ENERGY SAVING IN BUILDING – SOME PRACTICAL ASPECTS
INTRODUCTION

The consumption of energy in a building and its cost increases exponentially through out the entire life span of Building and it becomes a significant operational cost. The most common method for saving energy cost in such building consist of

  1. Improving efficiency of equipment.
  2. Eliminating energy use wherever possible.
  3. Use of Unconventional Energy.

ADMINISTRATION OF DAY LIGHTING

Poor designing of window give rise to glare and poor day light and so need of extra artificial lighting. Windows without proper sunshades do not distribute daylight evenly. The penetration of light into the building depends on the height of the window. More the height of the window, more will be the penetration of light into the building.

The light distribution can be improved by introductions of light shelf i.e. horizontal or tilted reflector surface next to a window that is capable of reflecting light on to the ceiling. Use of light colours for floor, walls, ceilings, furniture can also increase, day light condition of a building. A light colour to the external building can also be useful in increasing daylight.

Use of tinted glasses in windows and doors are becoming common to reduce glare caused by plain glasses. However these tinted glasses cut daylight.

In air-conditioned buildings good day lighting saves air conditioning load and also saves lighting load. Air conditioning load is reduced, as the heat component of artificial light is more than that of natural light & with more use of day – light the heat component is considerable reduced hence over all saving in cost.

The relative new concepts cropping up in day – lighting are

  1. Optical lighting
  2. Light pipes

The concept of optical lighting is to use mirrors and place them at the top of the building & reflect light into areas where daylight cannot reach in normal condition.

Light pipes are pipes capable of efficiently transmitting light along its length even if they are twisted and bent. This pipes are used in bunches and can reduce heat component of daylight.

ADMINISTRATION OF AIR CONDITION

With a rapid increase in living standards, the use of air conditioners is becoming very common these days. So a large proportion of energy is consumed for Air Conditioners. This energy consumption can be reduced by use of external shading of window, reflective external finishes, tight fitting door & window and use of cavity walls.

The load on Air Conditioners can be reduced by use of evaporative cooling as it requires very less energy as compared to air conditioner. Further cost saving can also be done by keeping a fan on and maintaining the room temperature at 27°C, instead of 23°C, without fan for air circulation.

ADMINISTRATION OF ARTIFICIAL LIGHTING

The efficiency of lighting depends on the following:

  1. Source i.e. the lamp and other fixture.
  2. The distribution and position of fixture.

  3. The reflectivity of different surfaces in office.

The type of source will depend on the illumination required and the period of time for which it is required. The most common source for general office is 40 watt fluorescent lamps. The mirror optic reflectors with bright finished cross louvers will increase the illumination.

A truth is that artificial lighting of building is done for black out conditions i.e. with no daylight in consideration. The office works during daytime. During this period it is not necessary to keep all these lights on, as some daylight is available.

A Right fixture for Right purpose at Right location with Right reflecting surface will reduce lighting load to a great extend.

Thus the consumption of energy can be reduced and thus its cost can also be significantly reduced.