Choose the right heating system for your home

This system has one outdoor unit that extracts heat from the outside air and transfers it to multiple indoor units (or heads) in different parts of the home through refrigeration piping. Each indoor unit is like an individual split-system air conditioner and blows hot or cold air into the room. It can be used for both heating and cooling.

Each indoor unit can be switched on or off independently and has its own thermostat control. Depending on how much space you want to heat, the indoor units can be operated:

• all at once
• one at a time
• several at a time.

Air temperature is controlled by a thermostat on each indoor unit.

This system doesn’t generate heat directly using an electric element. Instead it uses heat pump technology to extract heat from the outside air. This makes it the most efficient form of electric heating.

Pros

• Most efficient electric heating.
• Can be zoned so you only heat the areas you use.
• One unit provides both heating and cooling.
• Less heat losses than ducted systems.

Cons

• The system compressor, which is located outside, may be noisy when operating, and this can impact your neighbours. Council may have noise level regulations.
• Significant purchase and installation costs, but generally cheaper than a ducted reverse-cycle system.
• You may need to have a switchboard upgrade or three-phase power for larger systems, as they can have high electricity consumption. This will add to the installation cost.

Buying new

Talk to your supplier or retailer about what size system would work best to heat your home. If you have a big home, you may need two multi-split systems to get good coverage.

Energy rating

New multi-split reverse-cycle air conditioners with a cooling capacity less than 30kW are required to have a Zoned Energy Rating. The higher the rating the more efficient it is. Read about Zoned Energy Rating Labels on the Energy Rating website.

The systems are required to have a Zoned Energy Rating but are not required to display it on a label when sold. Ask the supplier or retailer about the rating.

Use it efficiently

We recommend you set your thermostat between 18°C to 20°C. Every 1°C higher will add around 15% to your heating bill.

Clean the filter of the indoor units (heads) every month to ensure that the system operates effectively.

It’s important to have the air conditioner serviced regularly, as per the manufacturer’s instructions, to ensure it continues to operate efficiently.

Check how much multi-split reverse-cycle heating could cost to run.

This system provides whole house heating and cooling through ductwork connected to a central heat exchanger and air handling unit (the indoor unit) which is, usually located in the roof space. A compressor (the outdoor unit) is located outside and uses heat pump technology to extract heat from the outside air when heating and transfers it to the indoor unit through refrigerant piping. This heat is transferred to the air passing through the indoor unit via a heat exchanger and then blown through the ductwork to outlet units located in the ceiling or sometimes the floor.

The air then makes it way back to the indoor unit via the return air grille and ductwork to be re-heated.

The indoor air temperature is controlled by a separate thermostat.

This system doesn’t generate heat directly using an electric element. Instead, it uses heat pump technology to extract heat from the outside air. This makes it one of the more efficient forms of electric central heating.

Pros

• One unit provides heating and cooling.
• An efficient form of electric central heating.
• Most systems allow the home to be split into several zones, which means the area being heated or cooled at any time can be reduced.

Cons

• The system’s compressor, which is located outside, may be noisy when operating and this can impact your neighbours. Council may also have noise level regulations.
• There are energy losses in the ductwork, meaning that ducted systems are less efficient overall than multi-split and single-split systems.
• You may need to have a switchboard upgrade or three-phase power for larger systems, as they can have a high electricity consumption. This will increase the installation cost.

Buying new

When buying a new system, you have the choice between two types of compressors:

• Standard compressor, which switches on and off based on the thermostat control.
• Variable-speed compressor (also known as an inverter), which is much quieter and more efficient than a standard compressor and will have lower operating costs over the heating season. The compressor runs at a lower speed when the room has been brought up to temperature.

There are some energy losses through the ductwork when the air conditioning is operating, and these can be quite high in older systems where the ducts may not be well insulate and/or may have deteriorated.

When having a new system installed, ask the installer about the R-value of the ductwork. This is the level of insulation. The better it is insulated, the lower these heat losses will be and the more efficient it will be.

