Energy-saving guide for Northern Australia
Tropical and sub-tropical living
Staying comfortable in your home in the tropics while reducing energy use doesn’t have to involve spending a lot of money. Whether you’re in Broome, Darwin or Cairns, there are things you can do for free that will reduce your bill while still keeping you cool.
Our tips focus on taking advantage of the climate-friendly features already in your home before resorting to the air conditioner and ensuring it won’t need to work as hard once it’s in use. They may require changing some of your household behaviours. If you’re already taking many of these actions, consider revisiting them, especially if you’ve changed living arrangements or are new to the region.
You can also speak to local expert installers and tradespeople about the best solutions. With good design and careful management of your home, you should be able to stay comfortable while saving money on your energy bills.
Living in the sub-tropics is similar to the tropical zone; however, the mild winters mean some heating may be required. Whether you’re in Mackay or Coffs Harbour, consider how you manage your home for comfort and energy efficiency.
Follow the suggestions for tropical living, noting the sub-tropical tips as you go.
Simple things you can do now
Catch the breeze
Locate the breeze path around your home and open windows, shutters and doors and situate seating areas to take advantage of this at different times of the day and year.
Cool breezes work best in narrow or open plan layouts
If your home design allows cross ventilation, open windows on opposite sides of the room so the breeze can pass through. This only works when outside air is cooler than inside. When it's hot and still, close doors, windows and curtains to keep the heat out.
Take advantage of high windows and vents. As hot air rises it draws in cool night air or cooler daytime air from shaded areas of the building, enhancing the effect of cooling breezes or helping to cool the home when there are no breezes about.
By paying attention to changing indoor and outdoor temperatures you can maximise natural cooling provided by shade and breezes.
Cleaning your fly screens will help to promote the passage of cool air, and can be done with the help of a brush or hose. By circulating air through your home you can also help combat the build-up of mould.
Sub-tropical tip: Closing windows can help prevent heat loss in winter.
Fans are very efficient and are cheap to buy and run (about 2 cents an hour). They can improve comfort levels so that you feel about 3°C cooler.
Fans cool you by moving air across the skin so need to be close to you. Place furniture to take advantage of their effect, and set up pedestal fans where ceiling fans don’t reach.
If you have high ceilings, consider lowering fans on droppers to avoid pushing any warm air near the ceiling down into the room. You can also use fans to increase the effectiveness of your air conditioner—running the two simultaneously allows you to operate the air conditioner more efficiently by running it at a higher temperature setting for a shorter time.
Shop around for the most effective and energy-efficient fans—noise levels and performance vary.
Sub-tropical tip: If heating, switch your fan to reverse rotation to better distribute warm air through the room.
Get in the zone
The bigger the space you need to cool, the greater the energy use and the higher your energy bill. If you need to turn on the air conditioner, close doors to surrounding rooms and only cool the room you’re using.
Set your thermostat from 25 to 27°C and consider running ceiling fans as well.
Some air conditioners have a dehumidifying function. This will use less energy while still delivering a comfortable indoor environment in humid climates, especially if it’s used in conjunction with a fan.
Plan activities and physical pursuits around cooler times of the day. Try rising early to walk the dog or do a spot of gardening, and seeking out a shady spot to enjoy a break.
If you live in an urban area, plan trips to the supermarket or air conditioned spaces to escape hotter parts of the day. In the evenings, head onto the verandah or into the garden and cook the evening meal outdoors.
Open up your home in the evenings to allow cooler air from outside to push out warm air that has collected during the day. This is a beneficial way to cool off if overnight temperatures fall below your inside temperature.
Convection causes warm air to rise, drawing in cool air.
Many homes in tropical northern Australia feature sleep-outs on the verandah to take advantage of the cool night air and the radiant cooling effect from clear night skies. Whatever your solution, make sure you keep an eye on morning temperatures and close up the house again before the day heats up.
Sub-tropical tip: Ventilation in the roof space lets hot air escape and be replaced by cooler air. This helps stop heat transferring through the ceiling to the rooms below and is particularly important in uninsulated homes.
