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This paper aims to present an analytical investigation of energy and exergy performance on a solar flat plate collector (SFPC) with Cu-CuO/water hybrid nanofluid, Cu/water and CuO/water nanofluids as collector running fluids.

Heat transfer characteristics, pressure drop and energy and exergy efficiencies of SFPC working on these nanofluids are investigated and compared. In this study, a comparison is made by varying the mass flow rates and nanoparticle volume concentration. Thermophysical properties of hybrid nanofluids are estimated using distinctive correlations available in the open literature. Then, the influence of these properties on energy and exergy efficiencies of SFPC is discussed in detail.

Energy analysis reveals that by introducing the hybrid nanoparticles in water, the thermal conductivity of the working fluid is enhanced by 17.52 per cent and that of the individual constituents is enhanced by 15.72 and 15.35 per cent for Cu/water and CuO/water nanofluids, respectively. This resulted in 2.16 per cent improvement in useful heat gain for hybrid nanofluid and 1.03 and 0.91 per cent improvement in heat gain for Cu/water and CuO/water nanofluids, respectively. In line with the above, the collector efficiency increased by 2.175 per cent for the hybrid nanofluid and 0.93 and 1.05 per cent enhancement for Cu/water and CuO/water nanofluids, respectively. Exergy analysis elucidates that by using the hybrid nanofluid, exergy efficiency is increased by 2.59 per cent, whereas it is 2.32 and 2.18 per cent enhancement for Cu/water and CuO/water nanofluids, respectively. Entropy generation is reduced by 3.31, 2.35 and 2.96 per cent for Cu-CuO/water, Cu/water and CuO/water nanofluids, respectively, as compared to water.

However, this is associated with a penalty of increment in pressure drop of 2.92, 3.09 and 2.74 per cent for Cu-CuO/water, Cu/water and CuO/water nanofluids, respectively, compared with water.

It is clear from the analysis that Cu-CuO/water hybrid nanofluids possess notable increment in both energy and exergy efficiencies to use them in SFPCs.

The purpose of this paper is to identify the impact of traditionally unmonitored energy sources and sinks on assessment of the as-built thermal performance of occupied homes. The analysis aims to demonstrate the potential scale of uncertainties introduced in a heat balance estimation of the heat transfer coefficient (HTC) when using in-use monitored data.

Energy flows for two UK homes – one a 1930s dwelling with high heat loss, the second a higher-performing 2014-built home – are predicted using the UK Government’s standard assessment procedure (SAP) and visualised using Sankey diagrams. Selected modelled energy flows are used as inputs in a quasi-steady state heat balance to calculate in-use HTCs as if from measured data sets gathered in occupied homes. The estimated in-use HTCs are compared against SAP-calculated values to illustrate the impact of including or omitting various heat sources and sinks.

The results demonstrate that for dwellings with low heat loss, the increased proportion of heating demand met by unmetered internal and solar gains informs a greater sensitivity of a heat balance estimation of the HTC to their omission. While simple quasi-steady state heat balance methods may be appropriate for dwellings with very high heat loss, alternative approaches are likely to be required for those with lower heat loss.

A need to understand the impacts of unmetered heat flows on the accuracy with which a building’s thermal performance may be inferred from in-use monitored data is identified: this paper illustrates the scale of these impacts for two homes at opposite ends of the energy performance scale.

This paper aims to optimise building orientation in Tehran, as well as determining the impact of its shape, relative compactness (RC) and glazing percentage on its optimised orientation.

A cubic module was used and a set of 8 of the same module with 16 different formations were analysed for their orientation (360°), the RC (four groups) and the amount of glazing percentage (25, 50 and 75 per cent).

The results show that the optimised orientation of a building in Tehran strongly depends on its passive solar heat gain elements, their orientation and their position in building; furthermore, glazing percentage amount, amongst the studied factors, plays the most important role in determining a building’s orientation.

The application of the findings of this study in Tehran city planning and also technical details of buildings will lead to a great energy saving in construction sector. Furthermore, the deployment of the proposed design guidelines in construction has explicitly been proven to save a prodigious amount of energy.

