Your complete guide to the most efficient, effective heater

August 2nd, 2017

Heaters Heating & Cooling

Your complete guide to the most efficient heater

Heating your home in winter doesn’t have to cost you an arm and a leg. All heaters cost money to run, of course… But some are cheaper than others, and some are particularly efficient in certain types of spaces.

But how do you find the ‘right heater’ for your unique space? With such a wide range of options available, choosing the most cost-effective and efficient heating can be tricky and time-consuming.
Fortunately you don’t have to make the choice alone… Whether you’ve got gas or electric available, we’re going to help you find a heating option that will keep you cosy in winter without breaking the bank.

First, measure your room

Measure the room you want to heat

Size matters when it comes to heating. Many of us underheat our rooms or choose the wrong-sized heater for our living spaces, leading to even bigger energy bills and a cold, unwelcoming environment.

So your first step when choosing the most efficient heater is to measure the space you want to heat (in square metres). Simply multiply the room length by its width for your square metre measurement.

Then calculate the power your heater will need

Calculate the area of the room you want to heat

Below are some formulas to help you calculate the power your new heater will need. (Note that if you have high ceilings, large windows or no insulation, you should aim for a slightly more powerful model, as these factors mean less heat is retained.)


Once you have your room’s area in square metres, multiply it by 100. This will give you the approximate power of the heater you’ll need to warm the room – 100W per square metre (a bit more if you live in a cold part of Australia, and a bit less if you live in a hot part).

e.g. A room that’s 3m wide and 5m long has an area of 15 square metres (sqm), and will therefore require a 1500W (1.5KW) electric heater.


Once you have your room’s area in square metres, multiply it by 75. This will give you the approximate power of the heater you’ll need to warm the room – 75W per square metre (a bit more if you live in a cold part of Australia, and a bit less if you live in a hot part).

e.g. A room that’s 3m wide and 5m long has an area of 15 square metres (sqm), and will therefore require a 1125W (about 1.1KW) gas heater.

Then choose the best heater in that power range

Here are our recommendations for a range of different room sizes.

Small to medium rooms (10-25sqm)

Heating a medium sized room

For a smallish room, you should be looking for fast, consistent heat, not maximum power. If you make the mistake of buying a heater that’s far too powerful, you’ll overheat and end up with an uncomfortably large energy bill.

Electric recommendations

The column heaters below are affordable and excellent at retaining heat. While they don’t heat up as fast as less-efficient electric fan heaters, they’re great for keeping a room warm for hours.

Dimplex electric eco column heaterMidea electric oil column heaterDelonghi electric oil column heater

Gas recommendations

The radiant and convector gas heaters below are an excellent option for direct heating. They’re very simple to operate, feature child locks for safety, and project heat quickly into a smaller area.

Note the last option is most powerful and best suited for larger rooms, especially those with high ceilings and no insulation.

Rinnai unflued natural gas convector heaterRinnai unflued natural gas radiant heaterRinnai unflued natural gas radiant titan heater

IMPORTANT: Note that unflued gas heaters will vent their low-level emissions back into the room, so ventilation is a must. They may also cause irritation if you have asthma or skin sensitivities.

Larger rooms (25-40sqm)

Heating a larger room

Larger living rooms, particularly those with higher ceilings or unconventional layouts, are best heated using more powerful gas heaters and higher-powered panel heaters. Rather than heat an area directly, they heat and circulate the air evenly around the room.

Electric recommendations

If you’re able to isolate your room by closing doors and covering windows, the panel heaters below are a good option as they gently heat and circulate the air itself. As warm air rises over time, panel heaters push consistent, precise heat into the cooler areas. Otherwise, you should consider a reverse-cycle air-conditioner for the most effective results in larger rooms.

Atlantic radiant panel heaterNobo Electric Panel HeaterDelonghi Electric Panel Heater

Gas recommendations

The below gas heaters are excellent for bigger rooms because they’re efficient and effective, converting around 90% of the gas energy content into heat and providing powerful, instant heat. While they’re more expensive than electric heaters to buy, gas-heaters are significantly cheaper to run. Note the last option is most powerful and best suited for larger rooms, especially those with high ceilings and no insulation.

Granada unflued natural gas radiant heaterRinnai flued natural gas heaterRinnai natural gas heater

Open-plan areas or whole house

Heating your whole house

Heating options for the whole home or large, open-plan living areas have a costlier outlay, but you’ll recoup the benefits financially over the long-term, as they generally offer a much wider, further range of heating while remaining energy-efficient.

Electric recommendations

The reverse-cycle split-system air conditioners below are among the most cost-effective and energy-efficient heating options in the long run. They distribute air widely and evenly throughout small and large living areas, and are also suited to cooling in warmer months. For a more accurate calculation on the right size for you, check out our Air Conditioner Sizing Guide.

