How To Save Power (And Money) Cooling Your Home In Summer

Temperatures expected to reach above 40 degrees in Sydney today, so here's some advice to keep you from melting into a puddle. It may be tempting to crank the air-con up high and keep your house at sub-arctic temperatures until the weather outside finally cools down, but it's worth thinking about the impact that's going to have on your bill. There are plenty of ways you can cool your house in a more economical way — or, if you can't bear turning off the air conditioner for a minute, we've collected a few tips so that you can use it more economically.

This post was originally published on November 6.

Gizmodo's Energy Smart Home series powered by Hello Grid — an initiative of the Energy Networks Association, representing the networks who deliver energy to almost all Australian homes and businesses.

Back To Basics

A house that keeps itself cool doesn't need a whole lot of expensive air-conditioning, so your first step in preparing for summer is making sure your house is up to scratch. A poorly insulated home can collect heat through the walls, windows, floor and even through air leaks, which can also be a source of draughts in the winter. The type of insulation your house will need will be dependent on its location, orientation and the climate. This government website has a full reference for the best type of insulation for regions across Australia, so have a look and make sure you're properly covered.

Of course, insulation has the potential to work against you in the summer if you don't keep the heat out to begin with. Heat coming in through windows and open doors can end up trapped in the house by the inner insulation layer designed to keep heat in in the winter. The best way to avoid this is to shade windows to make sure no sun is hitting the glass. This can be done with both fixed or adjustable shading like awnings, external shutters or blinds, louvres or just having sufficient width on your eaves to keep the sun from hitting your windows.

You can even consider planting more trees or shrubs to protect the most exposed parts of your house from the sun. The positioning and choice of shading will depend on the angle of the sun — which again depends on your orientation and the latitude of your house. Properly designed shading — like louvres — can be perfectly angled so that they let in as much winter sun as possible but block out most of the unwanted summer sun. The Your Home website gives a far more in depth explanation of utilising angles to block out as much sunlight as you can, depending on your house's particular needs.

No amount of shading and insulation is going to keep you perfectly cool by itself, but it will go a long way to reducing your energy usage — and your power bill. Every degree you lower your air conditioning could account for up to 10% of your electricity bill, so it's best to keep it around 24 to 25 degrees. Your air con may not be operating at full capacity if you haven't been taking care of it, so make sure that your filters are replaced regularly so that it doesn't have to use up more energy to cool the same amount of space. Speaking of space — there's no need to cool the rooms you're not using. Leave unused rooms closed off with the blinds down or curtains drawn to keep them as cool as possible while not straining your air con to cool a larger space.

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If it's not scorchingly hot, consider turning on a standing fan or a ceiling fan — compared to power-guzzling air conditioners, these can be run all day for just a handful of change. Even better, you can cool your house in summer without spending a cent on electricity — once the temperature starts to cool down in the evening, open a couple of windows or doors to get some airflow through the house. Make sure to open up your bedroom at this point as well, to make sure it's cooled down a bit so you can sleep without sweating out half your body weight.

Tricks and Gadgets

As mentioned before in our energy saving tips, home automation can be a huge help for anyone looking to cut their power bill with minimum effort. Most air conditioners will come with their own thermostat and likely some kind of timer or delayed start setting — but these often aren't the most user friendly systems for full automation. Luckily a number of companies are making smarter devices to help you cool your home.

Over in the US, the Nest Learning Thermostat is a smart thermostat equipped with a number of sensors that take most of the effort out of controlling your climate. Its sensors let it know when you are in the room or not, and the Nest adjusts the temperature accordingly — no use cooling a room you're not in, after all. It can all be controlled via mobile apps, although one of the features Nest sells itself on is the ability to learn your schedule and the temperatures you prefer so that it can begin to program itself. The Nest is made with a focus on sustainability, displaying a green leaf icon when you're within a temperature range that is energy efficient. "It guides you in the right direction," claims the Nest website.

