Gas
Portable gas heaters have some distinct advantages over their electric counterparts - they are available with much larger heat outputs and emit only about one quarter to a third of the greenhouse gases of an electric heater with the same heating ability.

They are generally more expensive to buy than portable electric heaters, but for the same heat output they cost less to run and have less environmental impact (unless you use Green Power to run your electric heater). Portable gas heaters come with a star rating - the more stars (six is best) the less gas used and the lower the operating costs. This also means reduced greenhouse gas emissions. However most have very similar energy ratings.

To compare the energy ratings of gas heaters, visit the Australian Gas Association's web site and look for the 'Directory of Certified Gas Appliances and Components'. This directory is produced on a yearly basis and contains information on the annual energy consumption and star ratings for particular gas appliances, including heaters.

To use one of these heaters, you will need to have a gas outlet (bayonet) fitted by a licensed contractor. They don't need a flue, as they exhaust their hot gases directly into the room, but the room must have adequate ventilation. Unflued gas heaters should be used only in properly ventilated rooms and must never be used in bedrooms or bathrooms (see the Heaters and the Environment section).

Unflued gas heaters emit pollutants into the home and this may pose a problem for people with respiratory illness, certain allergies and asthma sufferers.

Gas heaters are designed to run on either natural gas (piped to your house) or LPG (mainly bottled). It's important to buy the correct type, so if in doubt, ask your retailer about the heater and whether you live in an natural gas or LPG reticulated area.

•	Convection heaters operate much like electric fan heaters and have a similar application. They have an electric internal fan, so they need to be plugged into a power point as well as the gas outlet. The exposed surfaces usually do not get too hot and therefore these heaters are a good option where small children are present.
•	Radiant heaters are comparable to electric bar radiators, but are available with much larger heat outputs.
•	Combination convection/radiant heaters have the advantages of both types and require electricity to operate the internal fan.
	Convection Heater	Combination Convection/Radiant Heater

Electric
These heaters are very common with many models available. They are generally cheapest to buy and, although not as cheap to run as the same output gas unit, they can be reasonably inexpensive to operate if used sensibly. However, they can be expensive to operate if used for long periods of time or if used to heat large areas. The efficiency of all portable electric heaters is about the same.

•	Fan heaters pass air across an internal heating element. They provide near instant heat in small, draught-free rooms.
•	Bar radiators and strip heaters are more effective than fan heaters in open plan or draughty rooms. In-built reflectors direct heat rays towards you and should be kept clean for maximum efficiency.
•	Oil-filled column heaters use electricity to heat the oil inside their fins. The fins then heat the air that moves over them. Some types have a small fan to increase air movement. Column heaters take some time to heat up but the oil stays hot for a while after the power is switched off. If you need instant warmth, a fan heater or bar radiator is a more suitable choice. Column heaters can be safer than other portable heaters because they are not as hot to touch.
	Bar Radiator	Oil-Filled Column Heater
•	Flat panel or film radiant heaters are similar to oil-filled column heaters except without the oil, making them lighter, smaller, quicker to heat up and cheaper to buy. Like oil filled heaters, they don't get very hot, making them suitable for confined spaces or where children might accidentally touch them.
•	Electric blankets are an economical way to keep warm. Rather than heating up the whole room, they heat up a small area - your bed - and therefore use little energy.

Kerosene
Portable kerosene heaters are available in two types - radiant and convection. The fuel can be very expensive if bought in small amounts but is cheaper if purchased in bulk from petrol stations or bulk fuel suppliers. Like other fuel-burning unflued heaters, kerosene heaters should only be used in a properly ventilated room - never in a closed off bedroom or bathroom.