Solar clothes dryer
Drying clothes outdoors, or in front of a fan during the wet season, will reduce your energy bill as well as avoid the build-up of moisture in the home that can lead to mould.
If you need to use a clothes dryer, spin dry on maximum speed first to reduce drying time and clean the lint filter after each load. Running the dryer on medium heat takes longer than when on high, but will use less energy and can be less damaging to clothes.
When buying a new dryer, look for the most efficient model you can afford, and take running costs into account. Heat pump condenser dryers are generally more energy efficient than standard condensing dryers, and may be cost-effective if used regularly. Condenser dryers work by removing moisture from the air before releasing it reducing condensation.
Look for a dryer with an auto-sensing feature that stops as soon as your clothes are dry. To avoid mould and reduce air conditioning load, aim to install your dryer on the verandah or in your carport. Check installation guides for safety information and protect the dryer from the weather.
Quick, cost-effective changes for tropical climates
Monitor the weather
To help read your local weather more accurately, invest in a home weather station with an indoor display or alert system.
These range from inexpensive temperature gauges to digital technology that can measure solar radiation, expected rainfall, wind speed and direction, humidity and more.
By providing you with a convenient read-out from inside the home, they can help you to respond to outside conditions and manage your home more efficiently; for example, by allowing you to operate blinds and awnings effectively and capture passing breezes as they occur.
Switch to energy-efficient lighting
While they might cost more upfront to buy, LED lighting is much more efficient than other forms of lighting and will save you money on your bill over the long term.
A good quality LED bulb consumes 80% less energy than a halogen light and lasts 5 to 10 times longer. They will also reduce the amount of heat in your home, particularly if you’re replacing halogen downlights which run hotter than other lighting technologies. It takes up to 6 downlights to light the same area as one pendant light—so switching to LED bulbs and pendant lighting can have a real impact.
As downlights require a minimum clearance around ceiling insulation they can reduce the effectiveness of insulation. This is another reason pendant, ceiling-mounted or track lighting is a better option. Ask a lighting specialist to provide approved covers with your LED downlights to reduce the impact on insulation. Sealed downlights are another option.
Cool pool technology
Pool pumps can account for around 18% of household electricity use. By making smart purchasing decisions and using your pump efficiently you can reduce your running costs. Select a minimum 5 star energy-efficient pool pump at the smallest pump size for your pool—variable speed pumps often have higher efficiency.
As pool pump labelling is currently voluntary some pumps won’t have a star rating. To get an idea of the true costs of your pump, get your retailer to do a cost comparison between the running costs of an energy-efficient versus a less efficient pump over 3 to 5 years. Follow our tips for running your pool pump efficiently once it’s installed, including using a timer to manage run-time and keeping the skimmer basket and pool filter clean to reduce the load on your pump.
Installing and using a well-fitted pool cover significantly reduces evaporation, pump running times, water bills and the need for chemicals and cleaning.
Plant shade trees and vines
Good shading is vital in hot conditions to reduce the heat entering your home from walls and windows.
Tree shade on the eastern and western sides of a single-storey, older-style 3 star energy-rated home has been shown to bring energy savings of up to 50%.
Shading is particularly important if your home is made of heavier construction such as concrete or bricks which take longer to cool down. Generally, overhead shading is required to block the higher angle sun in summer for north and south facing openings. Adjustable shading from pergolas combats low-angle morning and afternoon sun for east and west orientation of your home. If you intend to install a solar PV system or solar hot water at a future date you’ll need to plan trees to give the sun access to the appropriate area of your roof.
When planting out pergolas, use evergreens to filter unwanted sun. Use drought-tolerant groundcover plants rather than paving to help keep the ground and surrounding surface temperature lower in summer.
If renting, you may be able to get permission or assistance from your landlord for plantings as it will improve the liveability of the home—our renting guide has some ideas. Fruit trees such as mango may take longer to grow than other varieties, but have the added benefit of providing produce as well as shade.
