A study on energy performance of hotel buildings in Singapore

This paper presents a study on energy performance of Singapore's hotel buildings. Energy consumption data and other pertinent information were collected from 29 quality hotels through a national survey. Building features and operational characteristics contributing to the variations in hotel energy performance were discussed. The annual average total energy use intensity (EUI) in these hotels is 427 kWh/m2. Electricity and gas are used in all sampled hotels, and some hotels also use diesel to power standby generator or hot water boiler. We also investigated relationships between electricity consumption and number of occupied rooms in individual hotels; the weak correlations found indicate it is necessary to improve energy management when occupancy rate is low. Besides, Pearson correlations between hotel energy use intensity and possible explanatory indicators revealed that three-star hotels differ from high class establishments in energy use. Worker density and years after the last major energy retrofit were also found to be highly correlated to hotel building energy use intensity. Also discussed in this paper is the effect of weather conditions on electricity consumption of the hotels.

Context dependency of comfort and energy performance in mixed mode offices

This article investigates the context dependency of comfort and energy performance in mixed-mode offices in the climate of Athens, Greece. It is based on a parametric study using the simulation software EnergyPlus. Context refers to different building design priorities on the real estate market (prestige, low cost and green), occupant behaviour scenarios (ideal and worst case) and cooling strategies (fixed and adaptive set points). Results are evaluated according to energy consumption and related greenhouse gas emissions, daylight autonomy, view and percentage of working time when heating and cooling are operating. The results indicate that a holistic approach to comfort and energy performance evaluation focused on the specific context of a building and its occupants is necessary to develop appropriate optimization strategies. In early design stages, such specific information is not yet available and ideal/worst-case scenarios can indicate the magnitude of influence of occupants compared to building design.

Climate change sensitivity of comfort and energy performance criteria for offices

The climate change scenarios of the Intergovernmental Panel on Climate Change (IPCC) predict a significant increase in temperatures over the next decades. Architecture and building occupants have to respond to this change, but little information is currently available in how far the predicted changes are likely to affect comfort and energy performance in buildings. This study therefore investigates the climate change sensitivity of the following parameters: adaptive thermal comfort according to Ashrae Standard 55 and EN 15251, energy consumption, heating and cooling loads, and length of heating and cooling periods. The study is based on parametric simulations of typical office room configurations in the context of Athens, Greece. They refer to different building design priorities and account for different occupant behaviour by using an ideal and worst case scenario. To evaluate the impact of the climate change, simulations are compared based on a common standard weather data set for Athens, and a generated climate change data set for the IPCC A2 scenario. The results show a significant impact of the climate change on all investigated parameters. They also indicate that in this context the optimisation of comfort and energy performance is likely to be related to finding the best possible balance between building (design) and occupant behaviour and other contextual influences, rather than a straightforward optimisation of separated single parameters.

Optimising the life cycle energy performance of residential buildings

A holistic approach to low-energy building design is essential to ensure that any efficiency improvement strategies provide a net energy benefit over the life of the building. Previous work by the authors has established a model for informing low-energy building design based on a comparison of the life cycle energy demand associated with a broad range of building assemblies. This model ranks assemblies based on their combined initial and recurrent embodied energy and operational energy demand. The current study applies this model to an actual residential building in order to demonstrate the application of the model for optimising a building’s life cycle energy performance. The aim of this study was to demonstrate how the availability of comparable energy performance information at the building design stage can be used to better optimise a building’s energy performance. The life cycle energy demand of the case study building, located in the temperate climate of Melbourne, Australia, was quantified using a comprehensive embodied energy assessment technique and TRNSYS thermal energy simulation software. The building was then modelled with variations to its external assemblies in an attempt to optimise its life cycle energy performance. The alternative assemblies chosen were those shown through the author’s previous modelling to result in the lowest life cycle energy demand for each building element. The best performing assemblies for each of the main external building elements were then combined into a best-case scenario to quantify the potential life cycle energy savings possible compared to the original building. The study showed that significant life cycle energy savings are possible through the modelling of individual building elements for the case study building. While these findings relate to a very specific case, this study demonstrates the application of a model for optimising building life cycle energy performance that may be applied more broadly during early-stage building design to optimise life cycle energy performance.

