Stay cool and save money this summer

6 February 2019

With a hot start to 2019 across the country, we’ve compared a range of different household cooling options to show how you could save hundreds of dollars on your cooling costs over the year.

You might be surprised to learn that heating and cooling accounts for around 40% of household energy use in most Australian homes. So, before you crank up the aircon, here are some easy ways to stay cool without cranking up your electricity bill.

The type of air-conditioner matters

  • Running an older air con unit could be costing you more than investing a newer model. The difference in running cost of a 15-year-old split system and one bought today can range between $57 to $166 per year. Also, make sure your aircon is in good shape - since it’s likely you’ll be using a reverse-cycle unit year-round, it’s important to make sure it’s still working efficiently.
  • Think about what will cost you more in the long run - if you’re looking to purchase a portable aircon unit to save a few dollars now, you might want to reconsider. In the long run, a portable air-conditioner can cost you anywhere between $68 to $201 more per year to run than a modern split system or ducted aircon unit.
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Cooling cost savers

  • The temperature you set can make a big difference to your bill - even on those super-hot days it’s best to set your aircon to a minimum of 24°C. Each degree under that uses 5% more energy. For even bigger savings, only use your aircon to cool down individual rooms instead of the whole house – this could save you around $470 a year.
  • Use ceiling fans instead of aircon on days with maximum temperatures between 28°C and 30°C and you could save between $48 and $202 per year.
  • Use your aircon for an hour less on hot days and you could save between $31 and $93 per year.
  • Install ceiling insulation to absorb or reflect between 30-45% of heat entering your home.
  • Double glaze windows and doors to reduce up to 40% of heat entering your home compared to standard glass.
  • Shade your home to keep it out of direct sunlight in summer – think wide eaves, deep verandas, pergolas, adjustable shades, louvres and trees.
  • Dry your clothes on a washing line or clothes rack to save between $46 to $81 per year.

The amount you can save on cooling your home will depend on how hot it is where you live, what you pay for electricity, and the energy efficiency of your existing appliances. The warmer the climate, the greater potential savings that are available by cooling your home more efficiently.

All costs and estimated savings are based on running appliances five hours per day when the temperature is likely to be above 28 degrees. In past three years, the average number of days that exceeded 28 degrees has been 169 days in Brisbane, 66 in Sydney, 55 in Melbourne, and 97 in Adelaide.

Ref 1: http://www.yourhome.gov.au/energy/heating-and-cooling

Ref 2: Based on a circa 2005 split system unit (5kW-6kW output) compared to a 2018 best performing split system when used for 5 hours a day for temperatures ≥28°C in a year in VIC and QLD. Rates based on VIC and QLD rates on Origin’s Maximiser discount plan as of March 9 2018.

Ref 3: Based on a 2018 portable air con and circa 2005 window wall unit which both operate at the same efficiency, when compared to a 2018 best performing split system (both 5kW/6kW output) operating at five hours a day on temperatures ≥28°C in VIC and QLD per year ($415 vs $214 = $201). Rates based on VIC and QLD rates on Origin’s Maximiser discount plan as of 9 March 2018.

Ref 4: Based on an average performing bedroom sized split unit (2.5kW/3.1kW at $119) when compared to an average performing split package (14kW-16.2kW at $882) operating at 5 hours per day on temperatures ≥28°C across Australia. Rates based on VIC, NSW, SA, ACT and QLD rates averaged out on Origin’s Maximiser discount plan as of 9 March 2018.

Ref 5: Based on using a 65 watt ceiling fan for 10 hours a day, compared to a 7.5 kW capacity air conditioner (2.42 kW input) with the thermostat set at 24℃ for 5 hours a day on days with temperatures between 28℃ and 30℃. Rates based on VIC ($48) and QLD ($202) rates on Origin’s Maximiser discount plan as of 9 March 2018.

Ref 6: Based on a 7.7 kW capacity air conditioner (2.42 kW input) used for 5 hours with the thermostat set at 24 degrees on days with temperatures ≥28°C in a year respective of state weather averages. Rates based on VIC ($31) and QLD ($93) on Origin’s Maximiser discount plan as of 9 March 2018.

Ref 7: Sustainable Energy Authority Victoria, 2002 and 2018.

Ref 8: Passive Design Glazing, YourHome.gov.au, 2018

Ref 9: Based on a 5.5kg auto-sensor dryer, consuming 4.5kW per load each week for a year. Rates based between ACT and SA rates on Origin’s Maximiser discount plan as of 9 March 2018.