Unfortunately, Nest isn't available directly in Australia — you can potentially import it from the USA, but it may take some adjustment to get it to work with our systems. Australia isn't without options, however. The Zen Thermostat is Australia's answer to the Nest. It doesn't program itself, but the Zen doesn't see this as a negative thing. In fact, the Zen markets itself as "the beautiful home thermostat that doesn't think it's smarter than you." They created a simple thermostat with a limited number of interfaces, but where the Zen is truly smart is its ability to integrate seamlessly with a number of existing home automation systems — including SwannOne, manufactured by the same company that created the Zen. With the Zen operating within a home automation system, you can set your air conditioning to run only when it needs to run. Instead of having the cold air blasting all night while you're asleep, schedule the system to turn off shortly after you go to bed.

Additionally, battery manufacturer Enphase's consumption monitoring system, Envoy, and its corresponding Enlighten software has just announced native support for Nest thermostats. "We can virtually hook their data stream to ours, so from what your thermostat is doing right now, MyEnlighten is able to add storage and solar technology to your thermostat controls," explained Enphase's Ilen Ilen Zazueta-Hall.

While this isn't as relevant to us here in Australia right now, Zazueta-Hall hopes that the future will bring more collaborations with creators of smart devices like this — maybe we'll even see integrations with Australia's Zen thermostat. With the coming rise in battery storage, there's no doubt that we'll see more examples of all these systems merging — where the amount of power your air conditioner uses may be automatically regulated depending on the amount of generated solar energy you have to spare.

New Dyson Hot + Cool Fan: Australian Review

Dyson’s Hot + Cool is motorised, heating and cooling behemoth that sucks air through a tiny aperture and accelerates it through the application of some nifty physics — just like a jet airliner’s turbofan. It’ll smoothly accelerate air from across a medium-sized room, and cool you at a distance while remaining quiet.

Load Control Programs

Coming back to the solutions we do have available today, there actually are programs that will automatically regulate your air conditioner's performance when energy conservation is important. These are programs created by the energy distributers themselves, to try and manage peak demand in times of high stress on the network — avoiding potentially uncomfortable mid-summer blackouts on unusually hot days.

When the weather goes past a certain temperature, the grid comes under strain as everyone cranks up their air con at once. This means extra money poured into infrastructure that is only used on a few days of the year when demand is high. In order to combat this peak strain, a number of electricity companies, including Endeavour Energy, Energex, Ausgrid and Ergon among others have instituted opt-in programs where you can allow them to remotely moderate your air conditioning unit's performance on these days.

In exchange for letting them control demand through your devices, most companies will give a rebate of some sort — as well as the bonus of helping to avoid summer blackouts. If you're unsure whether your energy company offers a rebate on a similar load control program, give them a ring and find out.

The options for cooling your house range from cheap to expensive, involved to hands off — and some are energy-saving habits that everyone should be doing on a daily basis anyway. Take the time now while the weather isn't yet scorching hot to make sure you're prepared for high summer — and if all else fails, it may be time to head to the beach.

The Five Biggest Myths About Saving Energy In The Summer

This summer is a hot one. With money tight and temperatures high, there’s a temptation to test out unconventional ways to beat the the heat. But these odd home remedies can end up wasting energy and costing more money. Here’s how to know what really works when you want to keep cool for cheap.


    A basic tip from someone in the tropics. Use the dry function on your aircon at night and avoid aircon use during the day. The hardest part of dealing with heat is using airconditioning.
    Yes using an aircon makes it harder to handle the heat and will make it feel hotter. My fiance and I both work outdoors and can both tell you about how if you're going into aircon outside is hell but if you stay out of aircon it doesn't get as hot. Also when it's 40 outside if you must use ac don't bother with 20 degrees, set your aircon as hot as it goes while still using its compressor. Our loungeroom aircon is set to 30c this time of year and it still feels crazy cool especially when it's 43c outside

      When I was young almost no one had air conditioning in their homes and so, not having a choice, we just quietly put up with it.

        Did you though? No one had air con when I was young and I can remember every complaining non stop all summer about the heat. Definitely can't remember anyone quietly putting up with it.

        Personally I'm happy to just use my ducted reverse cycle year round and be comfortable in my house. With a 5kw solar setup and a well insulated home I still only average around $250 a quarter, small price to pay in my opinion.

