The climate of your area significantly impacts your air conditioning needs. For instance, in Adelaide, where the climate can be both hot in summer and cold in winter, opting for an air conditioning unit with effective heating capabilities is essential. A reverse cycle unit (heat pump) can help minimize energy use, as more energy will likely be used for heating during the colder months than cooling in the hotter months.

Portable air conditioners are a good option for renters or those needing a temporary solution. They are easy to install and can theoretically be moved from room to room (although in practice because you need a vent kit and where you put it is where it will stay). However, they are generally less efficient and powerful than other systems, making them suitable for small spaces or occasional use. They are more effective in the evening and at night.

As one salesman I knew would say:
'What have you got now?' 
The answer would be 'Nothing'
His response would be 'Well this is better than nothing.' 
In other words, only choose a portable air conditioner if it is the only option. 

If buying an air conditioner, you need to consider the energy efficiency as the running costs will exceed the purchase cost after a few years. Check the star rating on the government web site Energy Rating - Air Conditioners - AS/NZS 3823.2 .
Generally you should choose the best heating star rating you can afford and aim for at least 3-stars heating, even if you are actually purchasing it primarily for cooling as you will use more energy for heating than cooling.
It is important to choose the correct star rating as air conditioners assessed to the old rating will appear to have a higher star rating. If you are in Adelaide compare the ‘SEER Heating Star Rating’ for the ‘mixed zone’ see below.

Setting the thermostat correctly is critical to achieving comfort and minimising energy use. Setting the Temperature one-degree cooler than needed in the summer will cause a surprisingly large increase in energy use. Similarly setting the Temperature one-degree warmer than needed in the winter will also cause a surprisingly large increase in energy use.

Some old-style thermostats have a single temperature setting, and the temperature swings around that setting. Most modern ones have separate heating and cooling settings, which allow closer control. Normally it is best to set the temperature at 22 degrees for a single setting thermostat or at 20º for heating and 24º for cooling (possibly higher if you have ceiling fans) with a dual setting thermostat. For most air conditioners this would give a temperature of around 24 degrees for most of the summer and 20 degrees for most of the winter. If you can achieve comfort at a higher temperature in summer, or a lower temperature in winter, use the higher summer setting or lower winter setting as every degree change can save up to 10% of your heating or cooling energy.

In practice there are several factors that may require a different setting. For example, if in winter you get freezing air next to the windows sinking down and pooling at floor level, it may be necessary to set the thermostat at a higher temperature (although a better long-term solution would be to have honeycomb blinds or thick drapes with a pelmet to reduce the heat loss). To find out what the best solution is, it may be worth getting an energy audit as getting the right solution would save a lot more than the cost of the audit.

Often thermostats are not very accurate; this is not really a problem if you can find a single setting that achieves comfort all year round. However, it is probably necessary to occasionally tweak the setting.

You can find a suitable setting by randomly adjusting the thermostat, but if that doesn't seem to work, try the following approach:
1.On a day that is warm (to find the best summer setting) or cool (to find the best winter setting), but not an extremely hot or cold day.
2.Ensure the air conditioner has been running for at least one hour so the temperature is stable.
3.Initially set the thermostat to 22 degrees (for a single setting thermostat) or 24 degrees if you are setting cooling on a dual setting thermostat, or 20 degrees if setting heating on a dual setting thermostat.
4.Wait for a period of time (at least 10-15 minutes) to allow the air conditioner to stabilise again
5.If this hasn’t achieved comfort, set the thermostat slightly higher or lower, as seems appropriate. Don’t adjust it by more than a degree at a time or you will end up overcorrecting and take longer to find the best setting.

In summer, using ceiling fans may enable you to set the thermostat slightly higher. It will also significantly reduce the number of hours you need to operate the air conditioner.

Remember there are some problems that can’t be fixed by adjusting the thermostat. For example, if the air conditioner doesn’t have enough capacity due to the temperature of the day, adjusting the set point won’t make any difference to the room temperature. If this is the case, start with Cleaning Filters below, also see the blog post Our house is too hot, what can I do? Setting the thermostat also can't generally cure hot and cold spots, (refer Hot and Cold Spots below).
​
A future post will address basic troubleshooting of an air conditioner.

