Abstract:
This research study is focused on the applications to find out the potential cost effective
energy saving measures (ESMs) to make projection of EUI (Energy Unit Intensity)
values in kWh/m2.year for high rise office buildings in Colombo, Sri Lanka, as it is a
widely accepted fact that energy efficient building design measures and techniques are
application specific.
Therefore, the objectives of this thesis include detailed study in relation to office building
energy efficient measures (EEMs) and also study for office building energy saving
potential using established Baseline Building parameters. This helps to quantify ‘office
buildings energy saving potential’ and make projection of building energy consumption
savings for new office buildings. This also helps to find out the potential energy saving
measures to make projection of EUI values for office buildings in Colombo, Sri Lanka.
The results of this research are based on two selected office building applications in
Colombo. The building categories subject to this research are one high-rise office
building (height around 100m) and one medium-rise office building (height around 30m)
in Colombo. Life cycle analysis is done using the present tariff structure of the Ceylon
Electricity Board.
In most of the projects, the building sites are selected before the involvement of the
design team. Also, within the limited site area, the building is orientated and the outer
appearance of the building also finalized in order to maximize the useable capacity and
aesthetics. Therefore, due to the above project constraints, some ESMs for building form
such as aspect ratio of the building, orientation (reduced East-West faced windows) and
WWR (window to wall ratios) are not considered in investigation.
The analyzing of the potential ESMs for the selected office buildings are limited to the
following energy saving measures due to the project specific limitation mentioned above,
current industry practices, modeling software analysis limitations, owners of the
buildings planning to rent out the spaces to outside tenants, time frame limitation of this
study, viz., Selective glazing for windows, Perimeter circulation space, Open office space
at perimeter, Daylighting through windows, Energy efficient lamps and ballasts, Lighting
controls and High Efficiency cooling equipment (i.e. efficient chillers).
TRACE 700 computer simulation software is used for modeling the buildings as it is a
detailed simulation tool that computes building energy use based on the interactions
between climate, building form and fabric, internal gains, HVAC systems and day
lighting integration.
It has been found that incorporation of cost effective energy saving measures (ESMs) for
high-rise office buildings in Colombo, Sri Lanka have greater potential to reduce annual
electrical energy consumption by minimum 20 percent in comparison with a Baseline
Building and it can also establish better EUI values for high-rise office buildings in
Colombo, Sri Lanka.
Based on this study, it has been established that the EUI value for the high-rise office
building in Colombo is 124 kWh/m2.year and EUI value for the medium-rise office
building in Colombo is 83 kWh/m2.year.
Further it has been found that the payback periods for selected cost effective ESMs are
between 2.3 and 3.8 years under Ceylon Electricity Board (CEB) present tariff structure
(General Purpose tariff).
It is recommended that further research be carried out in this area for both computer
modeling and data collection from existing office buildings in Sri Lanka to establish a
better and more precise EUI values and higher annual energy saving percentage for office
buildings in Sri Lanka, as this study is limited to few ESMs and computer simulation has
been done for only two office building applications.