          Maybe it's because I grew up in the tropics and wasn't just a summer thing, but it had to be really, really hot before people complained about the heat. That said, I think if you can be comfortable, you should be. I don't hear people making a virtue out of being cold in winter. I think a lot of the hating on airconditioner use comes from it being a much more recent invention than heating and therefore a rarity/luxury in the past, and therefore being seen as an extravagance by some.

        We had these small evaporative units in legs, where you poured in a jug of water and it trickled down the back. Also ceiling fans. Then we got this in standalone Aircon with a house for the window. Then e got a spilt system in later years.

        So when I built my first house then and renovated another - an aircon went in straight away, cause it was hell not being able to sleep at night when younger.

        So to say we put up with it. No, we struggled. In the car was worse. Hot air blowing in your face from the non-aircon fan haha.

          I bought an evaporative system a couple of years ago, but in humid conditions it's almost completely ineffective.

          These days I live in a unit without aircon. I open the windows wide at night and close them in the morning. Pedestal fans located pointing at everywhere that I might want to sit down (and at my bed at night). There are still bad days, but it's mostly OK

    Great, but what do renters do? We have little to no control over things like insulation, garden landscape, or home automation, and trying to get owners to deal with even simple things like fixing pipes can be like pulling teeth.

    jaedee884's advice above is solid. My partner and I lived in Townsville for 3 years and found that air circulation is sometimes more effective and AC, because your body can get used to the heat, if it's in a consistently warm environment. Moving from a 18° air conditioned office to 40° heat with 98% humidity is a killer.

      I guess as a renter you have the option to move house with very little costs. So just look for a place that ticks all the boxes energy wise.

        Yeah I think thats the best bet. If you live somewhere where you'll have weather that keeps you uncomfortable in either summer or winter, make cooling or heating a priority when looking for rentals along with any other prerequisites (kitchen size, number of rooms, storage, car space etc).

        I wouldn't necessarily expect a landlord to want to spend money on such things if they can get tenants in without doing the work, and many of the solutions would be dead money if you could make them yourself. May as well just go into a place that meets the requirements from the outset.

        If I was in that position and can't move, I'd invest in some fans and try and get some circulation happening. If you have a patio, balcony or something I quite like those misting fans too.

          The trouble with the moving option is that a place that is better fitted out will probably cost more in extra rent than any savings you will get from the less energy-intensive temperature control. I think the best option is to just keep saving until you can buy your own place, and then you can make sure it's insulated properly and faces the right way.

            Thats a valid option too. Still, beats investing in upgrades to someone elses property and I don't think that owners should be required to retrofit cooling facilities once a person moves in (although existing ones should be maintained). Not to say anyone here is guilty of it, but some tenants seem to think it's a right to request things such as aircon be installed a few weeks after signing a lease, which I think is an absurd thing to demand and puts the owner well and truly out.

    I have found that setting a fan up to stationary instead of swivel is a good idea. I have one of those Vornado fans aimed at a wall and it forces the air to move in a single direction at all times.

      I second the Vornado fan. Those buggers can move some serious air.

    Get a tower fan. LIke the dyson one featured only cheaper. A decent one, which should be almost as tall as you when your standing next to it, will cost about $150-200.

    These blow out quite cool air and are much more efficient than a regular fan.

    Cool down your room in the early morning with the doors open (or using air con if you have to) and use the tower fan for the rest of the day.

    Even if you had several tower fans running, these use a maximum of about 40 watts of electricity, and that would be them on their highest setting. I find keeping them on the low or medium setting is enough for a nice cool breeze. So if you had 3 x tower fans in the same room, using 120 watts, that's about 5% of the power a typical reverse cycle air conditioner would use (which is over 2000 watts).

    I used my air con a lot to heat the room in winter, I live in Adelaide, but I haven't used it at all during this record-breaking October heat, and I don't plan to use it during summer at all (although i'm told it's best to give it a run at least once every few months)

      But a fan isn't active cooling, it's just blowing the air around. Granted, it does feel nicer when you are sweating to have air circulation to carry away the heat, but a fan in a closed room cannot decreased the temperature. (It will slightly increase it: that 40-120 Watts of electricity will become heat) If you use your air conditioner in "fan mode" it will use around the same amount of power without having to buy a separate fan.

      BTW, reverse cycle air conditioners are way more efficient for heating than other types of heaters. They don't just convert electricity into heat but actually bring in heat from outside. For every 1 of electricity they give you around 3-4 of heat!

