Transport of light using tubular light guide

Within the framework of sustainable development, we are trying to use the most of the land and already existing spaces for human needs - whether for housing, jobs, health care and education for example. These spaces have different demands on visual activity and thus the amount of daylight. Sometimes we are already not able to provide enough daylight by window to create an ideal visual conditions. One of the few possibilities for transport daylighting can be tubular light guide tube, which is able to transmit light over long distances. Its design is very complicated, since producers are only given reflectance material tube of light guide, but can not guarantee the necessary amount of light at a given distance or number of curves of light guide. The problem may be in terms of heating technology, where manufacturers have certified only individual elements of the light guide, but not the whole light guide.