If you are replacing a gas ducted heating system with a ducted reverse-cycle air conditioner, you will need to have new ductwork installed. The ductwork has a larger internal diameter than that used for gas ducted heaters and new ductwork tends to have a higher thicker insulation, so the outside diameter of the new ductwork will be larger. This may mean that it is not possible to run the ductwork under a floor if this is where the ducts for you gas ducted heater are located. It may be possible to run the ductwork through the ceiling. The size of your return air grille may also need to be increased.

Energy rating

New ducted reverse-cycle air conditioners with a cooling capacity less than 30 kW are required to have a Zoned Energy Rating. The higher the rating the more efficient the system is. Read about Zoned Energy Rating Labels on the Energy Rating website.

Ducted systems are required to have a Zoned Energy Rating but are not required to display it on a label when sold. Ask the supplier or retailer about the rating.

Use it efficiently

We recommend you set your thermostat temperature between 18°C to 20°C. Every 1°C higher will add around 15% to your heating bill.

The most efficient way to use your system is by zoning it. This allows you to split the house into different heating zones, so that you can limit it to only heat the areas you’re using.

The ability to zone your system depends on the design of your home and the placement of the return air grille. The better the zoning capability, the more control you’ll have over the energy consumption and running costs of the system.

It may also be possible to set different fan speeds and different thermostat temperatures for different zones, providing you with an extra level of control.

Clean the filter of the return air grille every month to ensure that the system operates effectively.

It’s important to have the air conditioner serviced regularly, as per the manufacturer’s instructions, to ensure it continues to operate efficiently.

Check how much ducted reverse-cycle heating could cost to run.

Gas ducted heating draws air from inside the home, heats it in a gas furnace and blows it through ducts to outlets located in different areas of your home.

A thermostat, usually located near the return air grille, is used to control the inside temperature.

Pros

• Can heat your home quickly.
• Some systems can be zoned so that you only heat areas you’re using.
• In some cases, separate zones can be controlled by different thermostats.

Cons

• The air circulation fans consume a fair bit of electricity.
• Usually operated on natural gas but will cost significantly more if run them on LPG.
• More expensive than a gas room (space) heater to install and operate.
• More expensive to operate than electric reverse cycle air conditioning systems.
• A separate air-conditioning system will be required to meet the home's cooling needs.

Buying new

If you have a builder, ask what energy (star) rating the gas ducted system has. It’s worth paying more for a high efficiency heater (5 stars or higher), as you’ll save more in the long run. Consider a system with zoning capability to save even more.

These systems lose energy through the ductwork when operating. To minimise energy loss, ask the installer about the R-value of the ductwork. This is the level of insulation.

Aim for an R-value of 1.0 or higher. But be aware, the higher the R-value, the larger the diameter of the ductwork and, in some cases, this could limit the ability to run the ductwork under a suspended floor.

Energy rating

Gas ducted heaters have Gas Energy Rating labels to allow you to compare the energy efficiency of different heaters. The higher the rating the more efficient the heater is.

Use it efficiently

We recommend you set your thermostat temperature to between 18°C to 20°C. Every 1°C higher will add around 15% to your heating bill.

If you can, zone your system so that it only heats the areas you’re using.

Clean the filter of your return air grille monthly during the heating season to make sure the system operates effectively.

Have the gas furnace serviced at least every two years, to make sure it operates efficiently and safely.

Check how much gas ducted heating could cost to run.

Gas fired hydronic systems heat the whole house by heating water in a gas boiler and circulating it through pipework to one of the following:

• radiator panels located against walls in different rooms (most common)
• pipes embedded in a concrete slab
• fan-coil units located on walls near the ceiling in different rooms.

The water then returns to the gas boiler to be re-heated.

The system is controlled by a thermostat monitoring the temperature of the room.

Pros

• Radiators don’t blow heated air or dust around the home, so they’re a good option for people who suffer from allergies or asthma.
• Radiator and in-slab systems provide a comfortable and less ‘drying’ heat.
• Can be zoned so you only heat spaces you’re using.
• Radiator and in-slab systems are a quiet heating source.