Fujitsu 2.5kW Reverse Cycle Split System Inverter Air ConditionerMitsubishi 3.5kW Reverse Cycle Split Inverter Air ConditionerFujitsu 7.1kW Reverse Cycle Split System Air Conditioner

Gas recommendations

Whole-house gas systems like hydronic and ducted-gas are energy-efficient and slowly gaining in popularity, but they do come with significant installation costs. (Sorry, we don’t sell these products.)


Heating your bathroom

The safest and most efficient option for bathrooms is the panel heater. Along with their compact design, many panels are rated as drip-proof and suitable for bathroom use.

Our recommendations below have been handpicked for bathroom use, and provide a nice ambient heat.

Nobo panel heater for bathroomDimplex glass panel heater for bathroomAtlantic radiant panel heater

Also think about…

Other home heating considerations

With electricity prices on the hike, room size and energy efficiency are definitely important factors to consider, but they’re not the only ones. Here are some other considerations…


If you like waking up to a pre-warmed room in the morning, and coming home to a warm house at night, consider a heater with a timer. That way, you’re only using heat when you actually need it, rather than leaving the heater on overnight or while you’re away, which is costly and ultimately unnecessary. Many column style and gas heaters include programmable timers, allowing you to simply set and forget.

Heaters with inbuilt thermostats are also an excellent option, as they maintain a precise temperature over time. While it’s tempting to jack the thermostat up on colder nights, try to resist the urge, because every degree higher can dramatically affect your energy bill. If you keep it set between 18°C to 21°C, you’ll be comfortable without spending too much on power bills.


If you’re after something you can use to heat more than one room, consider a portable, lightweight model or one with castors. Many electric panel and column heaters come with castors. Unflued gas heaters can also be used from room to room.

WARNING: It’s illegal to use an unflued gas heater in a bedroom or poorly-ventilated room.

Alternatively, you might consider a reverse cycle air-conditioner. As discussed above, they’re great for open-plan and unconventional layouts, as they heat a wide area very cost-effectively. Many models are also versatile enough to heat and cool, so they’re usable all year round.


Here are some helpful safety tips for heating your house:

  • If you have a young family or pets, and you’re worried about burns, avoid radiant heaters with exposed elements. Column heaters and electric panel heaters are generally a safer bet, as they’re only warm to the touch, so they won’t burn.
  • Never use a column heater in a bathroom as they’re not designed to be used around moist environments. Instead, consider a panel heater; many are drip-proof and some can also be wall-mounted to sit flush against the wall and out of harm’s reach.
  • Many more modern electric column and gas heaters come with automatic cut-off and anti-tilt design, which turn the appliance off should it overheat or tip.
  • If you’re interested in a radiant or convector gas heater, consider one with an oxygen-depletion meter. In the event that your room’s oxygen levels start decreasing, the meter will deliver an alert and eventually shut the appliance off entirely to ensure your safety.
  • It’s illegal to use unflued heaters in small or poorly-ventilated rooms due to their emissions.
  • If you live in Victoria, take care to note Victoria’s laws governing the installation and use of gas heaters.


Fan heaters, while more expensive to run over long periods, heat up fast. This Delonghi fan heater is a good example. It emits fast, powerful heat, making it ideal for short-term personal use and for heating up smaller rooms.

The environment

Gas radiant and convector heaters are rated among the greenest options, producing low greenhouse gas levels and significantly less than that of electric heaters. Their level of emissions must be certified by specific Australian standards.

Create a more efficient space

Creating a energy efficient space

Now that you’ve identified the ideal heater for your space, let’s look at some simple ways you can increase the efficiency of your home and ensure it’s heated comfortably and effectively:

  • Cover your windows and doors at night. According to the Victorian Government’s Department of Sustainability, “a single pane of glass can lose almost 10 times as much heat as the same area of insulated wall.”

Insulating your home to avoid heat loss

  • Close doors between rooms to retain heat. Open doors will reduce heating effectiveness dramatically, meaning you’re paying more for less effect.
  • Wear warm clothing! This might seem obvious, but layering up means you’ll conserve more heat.
  • Consider investing in supplementary items such as duvet inners for your bedroom, draught stoppers to stop cold air from leaking in, or heated throws if you want direct, personal short-term heat.
  • Have insulation installed into your roof. Your home will be cooler in summer and warmer in winter. It’s a long-term, year-round solution.
  • If you’re building a new home, renovating, or upgrading, consider installing a whole home heating system like reverse-cycle split-system air conditioning, a gas-powered unflued/flued heater, or hydronic gas heating. Don’t be put off by the larger up-front cost – you’ll appreciate the consistent longer-term benefits of higher-energy efficiency and a more widespread heat distribution.


As you can see, taking the time to choose the right heater isn’t just a lot of hot air. We’ve outlined the most important factors to consider to ensure you make the right choice when it comes to effectively and efficiently heating your home. If you have any other questions and comments about the best heater for you, please leave them below!

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