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 recent power blackouts in Victoria 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) 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.
• 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 March to May is for a 76% chance that it is above the historical median and 38% chance of it being unusually warm.

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.
• 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.

If 10% of the ceiling is bare due to insulation being tossed aside or being incomplete, the heat loss can double.

I have rarely gone into a roof space (even a new one) and found the insulation properly distributed. Since I have bought a thermal imager, I have not found a ceiling without an insulation fault of some sort.

The most common issue is ceiling batts tossed aside by a tradesman and not replaced. (Although there are many good tradies, there are too many electricians, air conditioning installers and plumbers who don’t make a habit of checking that the insulation has been returned to the correct place after they have finished their work). If you are employing someone who will be working in the roof space, let them know that any insulation that needs to be removed, needs to be replaced properly (for example trimmed around a fan)

Some of the worst examples of failure to replace insulation occur with down lights. If you have down lights you might have a dozen in the room and if a ceiling batt is tossed aside at each light, you would have 12 displaced ceiling batts, which may well more than double the heat loss or gain through the ceiling.

Often this can be readily improved if this is in an attic roof space. Do bear in mind that depending on the type of downlight you may need to give a gap, which depending on the light and insulation may need to be up to 100mm clear around the light. Check the make and model of the downlight to determine the clearance required.

Although I prefer surface or pendant lights to downlights, some of them, particularly the newer LED downlights can be safely covered with insulation, however check the manufacturer's instructions.

Another common issue is ceiling fans. they need a clearance around them to avoid jamming the blades, but often a whole batt is tossed aside. Ideally the ceiling fan should be a ducted fan and discharged above the roof. If the ceiling space is well vented, e.g. an un-sarked tile roof, depending on your climate you may get away with it discharging into the roof until you replace it. However, it is preferable to install a DraftStoppa  so that you can safely insulate to the DraftStoppa and also so that when the fan is not working you don't get air leakage and lose the heat or cool in your house.

When improving the insulation, gaps in the insulation, for example around framing timbers or at edges, should be filled with offcuts.
 
Insulation that has been wetted or compressed doesn’t perform as well as it should and should be replaced.

Manhole covers are often uninsulated. Gluing insulation using a construction adhesive (Liquid Nails) to the top of the cover, will reduce heat loss to the roof.

Another issue with insulation is often the extent is insufficient.  Ideally the insulation should extend over the top of the walls. 

If you intend doing the insulation yourself there are a number of considerations:

• Downlights may need clearance to avoid overheating (check the manufacturers recommendations for the model)
• Fans opening direct to the ceiling space need a DraftStoppa so you can insulate directly up to them.
• As with any DIY project, consider safety, e.g. safe access, don't work in the roof space in the heat of a summer afternoon etc.

Insulation can be installed deeper than the ceiling joists, however you need to:

• ensure you don't cover electrical cables unless an electrician has confirmed that the cable is safe (cables clipped to the structure can have the insulation butting up against it, if it is modern wiring.) If there is any doubt, get it checked by an electrician.
• consider whether it is safe to move about the ceiling space. If there are appliances in the ceiling (air conditioners, hot water services etc., consider installing permanent crawl boards for safe access.) 

If you are planning on increasing the insulation thickness, I suggest you consider creating a plan to ensure you achieve an optimum insulation level and consider what options you should do when. See Energy Audits.