Sub-tropical tip: Make sure plantings allow sun access to the north. so it can warm your home in the cooler months. Floors made of heavier construction will store heat during the day and release it at night to warm your home.
Go solar PV
With new developments in home battery storage, solar energy is becoming even more attractive for Australian households. Our guide to installing solar power has more information.
To assess the benefits get an estimate of how much electricity you use each year and the power you can generate in your particular location. Approach an accredited installer to ask about the right size system.
You may be eligible for financial assistance towards the cost of installing a solar PV system under the Australian Government’s Small-scale Renewable Energy Scheme (SRES). See the Energy.gov.au rebates page for any assistance available and contact energy retailers to find out about feed-in tariffs.
Solar power can significantly reduce your energy bills over time
Switch to an energy-efficient hot water system
Hot water can use 25% of your energy. If replacing your hot water system, take time to research the right type and size of product for your needs. Choose the most suitable and energy-efficient model you can afford to save on energy bills and avoid paying for capacity you don’t need. See our detailed information on hot water.
For tropical climates heat pump and solar hot water are recommended technologies and you may be eligible for financial assistance to help with the cost of installing a system under the Australian Government’s Small-scale Renewable Energy Scheme (SRES). See the Energy.gov.au rebates page for any assistance available.
Ensure you understand the information on safety and maintenance for your new system. This is particularly important for storage hot water systems that you’re switching back on after a period of non-use. The water needs to be heated to above 60°C for at least 35 minutes before use, killing any bacteria that may have grown. It could take several hours for the water to heat above 60°C.
Insulate your ceiling and roof
Insulation helps to keep the sun’s heat out of your home during extreme temperatures, saving on your energy bills.
Insulation can be sensibly and safely added to many existing homes. To take advantage of the improved comfort levels and energy savings that result from its installation, research the correct type and level of insulation for your home and climate or talk to a building professional.
Reflective batt and foil insulation
For air conditioned home, the use of bulk and reflective insulation in the ceiling and roof is recommended. In the ceiling select R3.5 or higher bulk insulation. Consider the use of multiple layers of reflective foil to create a one-way heat valve effect. For walls, use of bulk and/or reflective insulation is recommended.
Under a sheet metal or tiled roof, a reflective insulation system should be used. A tiled roof should have sarking—a double-sided reflective-foil product under the tiles as well as ceiling insulation. Including a foil-blanket system under sheet metal roofing can provide an additional benefit of dampening the sound of heavy rain. Ventilate roof spaces well with fans or whirlybirds and design for condensation removal (see Passive cooling).
Verandah roofs should be insulated with reflective-foil insulation to reduce radiant heat gain, as this impacts on your indoor temperature as well as making outdoor seating areas uncomfortable. Consider installing energy-efficient ceiling fans. Condensation needs to be considered in all roof and wall systems. Seek expert advice when designing and installing your reflective insulation system.
Sub-tropical tip: Roof insulation helps to keep warmth inside your home during the cooler months. Using bulk insulation in external walls is also beneficial.
The first line of defence in cooling your home is to stop it absorbing and storing the sun’s heat. Light-coloured roofs can reflect up to 70% of summer heat gain, helping to reduce the internal temperature and improve comfort levels.
The easiest time to install light-coloured roofing is when you’re building. However, if you need to replace your roof, steel roofing solutions with new reflective paint technology are highly effective. Research to find an option that suits your budget.
Cool steel roofing material with reflective paint technology
Installing a fly roof can shade your entire home, protecting it from radiant heat while allowing cooling breezes to flow underneath.
A fly roof can shade your whole home
Sub-tropical tip: A white roof or shading will affect your home’s indoor temperatures during the cooler months. Allowing solar access to north-facing living areas and sealing gaps and draughts will help you retain warmth when you need it. Protect from direct sunlight with adjustable shading to avoid heat gain in the hotter weather.
Improve your windows
The most significant difference in the design of tropical homes is in the size and orientation of windows or openable panels and doors. If renovating, improving windows to increase air flow can make a real difference to comfort, reducing up to 90% of heat gain.
