12. 1. Day Light
Advantages
• It is Natural and free of cost
• It is soothing and does not cause
fatigue to the eyes.
• Daylight intensity changes
during the day and it provides
another dimension to room
which is refreshing
Disadvantages
• The changing intensity of light can change
the atmosphere of the room
• direct sunlight can fade some color of the
fabric
• daylight do not evenly illuminate a room
• supplementary lighting is required as the
intensity of daylight is not the same
throughout the day
• large window designed for daylight can
make a room extremely hot or cold
during summer and winter respectively
14. Types of fixtures used
• 1. Filament bulbs –they are easy to install add an amount of light that can be changed by simply
changing the bulb. But these bulbs are not of uniform quality and require additional crew fitting
• 2. Florescent tubes –they are also referred to as strip light. These are of two types :
• Cold cathode tube –They light up immediately without flickering.
• Hot cathode tube –Require flickering before starting
23. Translucent Lighting-The light source
is concealed under the panel which
may be on the floor or the ceiling or a
free-standing decorative unit. These
are used in discotheques, kitchens,
bathrooms, or other work areas
24. Track Lighting-These are lighting fixtures fitted on the track. This may be
used to throw light to highlight the wall or the contents of the wall.
25. Factors to Consider when Planning a Lighting
System
• 1. The amount of light required for an area will depend on various factors like:
• Location and direction of the light sources.
• Reflected qualities of color.
• Textures used in the room.
• The number of lamps and fixtures.
• The wattage of bulbs and tubes.
• 2. If artificially lighting a room check on heat gains.
• 3. Design and durability.
• 4. Ease of replacement especially if lampshades are used.
• 5. Cleaning-they should be easily cleaned.
• 6. Cost.
26. Recommended
Value of
Illumination
General Labs- 400 Lux
Reading Tables- 600 Lux
Bars- 50-70 Lux
Kitchens- 200 Lux
Restaurant Tables- 100 Lux
Bedroom- 100 Lux
Hospital Wards- 50 Lux
Stairs and Corridors- 100 Lux
27. Principles of
Lighting
Designs
• The use of lighting is visually pleasing when it follows the following principles:
• 1. Balance: This is achieved by placing light sources throughout the room avoiding a
concentration of light on any side or area of the space. Balance can be symmetrical or
asymmetrical.
• 2. Unity: This can be achieved by duplicating the fixtures as well as repeating the materials,
finishes, colours, textures, and maybe lampshades.
• 3. Variety: This can be created by using similar but not identical fixtures. Variety can also be
created by having general and local lighting also by changing the level of illumination
• with dimmers.
• 4. Emphasis: It is given by highlighting. Lack of emphasis in an interior causes boredom,
confusion, and uncertainty as to the design content and intention.
• 5. Rhythm: The sequence of lighting will create a luminous rhythm giving the space a
dynamic quality.
• 6. Scale and Proportion: The fixtures must be in proportion and scale to the room,
themselves, and to the relative objects in the room.
• 7. Harmony: If the contrast between general and accent lighting is too strong there will not
be enough luminous transaction and the lighting composition will lack harmony
