate three units of heat, as opposed to the 1:1 ratio of portable electric heaters. This ultimately means a 3.2kW system would perform as effectively as a 9.6kW, meaning you’ll need to run the system for much shorter periods, around 2.6 hours per day rather than eight.

On the lower power end, a 3.2kW split cycle air conditioner will cost around $0.45 per hour to run and should cover a 10-20m2 room. Larger systems of 8kW will set you back $1.12 per hour but will warm rooms up to 60m2.

How can I save money on my heating bill?

Running a heater is going to cost you, but there are a few things you can do to minimise just how high your winter heating bill will come to.

  • Run your heater on a lower setting - this will minimise how much power or gas is being drawn per hour and cut down the usage costs
  • Set timers - set up your heater to run at short bursts throughout the day rather than for hours on end
  • Seal up cracks where air can escape - unless you’re using a gas heater which requires ventilation, keeping the cool air out will help to keep warm air recirculating throughout the house
Anula Wiwatowska
Written by
Anula is the Content and Social Media Editor within the Reviews.org extended universe. Working in the tech space since 2020, she covers phone and internet plans, gadgets, smart devices, and the intersection of technology and culture. Anula was a finalist for Best Feature Writer at the 2022 Consensus Awards, and an eight time finalist across categories at the IT Journalism Awards. Her work contributed to WhistleOut's Best Consumer Coverage win in 2023.

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