A short newsletter giving practical advice on minimising your energy for heating and cooling focusing on low cost easily implemented ideas.
For full details visit http://www.coolmax.com.au
How can you reduce your heat load for as little as $10?
Will the latest changes to the building regulations reduce energy demand?
How to minimise the biggest energy villain in modern houses?
As you can see below the biggest energy villain in modern houses are the windows. A cheap way to reduce the solar heat gain from them is to use outside matchstick or bamboo blinds. For small windows you can buy them for under $10. Larger windows cost more, but they are still affordable. Put them on your west facing windows first, then your east windows. In Southern Australia you shouldn't need them on the south windows, and if you have a small eave on your north windows you won't need them there.Back to Contents
The short answer is yes if they are enforced. Most states have recently introduced tougher requirements to get building approval. In most cases if buildings are built to the new requirements, you will:
What is the downside? Buildings may cost slightly more but the energy savings should exceed the extra interest payments. In fact I believe that once architects start designing to meet the requirements as an integral part of the design, rather than tacking on additions to meet the requirements, the cost difference will be negligible.
Another potential issue is enforcement of the requirements. If the building built doesn't include the features used to achieve the rating and submitted to council, then the whole benefit will be lost. This is something we will have to be diligent about and take action if we see failures to comply.
The other big issue is that these regulations don't address the existing building stock. The bulk of households will for decades to come still be living in existing buildings. Unless the faults in these buildings are rectified, our energy use will continue to be unacceptable. Of course, by reading this newsletter (and hopefully adopting some of the ideas) you are addressing this problem!Back to Contents
The biggest energy villain in modern houses is the windows. We have built houses with walls of glass facing west and wondered why they are impossible to air condition. During the colder months the thin glass cools the layer of air next to it which then sinks to the floor and freezes your toes. We wouldn't expect an uninsulated galvanised lean-to to be comfortable in summer or winter, but we build rooms of glass which are even worse in summer. (You might think that glass is a better insulator than steel, which it is, but 4 or even 6mm glass has negligible resistance to heat. For a single thickness of glass to give a useful amount of thermal resistance you would want it to be at least 300mm thick!
Well you can now see the problem, but what is the solution? The first task is to be judicious in your use of windows if building a new building or extending. Your state government energy office will have plenty of good advice on this.
The second task is to keep the sun off the glass during summer. Generally on the north windows, an eave approximately half as wide as the window is high will do the trick. On West and east windows you can use trees (see CoolComfort issue 1), wide pergolas or external blinds. The quickest and cheapest is often blinds see above. South windows don't generally pose a problem as the sun is usually fairly low by the time it has travelled far enough south. However if the house is at a slight angle to South you may have a problem first thing in the morning or in the evening. Planting appropriate shrubs or trees should fix this.
The third task is to increase the effective insulation value. The options are:
Clive Blanchard, Consulting Mechanical Engineer
78 West St
South AUSTRALIA, AUSTRALIA 5031
Web page: http://www.coolmax.com.au
Phone (08) 8354 1062