        Ok so you've never used a tower fan then. Also I never disputed the efficiency of decent reverse cycle air-conditioning in winter, especially with tgethe newer inverter tech they have its great.

        Unless you live near the desert, you don't need a "active cooling" until you've had 3-4 days over 40 degrees, and in our coastal cities that most people live in, she doesn't get that hot mate.

          She doesn't get that hot - if you life in a double brick home you mean.

          Newer brick plaster homes heat up quickly, especially upstairs. If it's 25c outside it feels like 35c upstairs.

          That's why we went back to single storey.

          I live in Brisbane. Hot enough. Not as hot as Darwin or Townsville, granted.

          The desert is a dry heat so evaporative air conditioning works better than refrigerative air conditioning. I used to live in Toowoomba and that was the case.

      Fans don't blow out cool air. They blow out the same temperature air that they take in. :)

      Air that is moving, however, does give the illusion of being cooler due to the body's means of temperature regulation.

    A properly designed Australian house has the night rooms closer to the sunside... and the day rooms (living,kitchen) away from the sun. This makes the living areas cooler in summer and the bedrooms warmer for winter due to circulation.

    Counter to that it makes the bedrooms boiling hot during the summer day so avoid those rooms. A lot of people especially kids have there computers and electronic entertainment in the one room they should be avoiding in summer... move back to the family rooms.

    Our preferred strategy is to reduce heat in the roof space. During the day, no matter how good insulation is, some of that heat will radiate into the house. And during the night it just becomes a reservoir of unwanted energy that prevents the house cooling down.

    So we've had the roof painted with IR-reflective paint (radiates back around 40% of incident exposure). And we've had a number of vents installed to ensure that hot air can escape, especially in the evening. And soon we'll also have solar panels up there to shield the roof and absorb some of the sun's energy.

    Our take is it's best to try to reduce heat build-up rather than waste electricity counteracting what's already there.

      Also good to remember is insulation doesn't stop the heat getting in, it just slows down the heat trasferal. You'll often find the more north you go, the less insulation there is. Most people up here have power bills in the 2000s this time of year, whereas this time of year it goes to 900 rest of the year 600. (we have electric hot water and never turn it off along with my computer setup which has a small portable aircon cooling it 24/7)

      Do roof vents work? Whirly birds or vents in the eaves?


          The newer solar powered exhaust fans are move orders of magnitude more air so are a lot more effective; obviously more expensive as well.

    good place to start is to cover windows with aluminium foil. that alone drops temperatures! It attracts police as meth cooks do it as well. but they find out you have a genuine reason. drops temp a few degrees. so 38 degrees down to 32-34 degrees may be enough!

    and then if you do run air conditioners, having cooler in the house means its easier to attain 24-25 degrees (you shouldn't set temps to 18-21) the compressor never turns off and that is power hungry.

    You can also use mylar blankets. They are easier to put up & take down as needed, which is handy given how bad they look. You can also pin them between the lining and outer layer of curtains, they don't work quite as well when put up like this but they still make a difference.

    I bought a new inverter split system in the winter and it's been fantastic in the summer too.

    I cannot recommend envirotemp enough. It really works. I have my air con set at 28 degrees and it's very cool in the room, it feels like 20. It's great - oh and I have my fan speed on the lowest temperature too.

    My inverter with envirotemp has been so good I have now purchased another one for my bedroom. I use Panasonic which also has the econonavi feature to further reduce electricity use. It really works. My AC use barely adds $10 a month to my electricity bill.

    Sometimes if I come home to a really hot house I will set the fan to auto and let the unit cool it down faster, then slow it down, but normally I find the lowest fan speed the best.

    I try to open windows and doors in the early morning and evening to cool down the house where possible, but once you get 2 or 3 35+ degree days it's just too hot to do that. Same in winter, you can't warm a house when it's been 13 degrees for 5 days in a row.

    So yes I am a bit of a hypocrite for the comments I wrote months ago (on this same story) but you know people have the right to change their minds.

    Last edited 24/12/15 2:44 pm

    And here i am with my makeshift aircon using an esky, fan and a few bags of ice

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