Design Principle – 2: Consider Energy requirement as a primary function.
The next principle that I would like discuss is considering the energy requirement as a primary function of design.
When we think of buying a car probably the first question that pops up in the mind is the ‘mileage’ that we would get. Why is that? This is because we understand that the cost of owning the car for the next 3 to 5 years would greatly depend on the cost of the fuel that we would use in running the car.
But do we ask the same question when we think of buying a house or a flat? Probably not! We don’t ask “What is the energy requirement per square foot?” But we would probably own this building for the next few decades and we would certainly consume a lot of energy in the process, which unfortunately has to be paid for. This important question is yet to pop up in the social consciousness.
Nowadays there is a lot of talk about carbon emission and carbon footprint. In simple terms it means that more energy (fossil fuel based) more the carbon we emit into the environment (carbon footprint). Statistics show that 50% of the global carbon footprint comes is generated from buildings and 20% of the global footprint is generated by automobiles. Once we know this designers would become more alert about the energy per unit. And this would save users a lot of money.
There is another interesting statistics. In India we consume 2.88 times as much energy to produce one unit of GDP as it does in the west or for that matter in other developed nations.
What does that mean? It means that manufacturing industries in India are at a severe competitive disadvantage when compared to their peers. It also means that it is time that we wake up and do something constructive. However, it is also clear that energy savings would not be achieved by putting up signboards asking people to ‘switch off’ electrical appliances when not needed. The solution lies in Design and Maintenance. We can design things in such a manner that we can reduce the requirement as much as possible and use whatever is available to the best possible advantage and maintain things in such a way that energy consumption is minimized and sustained.
Let us illustrate the point with examples.
Modern air conditioners have redesigned the heat exchanger tubes in such a way (fluted inside) that the energy exchange is maximized through extended surface area and by inducing chaotic flows. This lowers the energy needed for cooling. Present day Godrej air conditioners serve as an example.
Modern air conditioners manufacturers have also introduced a variable speed electric motor that never actually stops and starts frequently and consume extra energy in the process. These motors run continuously — though at a very low speed when the desired temperature is achieved. As we know that electrical consumption of motor is proportional to the square of the speed. So the electric power consumption is saved in two distinct ways — a) avoiding surge currents during starts and b) lowering of the speed when not needed and by maintaining a steady state temperature distribution.
By using natural light and wind we may not only improve the environment inside offices and factories but also reduce the electrical consumption to a great extent that would have otherwise been used up to heat or cool work spaces. A small example, that might be in order, is to minimize the use of glasses in a tropical climate. We use such concepts extensively while designing modern work spaces.
Cleaning heat exchangers and condensers is a simple and effective way to reduce energy losses on the whole.
Proper lubrication of gear boxes can bring down the energy losses by as much as 5 to 10%.
Lastly using solar power and proper insulation of pipes, floors, roofs and maintaining them in good order are other cheap and effective ways to reduce carbon footprints.
These examples hopefully, illustrate that there are so many ways in which Design and Maintenance can help us to reduce the ever increasing carbon footprint and make our world more sustainable and habitable.
Hence taking energy requirement as a primary design challenge and function is extremely important and all the more important in today’s context. It is therefore a basic principle of design and maintenance (design and maintenance are just inverted images of each other — both serving the same purpose).