This study evaluated the potential of toplighting systems in the hot and humid tropics by using Bangkok, Thailand (latitude 13.7°N) as a test location. The analysis tested both the thermal and lighting performance of three toplighting systems. Toplighting, designed for use in one-story buildings or on the top floor of taller buildings, yields a uniformly distributed light throughout a space. However, in lower latitude locations, where there is no heating period, heat gain is a critical design issue since it significantly affects the annual energy consumption of the building. Accordingly, the decision to use toplighting in these locations needs to be carefully examined before any design considerations occur. In this study, the thermal and lighting performance of three toplighting systems were compared. For the thermal performance, total cooling loads, heat gains and losses, and interior temperature were evaluated. The lighting performance parameters examined were daylight factor, illuminance level, light distribution, and uniformity. EnergyPlus was used as the thermal analysis tool, and RADIANCE, along with a physical scale model, was used as the lighting performance analysis tool. The sky conditions tested were overcast, clear sky, and intermediate sky. Results have shown that, for locations with hot and humid climates with variable sky conditions such as Bangkok, Thailand, the roof monitors perform better than the other two systems in terms of the thermal and lighting performance. With similar cooling loads, the roof monitor provides better illuminance uniformity than the skylights and lightscoops, with adequate illuminance level (at mostly higher than 500 lux).

This study evaluated the potential of toplighting systems in the hot and humid tropics by using Bangkok, Thailand (latitude 13.7°N) as a test location. The analysis tested both the thermal and lighting performance of three toplighting systems. Toplighting, designed for use in one-story buildings or on the top floor of taller buildings, yields a uniformly distributed light throughout a space. However, in lower latitude locations, where there is no heating period, heat gain is a critical design issue since it significantly affects the annual energy consumption of the building. Accordingly, the decision to use toplighting in these locations needs to be carefully examined before any design considerations occur. In this study, the thermal and lighting performance of three toplighting systems were compared. For the thermal performance, total cooling loads, heat gains and losses, and interior temperature were evaluated. The lighting performance parameters examined were daylight factor, illuminance level, light distribution, and uniformity. EnergyPlus was used as the thermal analysis tool, and RADIANCE, along with a physical scale model, was used as the lighting performance analysis tool. The sky conditions tested were overcast, clear sky, and intermediate sky. Results have shown that, for locations with hot and humid climates with variable sky conditions such as Bangkok, Thailand, the roof monitors perform better than the other two systems in terms of the thermal and lighting performance. With similar cooling loads, the roof monitor provides better illuminance uniformity than the skylights and lightscoops, with adequate illuminance level (at mostly higher than 500 lux).

This research seeks to find a design solution for reducing the energy usage in high-rise office buildings in Singapore. There are numerous methods and techniques that could be employed to achieve the purpose of designing energy efficient buildings. The Thesis explores the viability of double-skin fa??ades (DSF) to provide natural ventilation as an energy efficient solution for office buildings in hot and humid environment by using computational fluid dynamic (CFD) simulations and case study methodologies. CFD simulations were used to examine various types of DSF used in office buildings and the behaviour of airflow and thermal transfer through the DSF; the internal thermal comfort levels of each office spaces were analyzed and compared; and an optimization methodology was developed to explore the best DSF configuration to be used in high-rise office buildings in the tropics. The correlation between the fa??ade configurations, the thermal comfort parameters, and the internal office space energy consumption through the DSF is studied and presented. The research outcome of the Thesis has found that significant energy saving is possible if natural ventilation strategies could be exploited with the use of DSF. A prototype DSF configuration which will be best suited for the tropical environment in terms of its energy efficiency through cross ventilation strategy is proposed in this Thesis. A series of comprehensive and user-friendly nomograms for design optimization in selecting the most appropriate double-skin fa??ade configurations with considerations of various orientations for the use in high-rise office buildings in the tropics were also presented.

This research seeks to find a design solution for reducing the energy usage in high-rise office buildings in Singapore. There are numerous methods and techniques that could be employed to achieve the purpose of designing energy efficient buildings. The Thesis explores the viability of double-skin fa??ades (DSF) to provide natural ventilation as an energy efficient solution for office buildings in hot and humid environment by using computational fluid dynamic (CFD) simulations and case study methodologies. CFD simulations were used to examine various types of DSF used in office buildings and the behaviour of airflow and thermal transfer through the DSF; the internal thermal comfort levels of each office spaces were analyzed and compared; and an optimization methodology was developed to explore the best DSF configuration to be used in high-rise office buildings in the tropics. The correlation between the fa??ade configurations, the thermal comfort parameters, and the internal office space energy consumption through the DSF is studied and presented. The research outcome of the Thesis has found that significant energy saving is possible if natural ventilation strategies could be exploited with the use of DSF. A prototype DSF configuration which will be best suited for the tropical environment in terms of its energy efficiency through cross ventilation strategy is proposed in this Thesis. A series of comprehensive and user-friendly nomograms for design optimization in selecting the most appropriate double-skin fa??ade configurations with considerations of various orientations for the use in high-rise office buildings in the tropics were also presented.

The commercial buildings sector in the United States used 18 percent (17.93 Quads) of the U.S. primary energy in 2006. Office buildings are the largest single energy consumption category in the commercial buildings sector of the United States with annual energy consumption around 1.1 Quads. Traditional approaches used in commercial building designs are not adequate to save energy in both depth and scale. One of the most effective ways to reduce energy consumption is to improve energy performance of HVAC systems. High-performance HVAC systems and components, as well as application of renewable energy sources, were surveyed for buildings in hot and humid climates. An analysis of performance and energy saving potential estimation for selected HVAC systems in hot and humid climates was developed based on energy consumption simulation models in DOE-2.1E. A calibrated energy consumption model of an existing office building located in the hot and humid climate conditions of Texas was developed. Based on this model, the energy saving potential of the building was estimated. In addition, energy consumption simulation models were developed for a new office building, including simulation of energy saving measures that could be achieved with further improvements of HVAC system above the energy conservation codes requirements. The theoretical minimum energy consumption level for the same office building was estimated for the purpose of evaluating the whole building energy efficiency level. The theoretical minimum energy consumption model of the office building was designed to provide the same level of comfort and services to the building occupants as provided in the actual building simulation model. Finally, the energy efficiency of the building that satisfies valid energy conservation codes and the building with an improved HVAC system was estimated based on theoretically minimum energy consumption level. The analysis provided herein can be used for new building practitioners and existing building owners to evaluate energy reduction potential and the performance of innovative technologies such as dedicated outdoor air system, displacement ventilation, improved cooling system efficiency, air source heat pumps and natural gas heat pumps.