The Experts below are selected from a list of 285 Experts worldwide ranked by ideXlab platform
Moncef Krarti - One of the best experts on this subject based on the ideXlab platform.
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impact of switchable Roof Insulation on energy performance of us residential buildings
Building and Environment, 2020Co-Authors: Ammar H A Dehwah, Moncef KrartiAbstract:Abstract In the analysis described in this paper, the energy efficiency benefits of switchable Insulation systems (SIS) are evaluated when applied to Roofs for US residential buildings. Unlike conventional static Insulations, SISs can change their thermal properties based on control strategies to achieve desired objectives. In this analysis, SISs applied to Roofs are controlled to minimize heating and cooling thermal loads for US housing units. Specifically, 2-step controls are utilized to switch the R-value of SISs between low and high levels depending on outdoor and indoor thermal interactions in order to reduce heating and cooling needs while maintaining thermal comfort within a prototypical one-story home located in different US climates. The analysis results indicate that SISs can significantly reduce energy consumption for heating and cooling systems. The energy efficiency effectiveness of SISs is found to increase for high reflective Roofs and for high difference between the high and low R-values especially to reduce cooling energy needs for mild and heating dominated climates. In particular, the deployment of 2-step control strategies operating SISs can reduce annual energy use by up to 44% for space cooling and up to 17% for space heating.
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Analysis of high-energy performance residences in Nigeria
Energy Efficiency, 2019Co-Authors: Byung Chang Kwag, Babayo Mohammed Adamu, Moncef KrartiAbstract:Households account for over 80% of the total energy consumed in Nigeria. This paper evaluates optimal and cost-effective energy efficiency measures for residential buildings in Nigeria. Specifically, several energy-efficient design measures are considered in the optimization analysis including window types and sizes, wall and Roof Insulation levels, lighting power densities, cooling set point temperature, and high energy-efficient cooling systems. A sequential search optimization technique is utilized to determine the best energy efficiency measures that minimize life-cycle costs while maximizing source energy savings. Optimized energy-efficient measures for a typical residential building are identified for three cities to account for a wide range of climatic conditions within Nigeria. The optimization results indicate that utilizing energy-efficient lighting fixtures and high efficient air-conditioning system was required to design high-energy performance residential buildings throughout the tropical climatic zones in Nigeria. Combined with optimal energy efficiency measures and PV systems, residential buildings can be designed to be net-zero or net-positive energy assisting Nigerian households to have access to electricity especially in the rural areas.
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Design Optimization of Energy Efficient Office Buildings in Tunisia
Journal of Solar Energy Engineering-transactions of The Asme, 2013Co-Authors: Moncef KrartiAbstract:Optimal and cost-effective energy efficiency design and operation options are evaluated for office buildings in Tunisia. In the analysis, several design and operation features are considered including orientation, window location and size, high performance glazing types, wall and Roof Insulation levels, energy efficient lighting systems, daylighting controls, temperature settings, and energy efficient heating and cooling systems. First, the results of the optimization results from a sequential search technique are compared against those obtained by a more time consuming brute-force optimization approach. Then, the optimal design features for a prototypical office building are determined for selected locations in Tunisia. The optimization results indicate that utilizing daylighting controls, energy efficient lighting fixtures, and low-e double glazing, and Roof Insulation are required energy efficiency measures to design high energy performance office buildings throughout climatic zones in Tunisia. In particular, it is found that implementing these measures can cost-effectively reduce the annual energy use by 50% compared to the current design practices of office buildings in Tunisia.
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Design optimization of energy efficient residential buildings in Tunisia
Building and Environment, 2012Co-Authors: Moncef KrartiAbstract:Abstract A sequential search technique is applied to optimize the design of residential buildings in Tunisia in order to minimize their life cycle energy costs while increasing their energy efficiency. In the analysis, design features of air-conditioned single-family homes (i.e., villas) are considered including orientation, window location and size, glazing type, wall and Roof Insulation levels, lighting fixtures, appliances, and efficiencies of heating and cooling systems. First, the results of the sequential search technique are compared against those obtained by a more time consuming brute-force optimization approach. Then, the optimal design features for villas are determined for selected locations in Tunisia. The optimization results indicate that adding Roof Insulation, reducing air infiltration, installation energy efficient appliances, lighting fixtures, and heating and cooling equipment are required energy efficiency measures to design high energy performance homes throughout climatic zones in Tunisia. In particular, it is found that implementing these measures can cost-effectively reduce the annual energy use by 50% compared to the current design practices of homes in Tunisia.
Dennis Postlethwaite - One of the best experts on this subject based on the ideXlab platform.
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A comparative Life Cycle assessment of building Insulation products made of stone wool, paper wool and flax
The International Journal of Life Cycle Assessment, 2004Co-Authors: Anders C. Schmidt, Allan A. Jensen, Anders U. Clausen, Ole Kamstrup, Dennis PostlethwaiteAbstract:Insulation of buildings in order to save heating energy is an important technology for enabling sustainable development. This paper summarises the results of a comparative LCA study according to ISO 14040 standard series of HT stone wool, flax representing crop grown products and paper wool representing recycled products applied for Roof Insulation. As the three materials have vastly different lifecycles, yet fulfil the same function cycles, the methodology used should be of general interest. Part 1 consists of the project background, goal and scope definition, a detailed life cycle inventory analysis with sensitivity analysis, impact assessment and interpretation. The actual comparison of the results from the life cycle assessments of the three products, in which an attempt is made to answer the question of whether the biological products flax and paper wool are more environmentally preferable than the mineral product stone wool representing more traditional Insulation materials, is discussed in Part 2.