The main research question is taken directly from authors’ initiative when working as university professor and research associate. The case study buildings, their morphological configurations and sustainable features have not been presented before in an academic journal.

WHAT a wonderful lady is Dr. Lillian Gilbreth. Whatever her age it can be discounted since years have little or no effect on one so youthful in spirit.

The Middle East and North Africa (MENA) region is known for its extreme weather conditions during Summer. A major determinant of the sustainability of the design of a building is its fenestrations. The purpose of this paper is to explore the problem of designing and locating windows on building facades such that a number of relevant criteria to the MENA region are optimised, including solar heat gain, privacy, daylighting and cost of installation.

A multi-objective optimisation problem is proposed with the focus on capturing the requirements of residential dwellings in the MENA region. Since the problem contains conflicting objectives that need to be optimised, a lexicographic approach is adopted. In order to display the Pareto curve, a bi-objective analysis based on the ε-constraint method is utilised.

The conflicting nature of the proposed problem is indicated via the Pareto optimal solutions yielded. Depending on the preference of criteria adopted in lexicographic optimisation, the location of the windows on the building façade tends to change. The bi-objective analysis indicates the importance of balancing out the daylight factor against each of privacy, solar heat gain and installation cost criteria. Furthermore, an analysis conducted in three major cities in the MENA region highlights the discrepancy in design alternatives generated depending on the local climatic condition.

This work proposes a novel mathematical optimisation model which focuses on producing a sustainable design and layout for windows on the facades of residential dwellings located in the MENA region. The proposed model provides designers with guidance through an automated support tool that yields optimised window designs and layout to ensure the sustainability of their designed buildings.

Implementation of the concept of passive solar heating design in dwellings has the potential to reduce energy consumption and reduce carbon emissions at little or no cost to the developer but with real benefit to the occupier. The aim of this paper is to investigate the possible benefits to be gained by the application of passive solar heating concepts to the orientation and fenestration of domestic buildings.

The approach used has been to select a simple domestic building designed to current building regulations and apply to it modifications which embody the principles of passive solar heating design. The anticipated performance of the modified building has then been compared with that of its counterpart of conventional configuration by application of a number of currently available simulation models. This study forms part of the Department of Trade and Industry sponsored Knowledge Transfer Partnership between Coventry University and Kenneth Holmes Associates, Chartered Architects.

It is predicted that by careful selection of orientation of a domestic building and modification of its layout, in order that glazing is strategically located, it is possible to effect significant improvements in energy consumption. There is some variation in the output of the alternative techniques but they present a common overall result.

The solutions are purely predictive and it would be of great value if the outcomes could be evaluated by medium term measurement of the performance of dwellings constructed to the proposed design principles.

The concept under analysis could, at little or no cost, result in reduced energy demand in domestic buildings. In the current environmental climate, even modest improvements should be of considerable interest to designers and developers.

Draws upon alternative approaches to passive solar heating design in dwellings and reaches conclusions based on the application of these different approaches to a real live case study.

This study investigates the impact and economic viability of energy-efficient building envelope and orientation for contributing net zero energy building (NZEB) and suggests optimum thermal insulation thickness, optimum wall thickness, appropriate orientation and glazing types of window in the contexts of unique Bangladeshi subtropical monsoon climate.

The whole study was conducted through energy simulation perspective of an existing office building using building information modeling (BIM) and building energy modeling (BEM) tools which are Autodesk Revit 2017, Autodesk Green Building Studio (GBS) and eQUEST. Numerous simulation patterns were created for energy simulation considering building envelope parameters and orientations. A comprehensive data analysis of simulation results was conducted to sort out efficient passive design strategies.

The optimum thermal mass and thermal insulation thickness are 6.5 and 0.5 inches, respectively, considering energy performance and economic viability. This study highly recommends that a building should be designed with a small window-to-wall ratio in the south and west face. The window should be constructed with double glazing Low-E materials to reduce solar heat gain. The studied building saves 9.14% annual energy consumption by incorporating the suggested passive design strategies of this study.