Windows with maximum opening areas such as louvres or sliding windows can be tightly sealed when closed. Check the seals on existing windows and improve them if necessary. Avoid fixed glass panels.
Louvres and casement windows are best for breeze capture.
A small number of windows on every side of your home will encourage air movement but not access by the sun.
Larger windows or openings should be located on the downwind side of the house and smaller openings on the breeze side. All openings should be well-shaded.
Check with an energy rater or window specialist whether toned or Low e-glass could improve your comfort levels. Consider tinting windows that are exposed to the sun. The choice of windows is a big decision that can have a significant impact on energy use. Your choice will depend on the existing house design so research to find the best window solution.
Clean with vinegar and water (not bleach) to get rid of mould
Mould is a fungal growth that can occur in areas that are damp, dark and poorly ventilated. It grows on a variety of surfaces, including timber and fabrics, wet areas, bathrooms, and kitchens. Rough, porous surfaces are often worst affected. It can damage your home and furnishings.
Mould can have an unpleasant odour and cause irritation and sneezing as well as more serious health risks. To prevent mould, you should aim to control the build-up of moisture and warmth as much as possible.
Keeping your home properly ventilated and letting the sunshine in are common ways of managing mould.
In addition to moisture and lack of air circulation, mould needs surface dust or dirt. Dust, clean and dry surfaces regularly, including walls, window glass and frames, to stop growth of mould spores, particularly in the wet season.
During high humidity keep air circulating with a fan or air conditioner. Look for models with a dehumidifying feature. In your cupboards or under beds use refillable containers with moisture absorbing crystals.
Install exhaust fans in bathrooms and kitchens to avoid build-up of moisture. Where possible ensure stoves, washing machines and dishwashers are fitted with an exhaust system.
If you’re renting and have ongoing problems with mould consider purchasing a portable dehumidifier. Run it overnight to reduce energy demand during peak times and to take advantage of any available off-peak electricity tariffs. Our renting guide has tips on getting assistance form your landlord.
Pay attention to dampness on walls, timber, carpet, furniture and fabrics and dry out or clean regularly to avoid mould accumulating.
Install dryers in the carport or verandah where possible. Ensure the dryer is safely installed and protected from the weather. Dryers installed inside should be vented to the outside where practical. Avoid using the dryer during the wet season and dry clothes in front of fans, on a verandah or in a well ventilated room. Condenser dryers that extract the water vapour from the air are a better choice for reducing condensation.
Keep bathroom doors closed when showering and run the fan before, during and after your shower to avoid a build-up of steam.
Run the fan before, during and after your shower
Installing insulation in walls will reduce condensation and mould build-up, and improve your home’s energy efficiency.
When painting, ensure you prepare and clean surfaces carefully to kill any existing mould. Select gloss or semi-gloss paints, as these repel mould more effectively than matt finishes. Mould-killing additives can be added to paints, grout and timber stains or select a primer or paints that have these already added.
To get rid of mould, a solution of 80% vinegar and 20% water on a microfibre cloth is the best approach. Thoroughly rinse the cloth at regular intervals to avoid spreading mould. While bleach can help reduce the appearance of mould, it’s ineffective at killing the spores. See this Choice guide for more tips.
Managing mould with your air conditioner
Operating an air conditioner in a sealed room dries the air as it cools it which can be effective in managing mould. When the inside temperature is lower than the outside temperature, switching off the air conditioner and opening windows lets humid air inside which may cause condensation to form. Keep the room closed until the inside temperature rises to the same as outside before opening it up to access breezes.
Condensation can lead to problems with mould
Condensation in apartments caused by differences between outdoor and indoor temperatures due to the operation of air conditioning can be a problem. For example, where a neighbour sets their air conditioner to a lower temperature overnight, cooling the slab floor or ceiling. If the air temperature is warmer inside your home this can allow condensation to form on the tiles, ceiling or metal studs in a plaster wall. You may need to speak to others in your building on how best to manage this situation.