Cons

• Takes longer to heat spaces than air-based central heating systems, like gas ducted or ducted reverse-cycle systems.
• More expensive to install because of the cost of pipework and radiator panels.
• Usually operated on natural gas but will cost more if run on LPG.
• A separate air-conditioning system will be required to meet the home's cooling needs

Buying new

There are some energy losses from the pipework when the heating is operating.

When having a new hydronic heating system installed, ask the installer about the R-value of the cladding applied to the pipework. This is the level of insulation. The better it is insulated, the lower these heat losses will be and the more efficient it will run.

Energy rating

There are no energy rating labels for gas hydronic heating in Australia, although the supplier should be able to provide information on the efficiency of the gas boiler.

New systems should have a boiler with an efficiency in the range of at least 75% to 85%. For higher efficiency consider a condensing boiler with an efficiency in the range of 89% to 94%. The higher the efficiency, the lower the running costs.

Gas boilers for hydronic heaters sold in Europe are required to have a European energy rating label. Suppliers of these products should be able to provide information on this rating. The rating is based on a G (lowest efficiency) to A (highest efficiency) scale:

• D is 78 to 82% efficient
• C is 82 to 86% efficient
• B is 86 to 90% efficient
• A is more than 90% efficient.

Use it efficiently

We recommend you set your thermostat temperature between 18°C to 20°C. Every 1°C higher will add around 15% to your heating bill.

These systems can be zoned. Radiators in individual rooms can be switched off by turning off the hot water supply, allowing you to limit the heating to just those areas where it’s needed. In some systems, there’s a thermostat in each room or zone, giving another level of control.

Have the gas boiler and pumping system serviced at least every two years, to make sure it operates efficiently and safely.

Check how much gas hydronic heating could cost to run.

Electric heating cables are laid in the concrete slab when the house is built. They heat the concrete to a low temperature and the surface of the floor acts as a low temperature radiator, as well as heating the air in the room above.

Electricity is switched on to heat the slab for around 7 to 8 hours at night, using the cheaper off-peak electricity tariff. The slab then slowly releases the heat into the house over the day.

This system may require an afternoon boost of electricity to heat the home comfortably during the evening on a very cold day.

It is usually possible to split the system into several heating zones. The operation of the heating in each zone is controlled by a thermostat.

Typically, the heating cables installed will have a power consumption of around 160 to 200 Watts per square metre of floor area heated. This can lead to a high electrical load when the heating is operating (for example 16 to 20 kW for heating 100m²).

A concrete slab can store a large amount of heat. It can take several days to bring the house up to a comfortable temperature and it will stay warm for several days once the heating is switched off. This means the system is not highly responsive, so if there are several warm days during the heating season, the house may be too warm, even if the heating system is turned off.

These systems are usually switched on at the start of the heating season and remain switched on until the end of the season, providing heating to large areas of the home all day, every day. They are best suited to very cold climates with a well-defined heating season but are one of the most expensive heating systems to operate.

Pros

• Runs on cheaper, off-peak electricity rates.
• Heats evenly which provides a very comfortable heat.
• Can be zoned so you only heat areas you need.
• Doesn’t blow heated air or dust around the home, so it’s a good option for people who suffer from allergies or asthma.

Cons

• Not very efficient as there are heat losses from the concrete slab.
• Uses a lot of electricity.
• The electricity is consumed overnight, so they do not use electricity generated by a rooftop solar PV system.
• High greenhouse gas emitter.
• Not very responsive – takes a long time to warm up and cool down.

Buying new

This system is laid in the concrete slab when building a house. You can only install this system in new builds.

Insulate the edge of the concrete slab to reduce heat losses.

Split the home into several zones that can be controlled separately to give you more control over the system’s energy consumption.

Energy rating

There are no Energy Rating Labels for in-slab electric heaters. All systems have essentially the same efficiency.