Some homes have hot and cold spots, usually caused by an air conditioner serving areas that have windows facing different directions, or the difference between the old and new parts of a home.
It is possible to get ducted air conditioning controllers to give individual temperature control in each room, however this is still quite expensive. Most people must use judicious control of curtains or blinds to control temperature differences.
To save randomly trying different ideas, it may be worth getting an energy audit as getting the right solution first off, would likely save a lot more than the cost of the audit.

To keep informed of my latest posts, sign up for the Energy Saving Newsletter and as a free bonus, get  a 14 page extract from the forthcoming second edition of the book:

'House Taming, How to reduce greenhouse gases in comfort'

Sign up now to the Energy Saving Newsletter.

If you need personalised advice or you are thinking of spending some real money on air conditioning or improvements to the house, get an energy audit. I guarantee I can cost effectively save you the cost of the audit or the audit is free.

Feel free to leave a comment or question below.

In my last post (Wondering why you have trouble sleeping lately?) I promised I would write about creating a heat refuge (sometimes called a cool refuge) in your home for those exceptional hot nights where it doesn’t cool down enough to sleep.

Given that more hot weather is forecast, I thought I would finish it early to give you a chance to at least take the first steps.

With summer nighttime minimum temperatures increasing even faster than daytime temperatures creating a home heat refuge is desirable in much of Australia, especially during extreme weather conditions.

The blackouts in various parts of Australia, show that even if you have ducted air conditioning, when the grid goes down, unless your house is well insulated, the inside temperature can rise quickly to dangerous temperatures.

Ideally you would upgrade your whole house, using a Residential Efficiency Scorecard or an EnerPHit Passive House assessment for guidance.

As an alternative, when doing a Scorecard or EnerPHit assessment I can at no extra cost help you identify a room to serve as a home heat refuge, which in cold weather can double as a cold refuge as many improvements will target both. This is a lot cheaper than upgrading your whole house.
Even if you can’t afford that, the following low-cost ideas could get you started to create a refuge in one room to make your life safer and more comfortable during heatwaves: Most of them will also double for protecting you from cold snaps in winter.

These ideas should be read in conjunction with Wondering why you have trouble sleeping lately?

This should ideally be a room that:

• Is naturally reasonably cool.
• Is large enough to shelter all the home’s occupants.
• Can be isolated from other parts of the house by closing doors.
• A room where you can create good cross ventilation, once it is cooler outside .
• A room that you spend a reasonable amount of time in.
• If you already have air conditioning in one room, that may be a good option if it is large enough.
• Depending on your family situation, a bedroom or lounge are often good options.

​

• Plant trees or install outdoor shades (such as pergolas or awnings) on windows that get direct sunlight, to provide natural shade and reduce heat absorption.
• If that is not feasible, consider getting some shade cloth or spare fabric and fixing it outside the window to keep the heat off. This is more effective at keeping the room cool than internal blinds or curtains, although both are worthwhile, and the combination is even better.
• Use curtains or blinds to block direct sunlight during the hottest parts of the day. Light-coloured curtain backings can reflect heat away from your home.
• If you can afford it consider high performance windows, add on double glazing or window films.

• Ensure the room has comfortable seating, water, room to sleep in and any necessary medications.
• Minimise electrical and other sources of heat in the room. For example if you need medications kept cool and to cool the water, ideally use a fridge located in another room.

• Ensure the room has LED lights not halogen.

Remember that creating a heat refuge is not only about physical comfort but also about protecting your health. If your home lacks proper cooling, consider finding local facilities (such as shopping centres, libraries or swimming pools) that can serve as cooling refuges during extreme heatwaves.

Stay safe and take care!

To keep informed of my latest posts, sign up for the Energy Saving Newsletter and as a free bonus, get  a 14 page extract from the forthcoming second edition of the book:

'House Taming, How to reduce greenhouse gases in comfort'

Sign up now to the Energy Saving Newsletter.

If you need personalised advice or you are thinking on spending some real money on the refuge, get an energy audit. I guarantee I can cost effectively save you the cost of the audit.

Feel free to leave a comment or question below.

It might not just be you.

In Adelaide the Bureau of Meteorology forecast overnight minima for this summer are significantly above the historical median. 

Sarah Perkins-Kirkpatrick from the University of NSW says that since the mid 50”s overnight minima have been rising faster than daytime maxima.

What this means is that in most of southern Australia and in particular the Adelaide plains, the number of nights that the temperature outside doesn’t drop to sleep temperatures has increased and is likely to continue to increase.

This also means your house doesn’t cool down overnight and if the next day is also hot, the house continues to get even hotter.

