Energy Efficiency and Thermal Comfort in Hospital Buildings: A Review

This paper aims to review the state of the art technologies for the energy efficiency within the hospitals sector. Hospitals are liable for an unstable amount of energy demand and joint emissions, because of their 24/7 nature of operation and hence resulting larger energy consumption than a typical commercial building. Additionally, they need high quality and warranted supplies of electricity. Due to increased energy demand and therefore the depletion of existing fossil fuel based sources, it is required to use the energy more efï¬cient. Researchers found that hospitals represent close to 6% of total energy consumption within the utility buildings sector. Heating, Ventilation and air-con (HVAC) systems are the most important a part of electricity consumption at hospitals. Apart from effective energy management system, hospitals also require energy efficiency efforts and also incorporation with renewable energy if it’s economically feasible. Apart from that, it is necessary to correlate the thermal comfort in hospitals to ensure the well-being of patients as well as optimum productivity of hospital workers. This paper reviews the energy efficiency efforts and their relation to thermal comfort in hospital buildings, to seek further research gaps for further works in this area

Heat Transfer Studies in Tube Banks with Integral Wake Splitters

This paper reports the findings from heat transfer studies with the presence of extended surfaces from tube banks which are termed as integral wake splitter plates. Employing this type of fins, investigations on heat transfer characteristics on a single circular tube as well as tube banks were carried out in cross flow of air in a rectangular duct. Experiments were carried out in the Reynolds number range 5 x 103 to 105 on a single cylinder of various splitter length-to-tube diameter ratios, L/D = 0.5, 1.0, 1.5 and 2.0. Further, tube banks consisting of 12 rows and 3 tubes per row in equilateral triangle arrangements with transverse pitch to diameter ratio, a = 2, were also investigated, the banks being made up of plain tubes or tubes with splitters. Heat transfer characteristics were studied for tubes with L/D = 0, 0.5 and 1.0 under constant heat flux conditions. Tube banks with L/D = 1.0 yielded the highest heat transfer rates. Findings from this work may be adopted to be utilized in various industrial applications such as economizer of a steam boiler, air-conditioning coils or waste heat recovery systems

Analysis of Tar Properties Produced During Co-Gasification of Empty Fruit Bunch Pellet and Oil Palm Shell

In this study, tar produced during co-gasification of empty fruit bunch pellet (EFBP) and oil palm shell (OPS) was analyzed. The aim of the analysis is to characterize tar samples with three different fuel composition of 100% EFBP:0% OPS, 75% EFBP:25% OPS and 50% EFBP:50% OPS. Two types of analysis were carried out, namely the physical and chemical analysis. Physical analysis determines the moisture content, density and calorific value of tar samples while the chemical analysis via Fourier Transform Infrared (FTIR) Spectroscopy determines the functional group in the tar samples. In general, it was found the moisture content, density and calorific value increases with higher amount of OPS in the fuel mixture. The calorific value ranges from 4.722 MJ/kg to 21. 877 MJ/kg whiles the moisture content and the density ranges from 30.90% to 47.20% and 2.74089 g/cm3 to 2.99075 g/cm3. From FTIR analysis, it was found the tar contains alcohol, carbonyl, alkene, aromatic, ether and nitro. This corresponds to the characteristic absorptions during FTIR, which were 3200cm-1 to 3600cm-1 (O-H), 1670cm-1 to 1820cm-1 (C=O), 1620cm-1 to 1680cm-1 (C=C), 1400cm-1 to1600cm-1 (C=C), 1000cm-1 to 1300cm-1 (C-O) and 1345cm-1 to 1385cm-1 (N-O)

Comparative study on energy management and efficiency category in sustainable building rating schemes

The paper aims to provide comparative study on energy management and efficiency category in sustainable building rating schemes. Eleven sustainable rating schemes have been considered in the present papers which consist of forty three tools. All the tools have been reviewed in terms of credits allocation, parameters allocation, and its credits requirement associated with energy management and efficiency category. In terms of credits allocation, all considered schemes have allocated at least ninety eight credits for parameters in energy management and efficiency category with minimum of twenty nine parameters. In addition to the credit and parameters allocation, the present work also provides specific requirement on the credits for each of the schemes. Eighty six parameters have been recognized from the tools associated to be associated with energy management and efficiency. All these parameters have been consolidated into eighteen parameters and would be very useful for the future development of the sustainable tools

Engineering Postgraduate Conference (EPC)

ABSTRACT Tungsten carbide is one of the essential materials used in carbide dies, cutting tools and components under erosion. Although Electrical Discharge Machining (EDM) is suitable for handling this material, it is not ideal for micro-hole machining due to its hardness property. The purpose of this study is to describe the characteristics of EDM micro-hole tungsten carbide using Sodick 3-axis die sinking machine with 0.5mm diameter copper as an electrode. In the current study, the effectiveness of the EDM process was evaluated in terms of material removal rate (MRR), electrode wear rate (EWR) and diameter overcut. Design of Experiment (DOE) method has been adopted and findings on the influence of the process parameters, namely peak current (I p ), pulse on time (t i ) and polarity (ve) over MRR, EWR and diameter overcut is presented in this paper. The process employs different range of peak current (1.5, 3.0(A)), pulse on time (3.2, 6.4 (μs)) and polarity ((+ve), (-ve)). Experimental results indicate that the MRR increased when the peak current with negative polarity is kept at high level whilst the EWR minimised when the negative polarity with low level of peak current setting is employed. In the case of diameter overcut, it has been found that the use of positive polarity associated with low level pulse on time setting will minimise the diameter overcut and produce a constant micro-hole shape

