DAYLIGHTING in ENERGY EFFICIENCY A case of office building in Kathmandu
Date
2022-09
Authors
Journal Title
Journal ISSN
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Publisher
IOE Pulchowk Campus
Abstract
Architecturally, light and design is a collective term where light illuminates the form,
space, texture, color and vibe of the space. It is the only medium to perceive object,
which can be in the form of both daylighting and artificial lighting. Office buildings are
operated for 7 – 8 hours daily on weekdays where light is most to carry out any type of
work. Several researchers have found daylighting is beneficial to human
psychologically and in reducing the active energy consumed by the building for
illumination. The office buildings of Kathmandu are turned spaces and rarely designed
while the designed ones are with deep floor plates or with glass curtain wall which
results in visually uncomfortable indoor environment. The research aimed to investigate
the passive strategies for illuminating space maintaining visual comfort and at the same
time reducing the use of active energy. Using the climate data from DHM, an office
building floor was simulated in Velux Daylight Visualizer 3, with varying window wall
ratio (WWR) ranging from 10% – 100% and Autodesk Ecotect software, 2011 to
analyze daylighting level and energy consumption respectively w.r.t. to WWR to
deduce the best WWR required to meet the required optimum illumination in the office
building while reducing energy consumption which is a quantitative analysis. The result
showed that 30% window wall ratio is optimum for the office building of Kathmandu
which holds clerical work as a prime task. The lighting energy is reduced by 66.92%,
cooling energy is reduced by 10% and the total energy consumption of the floor is
reduced by 5 % with changed WWR and window configuration. The research concludes
that the daylighting findings will be helpful to designers in the early design phase,
academic researchers and also to prepare guidelines, policy maker to create visually
and functionally friendly space.
Description
Human being spend large quantity of their time indoor, indulging in different activities
to keep their life moving. With the development of technology, use of electronic device
is high both for business and recreational purpose. The age of 15 to 64 is defined to be
working age population (OECD, 2021). 59.8% of world population was found to be in
professional workforce in 2020 (DPE, 2021). The working population of Nepal in 2021
is estimated to be 60.9% (ILO, 2021). Office worker form a considerable amount of
population. Daylight is considered as an important element for determining the quality
of space as it plays a major role in resource conservation as well as in occupant’s level
of productivity, health and comfort (Hafiz, 2015). People prefer working near windows
as it stimulates the mind, reduces stress and increases productivity (Khandelwal, n.d.).
The amount of sunlight hitting and penetrating the building depends upon the building
design and its boundary condition
Keywords
Daylighting, artificial lighting, visual comfort, energy, simulation