Use it efficiently

Set the thermostat to a lower temperature than you would normally use for systems that heat the air. Otherwise running costs can be very high. You should still be comfortable at these temperatures as they both radiate heat and heat the air.

Recommended temperatures are:

• 18°C in living areas
• 16°C in bedroom areas.

Consider lower temperatures in areas with large north facing windows, as they will be heated by the sun during the day.

Don’t lay carpet or timber flooring over in-slab heating, as it acts as insulation, reducing the efficiency of the heat transfer from the slab into the house.

Check how much electric in-slab heating could cost to run.

Room reverse-cycle air conditioners heat and cool a single room or open plan area. They are available as:

• split systems
• window-wall mounted units (less common).

Split systems have an outdoor unit that extracts the heat from the outside air and transfers it to an indoor unit that contains a heat exchanger and fan to blow the heated air around the room.

Most indoor units are wall mounted, although floor and ceiling mounted units may also be available.

Split systems are now one of the most common air conditioner types sold in Australia.

Window-wall mounted units are no longer very common, but are still found in older houses. They’re less efficient and noisier than split systems.

These systems don’t generate heat directly using an electric element. Instead, they use heat pump technology to extract heat from the outside air. This makes them the most efficient form of electric heating.

Pros

• Most efficient form of electric heating.
• Generally, the cheapest option for room heating.
• One unit provides both heating and cooling.

Cons

• The system compressor, which is located outside, may be noisy and this can impact your neighbours. Council may have noise level regulations.
• You may need to have a switchboard upgrade or three-phase power for larger systems, as they can have high electricity consumption, and this will increase the installation costs.

Buying new

Room air conditioners are available in a wide range of output capacities. It’s important that the unit you choose is sized correctly for the room or area it’s heating.

When buying a new system either:

• provide the installer with a floor plan of your home showing the room or area to be heated
• the installer should visit your home to undertake an assessment of your heating requirements.

They will need to know:

• the size of the area being conditioned
• if insulation is installed on the ceiling or in walls
• the size and location of windows.

Almost all room split systems sold now are ‘inverter’ models, which have a variable speed compressor. These are more efficient and generally quieter than the older compressors.

Window-wall units are less efficient and noisier than both standard and inverter split systems.

Energy rating

All room reverse-cycle air conditioners with wall mounted and floor mounted indoor units are required to have Energy Rating Labels. The higher the rating the more efficient the air conditioner is.

Split systems that have a ceiling mounted indoor unit and three-phase split systems are not required to have Energy Rating Labels but are required to have energy ratings.

All split system air conditions that have an energy rating label now use the Zoned Energy Rating Label that shows the energy rating of the air conditioner based on its efficiency over a typical heating or cooling season, in three Australian climate zones:

• cold
• average
• hot.

Most of Victoria is covered by the cold zone, although the north-west corner of Victoria is covered by the average zone. The labels make it easier to identify the air conditioners that perform best in the different climates.

The label also provides information on the measured noise level produced by the air conditioner in decibels (dB(A)). The outside noise level is important, as local councils are likely to place restrictions on noise levels in adjoining properties.

Read about Zoned Energy Rating labels on the Energy Rating website.

Use it efficiently

We recommend you set your thermostat temperature between 18°C to 20°C. Every 1°C higher will add around 15% to your heating bill.

Clean the filter of the indoor unit of the split system or the window-wall unit every month to ensure that the system operates effectively.

Have the air conditioner serviced regularly, as per the manufacturer’s instructions, to ensure it continues to operate efficiently.

Check how much reverse-cycle air conditioning could cost to run.

Fixed electric heaters are usually fixed to a wall and are hard-wired to the switchboard.

They have a larger heating capacity than a portable electric heater, generally in the range of 3 to 4 kW.

They are fan convection heaters that heat air and blow it around the room. They can heat medium to large sized rooms of up to 30 to 50 square metres.

They have higher running costs than other heating options for heating the same area.

Fixed electric heaters are no longer very common but can be found in older houses and units.