Development and Performance Investigation of a Unique Dual-rotor Savonius-type Counter-rotating Wind Turbine

Wind power is sustainable and prevalent virtually all over the globe. However, the conversion efficiency of the conventional single-rotor wind turbine (SRWT) is still far from satisfactory. The dual-rotor counter-rotating concept is among the reliable techniques used to enhance the efficiency of a wind energy conversion device for its renowned effectiveness. This study aims to investigate the performance of a Savonius dual/twin-rotor system, particularly in low-speed wind conditions while employing the counter-rotating technique. The evaluation of this technique is presented in terms of aerodynamic characteristics, including the power and torque coefficients. The results have shown that the new concept was able to improve the performance of the system extensively and was capable of operating in a lower wind speed condition. Compared to a single-rotor system, an additional 42% more torque was possible owing to the existence of a second rotor in the new system. The results have also revealed that the conversion efficiency of the system has been enhanced substantially. A corresponding average power coefficient of up to 28% was achieved. The present technique is thought to be promising for wind energy conversion systems, including sites with poor wind conditions

Heat transfer in a bank of tubes with integral wake splitters

Paper presented at the 5th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, South Africa, 1-4 July, 2007.The paper deals with the investigations on heat transfer characteristics of a circular tube as well as tube banks with integral downstream splitter plates in cross flow of air in a rectangular duct. The experiments were carried out in the Reynolds number range 5 x 103 to 105 on single plain cylinder and single cylinder of various splitter length-to-tube diameter ratios, L/D = 0.5, 1.0, 1.5 and 2.0. Further, tube banks consisting of 12 rows and 3 tubes per row in equilateral triangle arrangement with transverse pitch to diameter ratio, a = 2, were also investigated, the banks being made up of plain tubes or tubes with splitters. Heat transfer characteristics were studied for tubes with L/D = 0, 0.5 and 1.0 under constant heat flux conditions. Tube banks with L/D = 1.0 yielded the highest heat transfer rates. They were also superior to single tubes with L/D = 1.0.cs201

Design and Development of Downdraft Gasifier to Generate Producer Gas

The drive towards renewable energy become intense nowadays due to the increasing price of fossil fuels and depletion of their sources. Among promising resource of renewable energy is the biomass. In Malaysia, oil palm biomass are available in large quantity and suitable for conversion into value added bio-fuels. In this study, an-innovative small-scale downdraft gasifier was designed, development and tested for biomass gasification. The gasifier operates at flowrate less than 0.1 m/s3 with a capacity of 5 KW. During testing and commissioning of the gasifier, the maximum efficiency of the gasifier was found to be about 71% when firing empty fruit bunch pellets. This gasifier has potentials to be up scaled for actual use either for domestic or industrial use.Â

Potential of utilizing solar chimney as an energy efficiency measure in Malaysian hospitals

Many energy efficiency measures were proposed to reduce the high energy demand in hospitals. Solar chimney is a form of passive solar heating and cooling system that can be used for temperature regulation and ventilation of a building This paper explores the solar chimney’s performance in terms of air changes per hour (ACH) in Malaysian tropical climate were thus, investigated for its feasibility in Malaysian hospitals. A 2D CFX model is simulated at four different times (8 am, 10 am, 2pm and 4 pm). Openings provided at the bottom and top of the chimney and at the right of the cabin with dimension of 1 m located 1 m from the floor level to allow air with room temperature to enter the cabin and towards the solar chimney. Simulations were validated form previous study and the study use solar irradiance from previous study to simulate Malaysia’s solar irradiance and outside temperature. Steady state and laminar flow were used in this study to model air turbulence in the cabin to the solar chimney. The results show that the simulations have been validated and all 4 of different time have been simulated. 2 pm with the highest solar irradiance have the most air changes per hour (ACH), while 8 am with the lowest solar irradiance have the least ACH. Further experimental study is currently ongoing

Experimental and numerical investigations of Underground Coal Gasification (UCG) using half-teardrop shape cavity

In this work, the process of Underground Coal Gasification (UCG) was studied experimentally and numerically. The typical cavity of UCG was a half-teardrop shape. Thecoal samples were collected from Mae Moh coal mine, Thailand. The coal type is mainly lignite. To generate the gasification process, the coal sample was heated in the half-teardrop cavity by injecting partial oxidant, which is air, according to the Equivalent Ratio (ER) of 0.1, 0.2, 0.3, 0.5, and 0.7. The properties of the product gas were measured using a syngas analyser. CFD technique, ANSYS (Fluent), was used to simulate flow characteristics and gasification process in the cavity. The experimental results show that the low heating value (LHV) of syngas peaks at 0.92 MJ/m3 when ER = 0.1, and LHV decreases monotonically as ER increases. The CFD results show that the area of high temperature in the UCG cavity is larger when the ER was great