Constantinos Kittas - One of the best experts on this subject based on the ideXlab platform.
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Influence d'un brise-vent sur les pertes convectives et radiatives d'une serre
Boundary-Layer Meteorology, 1992Co-Authors: Constantinos KittasAbstract:An experimental study of air flow near the walls of a greenhouse protected by a natural windbreak shows that a low speed reversed flow is produced between the two obstacles and relatively large wind speeds and gradients are located at the top of the greenhouse (Figure 1). Estimation of the convective heat fluxes from the different zones of the greenhouse cover to the surroundings shows that heat losses by convective processes are most important from the top of the greenhouse. This implies a need for good greenhouse Roof Insulation in order to save energy.
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Influence d'un brise-vent sur les pertes convectives et radiatives d'une serre
Boundary-Layer Meteorology, 1992Co-Authors: Constantinos KittasAbstract:An experimental study of air flow near the walls of a greenhouse protected by a natural windbreak shows that a low speed reversed flow is produced between the two obstacles and relatively large wind speeds and gradients are located at the top of the greenhouse (Figure 1). Estimation of the convective heat fluxes from the different zones of the greenhouse cover to the surroundings shows that heat losses by convective processes are most important from the top of the greenhouse. This implies a need for good greenhouse Roof Insulation in order to save energy. On the other hand, estimation of the incoming thermal radiation over the greenhouse shows that the presence of the wind-break modifies the radiative exchanges. The hedges act as a radiative shelter. So, the heat losses of the greenhouse are reduced. This paper also shows that the adoption of an overall heat transfer coefficient for the determination of convective heat losses from the greenhouse is inaccurate, leading to an overestimation of the above losses when using such a coefficient.
Alawaththage D. Maduranga - One of the best experts on this subject based on the ideXlab platform.
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Investigating the Thermal Efficiency of Thermo-foils as a Roof Insulation Material and Developing a New Roof Insulation Material Using Coir Fiber
2020Co-Authors: Alawaththage D. MadurangaAbstract:The thermo-foil is an Insulation material which can be used to insulate Roofs of residential buildings which causes less energy to accomplish a comfortable temperature inside the building. In this study, an investigation of the efficiency of the thermo-foils in building Insulation is performed. The thermal Insulation properties and structure of the thermo-foil were analyzed as well as how these properties affect the decrease of temperature inside the residential building. The thermo-foils were tested using miniature building models for a more general conclusion. A heat transfer mechanism for a residential building is also proposed. A new Roof Insulation material is designed using an efficient and low cost natural fiber, coconut fiber or coir. The Insulation properties unique to the coir fiber are enhanced as an Insulation material. The new foil which is called Coir-Foil is tested together with thermo-foil. The Coir-Foil could achieve considerable higher performance than the currently available thermo-foil. The performance analysis for new coir foil and existing thermo-foils was used to conclude how they affect the energy conservation of residential buildings, through reducing the cooling load.
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Investigating the thermal efficiency of commercially available thermo-foils in Sri Lanka
Journal of Science of the University of Kelaniya Sri Lanka, 2012Co-Authors: Alawaththage D. Maduranga, H.h. Sumathipala, N.w.k. JayatissaAbstract:The thermo-foil is an Insulation material which can be used to insulate Roofs of residential buildings which causes less energy to accomplish a comfortable temperature inside the building. It’s becoming popular in Sri Lankan building construction sector. In this research, an investigation of the efficiency of the thermo-foils is done for commonly used brands. The important thermal properties are analyzed for thermo-foils with a thickness of 3mm, 5mm and 8mm and it is tested using a miniature building model for the further evaluation of the efficiency. It was observed that the aluminium layer of the thermo-foil could reflect most of the radiation back and the polyethylene foam layer could keep a temperature gradient of a few degrees. A temperature drop of 1.6 to 2.8 degrees was noted. The results obtained were discussed with an analysis of the thermal Insulation properties. A heat transfer model for a residential building was also proposed. Keywords: Thermo – foils; Thermal conductivity; polyethylene foam; Roof Insulation DOI: http://dx.doi.org/10.4038/josuk.v6i0.4217 J Sci.Univ.Kelaniya 6 (2011) : 01-12
Anders C. Schmidt - One of the best experts on this subject based on the ideXlab platform.
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A comparative Life Cycle assessment of building Insulation products made of stone wool, paper wool and flax
The International Journal of Life Cycle Assessment, 2004Co-Authors: Anders C. Schmidt, Allan A. Jensen, Anders U. Clausen, Ole Kamstrup, Dennis PostlethwaiteAbstract:Insulation of buildings in order to save heating energy is an important technology for enabling sustainable development. This paper summarises the results of a comparative LCA study according to ISO 14040 standard series of HT stone wool, flax representing crop grown products and paper wool representing recycled products applied for Roof Insulation. As the three materials have vastly different lifecycles, yet fulfil the same function cycles, the methodology used should be of general interest. Part 1 consists of the project background, goal and scope definition, a detailed life cycle inventory analysis with sensitivity analysis, impact assessment and interpretation. The actual comparison of the results from the life cycle assessments of the three products, in which an attempt is made to answer the question of whether the biological products flax and paper wool are more environmentally preferable than the mineral product stone wool representing more traditional Insulation materials, is discussed in Part 2.
