Josh Jennings December 10, 2011
There are other ways to keep cool this summer besides cranking up the aircon.
Intrinsic to whether Australians look forward to summer or dread it is how well they can control the temperature inside their home.
According to the PricewaterhouseCoopers report Protecting Human Health and Safety During Severe and Extreme Heat Events, which was released last month, heat has claimed the lives of more Australians over the past 200 years than any other natural disaster.
But the report says there's plenty people can do to their homes to reduce the adverse effects of hot weather. Here are seven tips to keep you cool.
Multiple windows/doors open in a room allows air to move freely. Ausgrid energy efficiency expert Paul Myor says the effectiveness of cross ventilation depends on the home type and its location (how many cool breezes does the area have in summer?) but rule number one is to be sure the temperature outside is cooler than the temperature inside.
Mr Myor says those who are designing a house from scratch are in the best position to make cross ventilation work by choosing a design that opens the house to breezes.
That's not to say existing home owners can't make it work.
''If there's any kind of cooling breeze in summer, why not open opposite sides of your home, whether it's doors or windows, to let that breeze go through it?
''I don't think it's a particularly difficult one to do for homes.''
Mr Myor says various factors will affect the cost of insulation but you can generally expect to pay about $1200 to $1500 to have it installed in the ceiling. That's not so bad, given that it might last for decades, Mr Myor says.
''And it does have the potential to reduce the heat gain of a home by as much as 30 per cent … and potentially reduce temperatures by more than five degrees.''
Getting it installed does require some legwork, however.
''I would expect an installer could do a typical house in a day but you'd have to plan ahead …
''It's not something you will arrange in a day or two; it would probably take a few weeks of planning to get done.''
Figures from savelight.com.au show LED lighting uses more than 60 per cent less heat than traditional halogen globes. A sustainability consultant with energy assessment and audit services company Ecovantage, Nick Balgue, says while light globes are commonly overlooked as heat generators, the impact they have is proportionate to the number you have.
''Most places will have about 30 to 40 halogen lights in their home and they can really heat up a house,'' he says.
But there are costs to consider in switching to better globes.
''People pay less than $5 for a halogen globe, whereas the LEDs can range from $30 to $100 (though the pay-off is in the drastically greater durability of LEDs),'' Mr Balgue says.
''So if you have 30 in your home, it's quite a big outlay.
''It will depend on how often people use them but it could take up to 10 years to pay off.''
However, LEDs could also mean more comfortable summer living.
Ovens, dishwashers and dryers all generate heat. TVs and computer monitors generate heat too. The potential combined effect of all these household appliances on household temperature can be considerable, Mr Balgue says.
''If someone's been cooking all day, obviously the house is going to be significantly warmer.
''You could be looking at a 2 to 5-degree increase if everything is on,'' he says. ''So if you're using an airconditioner, you're going to have to turn it up more.''
Better management of household appliances might be common sense but that doesn't mean everyone will, Mr Balgue adds.
Mr Myor says shading windows, particularly with external blinds or shades, is one of the most effective steps people can take to stave off the summer heat. But it's not particularly quick or easy to organise.
''We're not talking about a simple behaviour change,'' Mr Myor says; it will take planning and money. However, there are long-term benefits to consider.
''Each square metre of direct sun you have coming through a window in summer is like running a one-bar radiator or electric heater inside your home,'' he says.
''So given that external shades on windows might last 10 or 20 years, I do think you would get quite a good return on your investment in just having a more comfortable home and one you probably wouldn't have to aircondition as much.''
Mr Myor says when air is moving across us, the temperature seems about three degrees lower. He says pedestal fans can cost about $30.
''Pedestal fans are an easy option and you can move them from one room to another.''
Ceiling fans are a different prospect, Mr Myor says, because you need an electrician to install them.
''But the potential benefits are there … We want to help people understand how much less electricity a fan uses compared with an airconditioner, because I don't think the average person understands that too well.
''A ceiling fan might cost one or two cents an hour to run, whereas an airconditioner could be 35 or 40 cents an hour.''
A fan might not cut it on an extreme heat day but it could do the trick for a much smaller cost on milder summer days, Mr Myor says.
''If it's a 28-degree day … it might be that those fans are enough for people to be comfortable in their living areas,'' he says. ''But fans won't give you the climate control an airconditioner can - simple as that. An airconditioner can drop the temperature of a room and de-humidify the air … But you need to keep in mind that airconditioners are expensive to install and can be expensive to run - depending on how you use them.''
A Master Builders Association of Victoria sustainable building adviser, Dr Phil Alviano, says reflective coatings on windows are a cheaper alternative to external shading devices such as awnings and are best suited to east and west-facing windows, where the sun sits low in the sky.
''The issue for most people is going to be how that's going to affect their view looking out and the colour of the light inside the house.''
Their effectiveness will depend on the quality of the installation, too, Dr Alviano says.
''There's a bunch of stuff that you can install yourself that will be quite effective but it might not look so nice on the window.
''A professional installation will certainly look better on the window but you want to decide whether you want to do it yourself or get a professional to do it.
''This will obviously start affecting the cost,'' Dr Alviano says.