Article written by Engr Arjumand Samad
Energy saved is better than energy produced. Considering the energy crisis it is wise to work on a strategy to spend less and save more. Energy conservation minimises the effects of global warming caused by the burning of fossil fuels for production of energy.
Also the soaring prices make it imperative to adopt energy smart living to minimise the burden of energy bills on our community. The umbrella of energy conservation and energy efficiency strategy can positively impact both economics and environment.
While planning to build a new home, one`s aim should be to create an energy smart, comfortable, aesthetically impressive and economically justified dwelling. This is achieved by first taking into account our environment and its challenges.
To develop such energy smart homes one should plan an architecture that suits our environment. This concept called “Green Living.” Energy smart homes are designed to get full benefit from the least possible resources but provide the same comfort and service as available in alternately designed housing.
Considering our climate ( i.e. temperate), where weather extremes are a must, a thermal envelop should be created around the house, that could isolate the home environment with the outside. To make this possible, the wall and the windows should be made leak proof; similarly the walls should be insulated to reduce heat absorption and to maintain comfortable temperature inside.
Good insulation of the walls and the ceilings /roofs is mandatory for an energy smart home. Also materials used in the construction should have low thermal mass which heats up slowly and cools down rapidly (e.g. fibre cement and weather board).
Using specially designed glass called solar E glass should be used in the windows instead of regular glass; this glass has the property of low solar heat gain and is also reflective at the same time. Similarly, tainted glass also reduces sun heats entering into the home. The efficiency of the windows not only depends upon the glass used but also on the frames and sashes being used. Good performing windows require high quality frames, two to three panes in co-operated with fibre glass envyingly frames are very energy efficient option.
Sun light should be made available into the homes by adding a feature of sky light into the roof where ever possible. These are available in glass and plastic material. Similarly, the cooling of the indoor environment of homes should be given prime importance while constructing the house.
The use of air-conditioners should be limited to areas that are small and going to be used extensively in the future, such as the bed rooms. This option is not energy-efficient and can be reduced by properly orienting the home, so breeze could easily flow into the house. Ceiling fans should be used for indoor circulation of air and small portable exhaust type fans can be positioned into the windows, to allow cooler air to flow into the house and warm air to be expelled out. This is only applicable in the evenings and the night times, still it greatly reduces electricity bills. A comfortable balance should be kept when designing a home with proper insulation and required ventilation.
Other than these practices, each home should be specifically tailored to the requirements of the future dwellers. Small additions while accessorising the house should be taken into account to, such as the height of the ceiling fan should be approximately seven to nine feet from the floor and from the ceiling it should be from 10 to12 inches below. Always the air-conditioning units should be kept under shades. This can be done by either providing trees on the exterior or placing an awning over the unit.
Landscaping for energy efficiency includes plantation of trees and other plants such as evergreen around the homes, that could reduced the cooling cost of the house. Paint the walls of the house with light colour as dark colours tend to absorb heat.
One should try to adjust the surrounding by adopting life styles and practices that would make the day-to-day life easy and also energy-efficient.
Technique should be adopted to optimise the use of sun`s energy in the day time and also use passive cooling technique into home that could cut energy bills and at the same time providing vitamin D, an element which is a prerequisite for human health. A comfortable balance should be created by incorporating energy smart tactics in designing homes that could maximise energy savings and minimise exorbitant energy cost.
The writer is Assistant Professor Electrical Department NED University of Engineering and Technology, Karachi.