Abstract:
Energy is one of the most vital contribut ions to sustainable development
strategy of Sri Lanka. However, the r ising cost of energy generation, the
deplet ion and the unpredictability of availability of energy resources and the
adverse impacts of energy generation and its usage on the environment, have
been causing much anxiety and great concern from recent t imes. Within this
context, buildings have been considered as one of the largest consumers of
energy and have therefore been ident ified as one of the target areas for energy
conservat ion. Statistics have revealed that the proportion of energy consumed
for light ing in buildings is much greater than what is consumed ind ividually for
providing thermal comfort or other ancillary services.
Therefore adding of daylight for space, architectural designing has become a
vital overcomes above problems. Adding adequate sunlight, integration with
artificial light ing and reducing the cooling load on HVAC systems are
effect ively providing wide energy savings in buildings and houses.
The principle object ive in this research is therefore to explore strategies of
designing buildings with opt imal utilisation of natural light, efficient
application of electrical energy for inter ior light ing and minimising energy
usage of HVAC systems. A simulation modelling on daylight implementation
was carried out under this research, with different kinds of light ing arrangement
against a few different external characteristics within the control of the
designer. The computer simulation software DIALUX 4.11 version was used to
analyse illuminat ion level inside the building and a n extensive literature survey
on maximising ut ilisation of daylight and its effect on HVAC system was also
carried out under this research project.
As per the research energy savings from daylight design in buildings cannot be
realized unless the electric lights are dimmed or switched in response to the
amount of available daylight. The analysis results shows , that there is potential
for saving 51% of energy consumed for building light ing with daylight
implementation for the building. But due to practical limitation, exist ing
light ing arrangement is not suitable for daylight implementation and therefor e
new light ing arrangement was considered under this research and new light ing
arrangement shows that there is potent ial for 50% of energy saving with
daylight integration.
The analysis was further carried out for new type of luminar ies to find out
further energy saving potent ial with implementation of energy saving lights with
integration of daylight. This analysis results shows, that there is potent ial for
52% of energy saving with new type of luminaries and its arrangement. Effect
on HVAC system due to daylight implementation was also analysed and it is
shown that there is 10% increase of building cooling load due to daylight
implementation.
Also this research presents guide lines for designing of daylight efficient
buildings light ing systems to contribute towards energy conservation,
environmental protect ion and establishment of sustainable economic system as
well. This research can be further extended to analysis for different kind of
building with different wall colouring and internal objects arrangement for
opt imal energy saving with daylight implementation for commercial buildings.