Pros

• N/A

Cons

• High electricity consumption when operating.
• Expensive to run.

Energy rating

There are no Energy Rating Labels for fixed electric heaters.

Use it efficiently

We recommend you set your thermostat temperature between 18°C to 20°C. Every 1°C higher will add around 15% to your heating bill.

Close off the space that you’re heating to minimise the area. Block any draughts.

Consider having it replaced with an energy efficient room reverse-cycle air conditioner. The annual energy bill savings will recover the cost of the new air conditioner in just a few years.

Check how much fixed electric heating could cost to run.

Portable electric heaters that plug into a power point come in a range of heating capacities, but the maximum possible is 2.4 kW.

They’re designed to heat a single room or small area of up to 20 to 30 square metres, for short periods.

While fairly cheap to buy, they are expensive to run for long periods.

Portable electric heaters include:

• fan convection heaters
• oil filled column heaters
• free standing panel heaters
• fixed panel heaters located on a wall.

These types of heaters use an electric element to produce heat.

Fan convection heaters blow heated air around the room.

Oil-filled column heaters and panel heaters have hot surfaces that heat the air directly. They also produce some low-temperature radiant heat. As these heaters don’t have a fan to circulate air, they usually take longer to heat a room to a comfortable temperature. They don’t blow air around so they’re a better option for people who suffer from allergies.

Pros

• Cheap to buy.
• Usually portable.

Cons

• More expensive to run than most room heaters.
• Low heat output compared to most room heaters.
• Expensive to run for long periods of time.
• Only suitable for small rooms.

Buying new

These heaters are best suited to small living areas or bedrooms, where lower cost heating options are not available.

Choose one with a good quality electronic thermostat and digital temperature setting to control the air temperature more accurately and lower running costs.

Energy rating

There are no Energy Rating Labels for portable electric heaters.

All portable electric heaters have essentially the same level of efficiency, but the effectiveness of the heating provided by different heaters can vary.

Use it efficiently

If the heater has a thermostat, we recommend you set the temperature to between 18°C to 20°C. Every 1°C higher will add around 15% to your heating bill.

Close off the space that you’re heating to minimise the area. Block any draughts.

Portable electric heaters can have built-in thermostats, but these may not always be very accurate.

Check how much portable electric heating could cost to run.

Gas room heaters are often fixed and designed to heat a single room or open plan area by burning natural gas or LPG.

There are two types:

• convection gas heaters just heat the air and blow it into the room
• radiant-convection gas heaters use a combination of radiated heat and heated air (less common).

Pros

• Heats only the areas being used and doesn't have ductwork so cheaper to operate than gas ducted heating.

Cons

• Unflued gas heaters require very specific installation conditions. They cannot be installed as a new heater, and can only be used as a replacement in some circumstances.
• Open flued and unflued gas heaters must be used with adequate ventilation to ensure safe operation.
• In Victoria, unflued gas heaters can only be installed where replacing existing unflued LPG heaters and no natural gas is available.
• A separate air-conditioning system will be required to meet the home's cooling needs.

Buying new

If you have high ceilings, consider one of the following:

• radiant-convection heater, which works best when people are located directly in front of the heater
• convection heater with reversible ceiling fans to distribute the heat more effectively.

Gas heaters can either be flued or unflued.

Flued gas heaters are permanently installed. The flue expels the combustion products from burning the gas to the outside air. They can have an open flue or be ‘room sealed’ (also called balanced flued). Open flued heaters draw air from the room to burn the gas. Room sealed heaters draw air from outside to burn the gas.

If you have a new or well-sealed home, you should use a room sealed gas heater. Unflued and open flued gas heaters shouldn’t be used because they need adequate ventilation to operate safely.

Read Energy Safe Victoria’s safety alert for open flued gas heaters.

Unflued gas heaters produce a lot of water vapour which can cause condensation and mould.

