Daylighting System for Visual and Thermal Comfort

Daylight is cheap, abundant, sustainable and available everywhere, furthermore, it is free. How best we harness this resource and make judicious use of it is up to us. The aspect of harnessing daylight is one that looks into the utilisation of daylight to see how we can best make use of this invaluable resource. However, the difficulty of using daylight is that of its unreliability and its unavailability after sunset. This paper aims to look at harnessing daylight to be used in buildings to light the building naturally while at the same time maximising its use as a heat source in the temperate climate, and to deter its high penetrable properties so as to curb its over-heating properties in the tropics. The paper further presents results to previous and on-going experiments conducted to investigate the potential of using the solar energy for supply of thermal comfort into the residential buildings, as well as lighting the interior.The system made use of driving light rods through a well insulated box of with real size proportions of internal dimensions thus: width 2.5m x height 2.5m and depth 3.0m, floor area of 7.5m2. This was done under 3 conditions: 1) the use of a double glazed fixed window of size 1.0m x 1.0m, 2) 13 light rods, 3) 25 light rods in the same insulated box under the same conditions. Results of all the tests, help to show the distribution of the light as well as its intensity on the adjacent wall. The results also show the temperatures recorded and which system best suits either the tropical (hot) climate or the temperate climate in a bid to improve thermal comfort. The efficiency of all the systems was investigated, as an applicability in residential buildings.