🌇🎆💡💡ELECTRICAL SYSTEM💡💡🔌- indoor illumination continue💥⚡️✨🌟💫

Last week i started a discussion on illumination, for recap click here before you continue reading

There is an infinite range of room dimensions, but it has been found that the behavior of light in rooms is a function not of the room dimensions, but of the room index, which is the ratio of the area of the horizontal surfaces to that of vertical surfaces in the room.

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When considering the lumen which is the illumination method of design the vertical surfaces are measured from the working plane to the center of the fitting.

This is mathematically expressed as:

Room index = (Length x width)/ (Length + width)

Utilization Factor

Part of lumen output from the source is lost in the fitting. Some output is directed to the walls and ceilings where part will be absorbed and part reflected. Thus only a portion of the light reaches the working plane as explained above. This proportion is expressed as a number always less than unit.

Utilization factor clearly show that the light reaching the plane to illuminated is reduced so that the power of light source may have to be increased to achieve the desired value of illumination. The actual determination of coefficient of utilization calls for experience and judgement.

Maintenance Factor

Dust and dirt on fittings and sometimes agent of the fittings reduce the light output. Illuminations will also be impaired by deterioration in the condition of the decoration.

Maintenance Factors is sub divided into three major groups:

1.) slight soiling

2.) Normal soiling

3.) Heavy soiling.

Slight soiling is simply the type expressed in design offices while heavy soiling occur in blast furnace, mines and some textile factories.

Spacing Height Ratio

The correct mounting height of fittings is very important. Glare may result when they are in the line of vision, excessive height is bound to affect the illumination and make for problems in re-lamping and maintenance. Factories often have the fittings fixed at the roof trust or beam height. The value of the spacing-height ratio depends upon the type of fittings and the illumination, which may be specified. Once the height is decided, the ratio enables the spacing and therefore the number of fittings to be determined.

Source

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Glare

Glare is the excessive brightness in the field of vision. When the direct light fall directly to the eyes of the viewer it will make him or her have difficulty to see the object in view.

In their view, guiding against glare is very important and that why when installing fluorescent fitting it is advisable to install it with reflectors so as to be viewed cross-ways where bare tubes should lie long-ways.

In the next study I will be discussing on selection of switchgear

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