Lighting load is significant for residential, commercial or industrial building or spaces. Windows enlarging and providing light passage for reducing day time lighting load is the best technique for solar light harvesting, while this option is suitable for only walls exposed to solar light and controlling lighting is also difficult. To solve this problem light tube can be better and smarter option.
Light tubes are structure capable of collecting, transmitting and distributing daylight from atmosphere to required space.
Collection of light is done at light collector, generally light collectors are in shape of dome for better collection and able to remove dirt in case of deposition on the surface.
Light transmission is done through hollow pipe structure coated internally with highly light reflective material; light transmission is very effective in case of straight pipe, while introduction of sharp bends to be avoided and no of bends will affect transmission of light.
For light distribution, light distributors or diffuser are used and are designed in beautiful shapes to make light fitting more elegant.
Light tubes are also called as solar tube, light pipe, sun pipe etc.
Benefits of light tube :
- Day light can be harvested easily with light tube
- Quality of light is better than artificial light.
- Simple in construction.
- Attractive Light reflectors availability.
- Negligible cost of operation.
- Long life
Limitation
- Initial cost is relatively high.
- As light is directly harvested from atmosphere light intensity keeps on varying, to be supported with artificial light.
- Light filters are requiring to reduce excess light intensity
- Retrofitting in concrete roof is difficult.
- Exposed surface to sun needs to be cleaned regularly.