Impact of climate change on thermal comfort and energy performance in offices - a parametric study

This paper investigates the impact of climate change on comfort and energy performance in offices in relation to the influence of building design and occupants. It focuses on a typical cellular office room in the context of Athens, Greece, as input for a parametric study using the building simulation software EnergyPlus. Three different building design variations are combined with two different occupant scenarios and 4 different weather data sets for IPCC climate change scenario A2.

For naturally ventilated buildings adaptive thermal comfort is evaluated according to ASHRAE Standard 55 and EN 15251. For mixed mode context evaluation is focused on greenhouse gas emissions and peak heating / cooling loads. Results indicate significant impact of the climate change on thermal comfort, and deviations between both comfort models. Comparing climate change, building design and occupant scenarios indicates that building design is the predominant influence on thermal comfort, whereas occupants are the predominant influence on greenhouse gas emissions.

Key influences on office comfort and energy performance in different climates

This paper investigates the magnitude of influence of climate, architectural design and occupants on thermal comfort and final energy consumption in offices in different climates. A parametric study for a typical cellular office room has been conducted using the simulation software EnergyPlus. Two different occupant scenarios are each compared with three different architectural design variations and modelled in the context of three different locations for the IPCC climate change scenario A2 for 2030. The parameters evaluated in this study are final energy consumption and adaptive thermal comfort according to ASHRAE Standard 55. The study shows that the impact of occupants on final energy performance is larger than the impact of architectural design in all investigated climates, but the impact of architectural design is predominant concerning thermal comfort. Warmer climates show larger optimisation potential for comfort and energy performance in offices compared to colder climates.

Energy performance of medium-sized healthcare buildings in Victoria, Australia- a case study

This paper investigates the energy performance of three medium-sized healthcare buildings in Victoria, Australia, that operate only during the daytime. The aim is to provide preliminary understanding of energy consumption in this particular typology in Australia in relation to the available benchmarks. This paper also identifies the differences of energy consumption between different functional areas within medium health facilities. Building features and operational characteristics contributing to the variations in healthcare energy performance are discussed. The total annual energy consumption data ranging from 167-306 kWh/m(2) or 42-72 kWh/m(3) were compared against international data from various climatic zones. Some of the drivers of energy consumption were determined and potentials for energy and water conservation were identified. Comparison with international standards shows a possibility to achieve lower energy consumption in Victorian healthcare buildings.

A classification of healthcare facilities: toward the development of energy performance benchmarks for day surgery centers in Australia

OBJECTIVE: In the literature, there is no consistent classification of healthcare facilities. In order to benchmark, assess, and compare the environmental performance of these buildings, it is important to clearly identify the typology within the scope of a particular research. This article identifies the different typologies within the healthcare sector, particularly in Australia, with the aim of the development of energy performance benchmarks for day surgery/procedure centers. BACKGROUND: Healthcare buildings encompass a wide range of facilities. They all share the same purpose of healing and offering a health service for patients. However, they vary significantly in terms of patient type and service provided. These buildings consume a considerable amount of energy, and as a result of the different designs and sizes, their pattern of energy consumption varies. METHODS: The research used a systematic review of the literature to determine how the term "healthcare facility" has been employed in different contexts. In order to better understand the differences in healthcare facilities, definitions and the origin of hospitals and healthcare facilities are introduced and a framework for the classification of healthcare facilities and hospitals is proposed. RESULTS: Healthcare facilities are classified into the following six categories: patient type, care provided, management and ownership, level of care, facility size, and location. Based on these classifications, a categorization for the studies of energy performance in healthcare is introduced. CONCLUSIONS: This study provides a basis for assessment and comparison for a particular healthcare building typology that will assist researchers working in the field of design and energy assessment of healthcare facilities.