Choosing appliances: heating and cooling
When weighing up the cost of your appliance, often the initial price does not tell the whole story
The two most popular and most energy-efficient fully installed electricity-based heating options are reverse-cycle air conditioning and hydronic heating
Where you locate, how you use your air-conditioner will impact its efficiency
Think about installing ceiling or pedestal fans as a cheaper alternative
Plug-in appliances account for an average of 25% of total residential energy consumption across Australia. In some cases, home appliances account for nearly 50% of all energy use in a home, and 45% of total Lifecycle Carbon Emissions (LCE) over the home’s 50-year life.
You could save a considerable amount of money over time by looking at running costs as a ‘second price tag’ and choosing products accordingly. Many appliances with a less expensive purchase price may end up costing you far more in energy costs over the lifetime of the product.
There are advantages and disadvantages to reverse-cycle air conditioning and hydronic heating, and either may suit some people, house designs and climates better than others. Other options include resistive electric heaters, convection heaters, and hydronic installed in-floor water pipes.
Reverse-cycle air conditioners are the most efficient form of electric heating commonly available—indeed, their efficiency is usually of the order of several hundred per cent. They are often referred to as heat pumps since they pump or move heat from one place to another. Because they source or sink their heat into the outside air, they are known as air-sourced heat pumps.
Modern reverse cycle air conditioning systems are becoming more efficient, particularly in terms of energy consumption and cost, making them a very good investment in comfort and health. As electricity prices continue to rise, efficiency is becoming increasingly important. For example, one kWh of electricity consumed, will generate three or more kWh of heating or cooling.
Heat pump hydronic heating moves heated water through one or more pipe circuits to one or more radiators inside the home, which may be wall-mounted radiators or in-floor pipe coils, or both. Though more expensive and complicated to install, most hydronic systems have multiple circuits to allow zoning, where you can heat all or only part of a home. Heat pumps can change the temperature by concentrating this energy and shifting it around.
Heat pump systems include a storage tank for thermal storage and to provide a buffer, which allows the boiler to run heavily and then turn off, allowing the boiler to operate at maximum efficiency.
When it comes to staying cool there are ways to maximise your reverse cycle air-conditioner. You can also think about installing ceiling fans as a more energy efficient option. It’s no surprise that the harder your air conditioner must work to cool down your room, the more electricity it’s going to use and the more it will cost you.
A standard air conditioner’s temperature should be set to 25 to 27 degrees for cooling in summer, and around 18 to 20 degrees for heating in winter. This is to ensure maximum energy efficiency from your unit.
To reduce the running costs of your air-con unit/s make sure you:
- Get the correct-sized unit for your home;
- Make sure the unit is correctly positioned;
- Make sure your unit is regularly maintained and the filter kept clean so it can work as efficiently as possible;
- Invest in a smart air con with app capability so you can switch it off remotely if you forget to turn it off when you leave the house.
Some heat pump hydronic systems can also provide cooling in summer, just like reverse- cycle air conditioners. Not all heat pump systems do this, so if cooling is required then you will need to specify this to your system designer when getting quotes.
The evenings are usually cooler so set your air conditioner to turn off later in the evening while you sleep. Keep your house cool and shaded so your unit doesn’t have to work unnecessarily hard. Use a pedestal fan or ceiling fan to help circulate the warm or cool air produced by your air conditioner. A ceiling fan works well to move cool air through the house, and a pedestal fan placed on the ground is better for circulating warm air.