In Victoria, installing new unflued gas heaters is banned. However, if you have an existing unflued LPG heater, you can replace it with an unflued gas heater, as long as it meets these requirements:

• nitrous oxide emissions less than 2.5ng/J
• a CO/CO₂ ratio of less than 0.002
• there must be permanent (or fixed) ventilation
• the size of the heater must meet the requirements of the size of the room and whether there’s a thermostat.

You should consult a qualified gas fitter if you are replacing an existing unflued gas heater.

Energy rating

Gas room heaters have Gas Energy Rating labels to allow you to compare the energy efficiency of different heaters. The higher the rating the more efficient the heater is.

Use it efficiently

We recommend you set your thermostat temperature between 18°C to 20°C. Every 1°C higher will add around 15% to your heating bill.

If you’re using natural gas for heating water and cooking, a natural gas heater provides a mid-range cost option for heating your home, although will be more expensive than a room reverse-cycle air conditioner. You pay an annual supply charge of around $300 to $400 a year for a natural gas connection. This adds to the heating cost if you only use natural gas for heating.

Have your gas heater serviced by a qualified gas-fitter at least every two years, to ensure that it’s operating safely and efficiently. They should inspect the flue and test the carbon monoxide emissions.

Read about Energy Safe Victoria’s guide to heating your home with gas.

Check how much gas room heating could cost to run.

Slow combustion wood heaters burn wood in a metal firebox. Room air is drawn in at the base of the heater and is heated when it passes around the back and sides of the firebox. Heated air is expelled from the top of the heater either by natural convection or with a convection fan.

They also generate radiated heat, both from the body of the heater and through the glass front of the heater.

Slow combustion heaters can produce a large amount of heat and can be used to heat large open plan areas.

The distribution of the heated air will be best if the heater has a fan. Reversible ceiling fans can be used to get a better distribution of heat in rooms with a high ceiling.

They can also be used in conjunction with an ‘air shifter’ kit to heat larger areas of the home. The kit uses ductwork and an in-line fan to shift heated air into other parts of the home.

Slow combustion wood heaters are much more effective and efficient than an open fireplace.

Smoke from wood heaters is a source of air pollution, and excess smoke can be a nuisance to neighbours and impact their health. You are required to ensure that wood smoke does not cause problems for your neighbours, and local councils have the power to enforce this. Read EPA’s information on air pollution caused by wood smoke and how to reduce it.

Pros

• If you have access to cheap firewood, they can be a cost-effective option for heating a larger area.

Cons

• Produces air pollution which can be a nuisance to neighbours and impact their heath, particularly when operated incorrectly.

Buying new

Buying the right sized heater is important. A model that is far too large for the area it is heating will have to be turned down which reduces efficiency, creates smoke and can foul the flue with creosote.

Ask the supplier or retailer about the rated heat output of the heater in kilowatts (kW). As a rule of thumb, the heater size should be around one-tenth of the floor area to be heated in square metres. So, a 150 square metre area would require a heater with an output of around 15 kW.

Look for models made to Australian Standard AS4013. These are designed to provide efficient heating with little pollution when used correctly. Heaters made to this standard will show the certification on their Certificate of Compliance.

Make sure the heater is installed according to Australian Standard AS2918.

You should check with your local council before having a slow combustion wood heater installed, as there may be restrictions in place.

Energy rating

There are no Energy Rating Labels for slow combustion wood heaters. However, all wood heaters sold in Australia must be tested to Australian standards and have a particulate (or smoke) emission limit of 1.5 g/kg or less and a heating efficiency of 60% or greater. This test also measures their heat output. A list of certified heaters, providing the tested efficiency and particulate emissions is available from the Australian Home Heating Association.

Use it efficiently

Use good quality, well cured, wood and operate the heater properly for it to operate efficiently and minimise the production of smoke.

If used incorrectly, slow combustion wood heaters can cause unnecessary air pollution.

Regularly maintain the system.

Have the flue of your heater cleaned regularly to prevent the build-up of creosote. It’s important to make sure the top of the flue remains free of obstructions for safe and efficient operation.

Check how much wood fire heating could cost to run.