How to choose an energy efficient heater

A high efficiency gas heater or high efficiency reverse cycle air conditioner will cost less to run. By choosing the right sized system for your home you can avoid paying for energy you don’t need.

Heating decision tree

Disclaimer: ‘Whole house’ refers to heating approximately 160 - 170m2. ‘One room’ is approximately 30 – 40 m2. Approximate costs per year, based on 900 hours usage (or around 5 months at 6 hours per day). Based on peak electricity tariff of 27.7cents / kWh, off-peak electricity tariff of 16.6 c/kWh and marginal natural gas tariffs of 1.50 cents / MJ (gas ducted heating) and 1.66 cents / MJ (gas room heating). Actual costs for your house will depend on the area heated, how long you run the heating for, your thermostat settings, how well insulated the house is, your energy tariffs and your local climate.

The tables below compares the different types of heaters and the pros and cons of each system.

Things to consider

Type of heater Description Things to consider
Gas ducted heating Designed to heat the whole house
  • Buy an energy efficient model - make sure it has a minimum energy rating of at least 4 stars. 
  • Choose a system with the ability to be zoned – switch off areas not being used. 
  • Use only well insulated duct work.
Gas fired hydronic system Designed to heat the whole house. These systems circulate heated water through radiator panels, fan-coil units or in some cases via pipes in a concrete slab.
  • Some systems allow for individual room temperatures to be set, and some turned off.
  • Buy an energy efficient boiler (natural gas is the cheapest fuel for the boiler), and make sure the pipework is well insulated.
Ducted reverse cycle air conditioner Whole house heating and cooling through one set of ducts, usually in the ceiling.
  • Sizing is critical and should be done by an expert 
  • Buy the most energy efficient unit you can afford 
  • Use only well insulated ductwork
Electric in-slab heating Electric coils run through a concrete slab, generally runs on a cheaper off-peak electricity tariff
  • Avoid putting carpet or timber flooring over in slab heating.
  • Should be run at a thermostat setting no higher than 18oC, otherwise running costs will be much higher.
Gas room heater

Designed to heat a single room or open plan area. Can be flued or unflued. In Victoria, there are strict regulations around the installation of unflued LPG heaters. Can be run on natural gas or LPG (which is more expensive). Unflued heaters can only be run on LPG.

  • Buy an energy efficient model- make sure it's at least 4 stars.
Reverse cycle air conditioner Designed to heat a single room or open plan area. Split system or window wall models available.
Reverse-cycle systems can both heat and cool.
  • Split systems are quieter than window wall units 
  • Buy the most energy efficient unit you can 
  • Inverter models are quieter and more efficient 
  • Sizing is critical and should be done by an expert
Portable plug in heater Designed to provide single room heating only, for short periods
  • Running costs are determined by the wattage of the heater, so a 1200 watt fan heater will cost the same to run as a 1200 watt column or panel heater. 
  • Buy a unit with a thermostat and timer to keep costs down.

Pros and cons

Type of heater Pros Cons
Gas ducted heating
  • Available in both zoned and un-zoned systems.
  • More expensive than a gas space heater to install and operate.
  • Not ideal for houses with high ceilings
Gas fired hydronic system
  • Good for allergy sufferers
  • Quiet heating source
  • Good choice for high ceilings.
  • Slower response time than air based central heating systems.
  • More expensive than gas ducted heating to install.
Ducted reverse cycle air conditioner
  • Can heat whole house or a number of specific zones. One unit provides heating AND cooling.
  • More expensive than room air conditioner to run, and more expensive than gas ducted heating to install. 
  • Cooling costs in summer add to energy bills.
Electric in-slab heating
  • Some systems allow for individual room temperatures to be set, and some turned off.
  • Good for allergy sufferers.
  • Expensive to run – most expensive central heating system to run.
  • Slow response time. Best suited to cold climates as is usually run 24/7 during winter months.
Gas room heater
  • Very economical to run.
  • Heats only the areas being used.
  • Unflued gas heaters require specific installation conditions. In Victoria, can only be installed where they are replacing existing unflued LPG heaters where no natural gas is available.  
Reverse cycle air conditioner
  • One unit provides heating AND cooling.
  • Cheapest form of electric heating
  • Cooling costs in summer add to energy bills.
Portable plug in heater
  • Cheap to buy.
  • Expensive to run for long periods.

 

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