The output of this work can add some new energy-efficient design strategies to Bangladesh National Building Code (BNBC) because BNBC has not suggested any codes or regulations regarding energy-efficient passive design strategies. It will also be useful to designers of Bangladesh and other countries with similar subtropical climatic contexts which are located in Southeast Asia and Northern Hemisphere of Earth.

This paper aims to present the numerical models and experimental outcomes pertain to the performance of the parabolic dish concentrator system with a modified cavity-type receiver (hemispherical-shaped).

The numerical models were evolved based on two types of boundary conditions; isothermal receiver surface and non-isothermal receiver surface. For validation of the numerical models with experimental results, three statistical terms were used: mean of absolute deviation, R² and root mean square error.

The thermal efficiency of the receiver values obtained using the numerical model with a non-isothermal receiver surface found agreeing well with experimental results. The numerical model with non-isothermal surface boundary condition exhibited more accurate results as compared to that with isothermal surface boundary condition. The receiver heat loss analysis based on the experimental outcomes is also carried out to estimate the contributions of various modes of heat transfer. The losses by radiation, convection and conduction contribute about 27.47%, 70.89% and 1.83%, in the total receiver loss, respectively.

An empirical correlation based on experimental data is also presented to anticipate the effect of studied parameters on the receiver collection efficiency. The anticipations may help to adopt the technology for practical use.

The developed models would help to design and anticipating the performance of the dish concentrator system with a modified cavity receiver that may be used for applications e.g. power generation, water heating, air-conditioning, solar cooking, solar drying, energy storage, etc.

The originality of this manuscript comprising presenting a differential-mathematical analysis/modeling of hemispherical shaped modified cavity receiver with non-uniform surface temperature boundary condition. It can estimate the variation of temperature of heat transfer fluid (water) along with the receiver height, by taking into account the receiver cavity losses by means of radiation and convection modes. The model also considers the radiative heat exchange among the internal ring-surface elements of the cavity.

Transparent insulation materials (TIMs) have been developed for application to building facades to reduce heating energy demands of a building. The purpose of this research is to investigate the feasibility of TI‐applications for high‐rise and low‐rise office buildings in London, UK, to reduce heating energy demands in winter and reduce overheating problems in summer.

The energy performance of these office building models was simulated using an energy simulation package, Environmental Systems Performance‐research (ESP‐r), for a full calendar year. The simulations were initially performed for the buildings with conventional wall elements, prior to those with TI‐systems (TI‐walls and TI‐glazing) used to replace the conventional wall elements. Surface temperatures of the conventional wall elements and TI‐systems, air temperature inside the 20 mm wide air gaps in the TI‐wall, dry‐bulb zone temperature and energy demands required for the office zones were predicted.

Peak temperatures of between 50 and 70°C were predicted for the internal surface of the TI‐systems, which clearly demonstrated the large effect of absorption of solar energy flux by the brick wall mass with an absorptivity of 90 percent behind the TIM layer. In the office zones, the magnitude of temperature swings during daytime was reduced, as demonstrated by a 10 to 12 h delay in heat transmission from the external façade to the office zones. Such reduction indicates the overheating problems could be reduced potentially by TI‐applications.

This research presents the scale and scope of design optimisation of TI‐systems with ESP‐r simulations, which is a critical process prior to applications to real buildings.

This paper describes an introduction to a simple modelling tool for designers of environmentally sensitive buildings.

The theoretical basis of the program is explained with examples given of typical program output.

The package can be used as an environmental simulator of a building's energy consumption and energy‐related carbon dioxide emissions. It is specifically designed to help meet the more stringent requirements of the Building Regulations for Fuel and Power L2 Approved Document, April 2002.

The designer can explore building size, shape, fenestration, orientation and fabric thermal properties to minimise a buildings' environmental effect. Aspects of heating, lighting, and natural and mechanical ventilation with heat recovery systems can also be investigated. The spreadsheet is best used to check that buildings will comply with the regulations or used as an early design aid rather than a detailed design simulator of building performance. The program should therefore be of particular interest to architects, building surveyors and building control officers rather than building service engineers.

Describes an innovative approach to thermal design.