​So, what should you do if it is a stinking hot night?

If you have an air conditioner, make sure it is performing as well as possible, see Help, my air conditioner isn't performing!

​

• Make sure you are hydrated so that your body can use evaporation to keep you cool.
• Sleep in the coolest room in the house, drag your mattress there.
• Use your air-conditioner if you have one and if you also have ceiling fans in the same room use them as well. (More on getting the best from air-conditioning in a future post.)
• If you don’t have a ceiling fan, buy a pedestal fan. They are less than $100 and cheap ones are $25 or less from Woolworths or Bunnings.
• As soon as it is cooler outside than in, open all your windows except in rooms with an air conditioner running. (If you have an evaporative cooler, you will have opened the windows sufficient to allow the air to exhaust. Note that it can feel cooler outside even if it is actually hotter. So, if you can, use actual temperature measurements, an indoor/outdoor thermometer (Bunnings sell one for under $25). Alternatively, you can use an old-style thermometer (less than $5) and compare it to your weather App. Note, use the actual temperature, not the ‘Feels Like” temperature.
• When using outside ventilation, if possible, open doors between rooms to get a cross flow of air from one side of the house to the other. This is much more effective than simply opening a window in one room. If you need to keep a pet out, consider temporarily putting a pet height barrier, so you can allow the cross ventilation. (Baby barriers sometimes work.)
• If it is hotter outside close the windows, and all blinds and curtains. If you wake up in the middle of the night, recheck the temperatures as it may have cooled down enough to allow a cooling breeze.
• Minimise heat build-up during the day. If the sun is shining on a window, shade the window, if you have external blinds pull them down, If not consider getting some shade cloth or spare fabric and fixing it outside the window to keep the heat off.
• Take a cool shower or bath before bed and if you wake up and can’t go back to sleep.
• Try a wet cloth draped over you.
• Wear minimal lightweight bedclothes.
• For the longer term consider turning a room into a heat refuge (sometimes called a cool refuge). This is a big topic and I address it in a separate post: Our house is too hot what can I do?
• Get a home energy audit to find out what is critical for your home and location.

​To keep informed of my latest posts, sign up for the Energy Saving Newsletter and as a free bonus, get  a 14 page extract from the forthcoming second edition of the book:

'House Taming, How to reduce greenhouse gases in comfort'

Sign up now to the Energy Saving Newsletter.

If you need personalised advice or you are thinking on spending some real money on the refuge, get an energy audit. I guarantee I can cost effectively save you the cost of the audit.

Feel free to leave a comment or question below.

Have you just received your latest energy bill and been shocked?

Bills have typically gone up 20-25%, but many who were on good deals have found their discounts cut heavily and for these people the increase is often even more (up to 40%)!
​
Well, what can you do about it?

If you google for example ‘reduce energy bills’ you will get pages and pages of energy saving ideas, but are they relevant to you? Some will be relevant, but most won’t be (or will have a miniscule impact).
​
There is no silver bullet, and whatever you do it is going to have to be a combination of savings in different areas. But as an example, our total energy cost for this year was less than $135. Yes, that’s right, $135 for the year!

Now that took many years and there are reasons I could cost effectively reduce my energy use that low. However I can make a dramatic difference to your energy costs. see Energy Audits.

Whether an idea will work for you depends on:

• The size of your bill
• Your cost of energy
• Where you live
• House design
• How you operate your home
• The number of people in your home
• Whether you are at home on most days

​But how do these affect your energy costs?

The first thing is to understand what is using your electricity and gas.

The chart shows typical household energy use; however, you aren’t the average person and your use could vary dramatically (up or down) from the pie chart. Hence you really need tailored advice.

Anything requiring heating or cooling for an extended period is likely to contribute significantly to your energy costs.

For example, room heating and cooling are usually the biggest single energy users for most people. On average, 40% of home energy use but it could range from less than 20% to over 70%. Especially if you have whole of house heating or cooling this should be a big focus for your energy saving efforts. surprisingly, for most Southern Australians, Heating is a bigger energy demand than cooling. See also More on keeping warm 

Another big item is hot water, typically 25% of energy use.

Appliances are typically around 30% of energy use. However, if you have a spa or swimming pool it could be much larger.

If you have LED lights, lighting energy use is quite small. (If you don’t, it is worth only buying LED replacement globes where feasible.) If you have halogen downlights, that is a complicated problem, which will need to be the subject of a future post.​