Sustainable home, Mr Cheyne.
In Australia, 38% percent of the electricity bill is used for heating and cooling. In order to make a sustainable home there are considerations that need to be made.
Insulation is a method used for cooling or heating and can reduce the heat by about 6 degrees celsius. The best type of insulation is fibreglass batts, which are 150 millimetres thick and are laid on the inside of the ceiling, beneath the roof. The air pockets in the insulation medium of the batts make for a very poor conductor and therefore provide excellent heat insulation. The fibreglass sits on the ceiling of the house and not the roofing, which means that the heat can not go through into the house like it would if the insulation was on the beams. When the roofing heats up inside, they have ventilators which allow for cold air to be sucked in from the bottom and the hot air to be let out of the highest point in the ceiling creating convection. The reason we use insulation is because it keeps us cool in summer and warm in winter.
How will you design your garden to incorporate shade? The house should also have deciduous trees placed around it which will allow for sun to come through in winter and the sun to be blocked in summer. Outer blinds could also be placed so that some of the radiant heat can be blocked. The house should also be placed in a position so that the wind can be caught, that will allow for a free cool breeze to flow through your house.
What will you use for electricity? What type of electrical appliances will you use?The appliances that you use in your house also have an effect on your energy use. For example a traditional light bulb is 90% heat and 10% light, compared to a light emitting diode (LED) light which is 70% light and 30% heat and is a lot more bright too. The amount of time you spend in the shower and the temperature that you have it at also has an impact on the electricity bill, because you need to heat the water in order to have a hot shower. On top of the roof you could install solar power. This is a renewable energy and you will save on your power bill.
How will you make your home water-efficient?Making a sustainable home also includes using less water. Utilising water efficient shower heads and taps will minimize the outlet of water, and therefore decrease the overall water usage of the home.
How will you allow for convection and air flow?When the energy efficient air conditioning units are installed into the house they should be put on the top part of the wall, allowing for convection to occur, with the cool air sinking and the hot air rising. The air-conditioning unit that would be most efficient is a split inverter, operating a single motor system for a multi-head unit. The inverter system in comparison to the traditional system is much more energy efficient, with each internal vent being operated by the single motor, therefore utilizing less energy.
How will you orientate your house? (remember we live in the southern hemisphere)The direction that the house is facing can effect how hot it gets. When designing it, the living room should be positioned facing north and those windows should be placed in the direction that the winter light shines through, so and in summer it won’t. This is because in winter the sun shines lower and in summer the sun shines higher. The house could also have blinds on the outside to prevent some of the radiant heat reaching the glass and heating the house, therefore making the air conditioning more efficient as well.