The need for a decrease in the energy consumption of buildings implies an adequate understanding ... more The need for a decrease in the energy consumption of buildings implies an adequate understanding of control strategies. This requires an intensive use of simulation tools for the design and test of controllers of HVAC equipment. It is noticed that simulation software commonly used in control engineering do not provide any model of HVAC equipment. The SIMBAD project has been set up to develop a toolbox of such models adapted to the needs in the control field. As the toolbox is mainly conceived for users who are not necessarily "experts" in HVAC equipment, the user-friendliness of the models is a major concern in the development work. This includes a hierarchical structure for the description of systems, an insight of physical phenomena involved in the models visible on the graphical interface, an enhanced parametering mode and availability of parameters of models.
The «positive energy building 3 concept combines energy saving and electricity production using r... more The «positive energy building 3 concept combines energy saving and electricity production using renewable resources, aiming a positive primary energy balance on a yearly basis. Compared to other concepts of high energy performance buildings, it is very ambitious on an energy point of view, but more materials and components are used, this is why the environmental relevance of this concept has to be questioned.
The Passive House Standard, green and sustainable buildings, which have a descent history as well... more The Passive House Standard, green and sustainable buildings, which have a descent history as well as being currently developed, will play a key role to reduce or slow down the development of global warming. My main focus in this thesis is on Passive Houses and the problems following when constructing in cold climates and if it is possible to expand the Passive House market to more extreme climates than exist in central Europe. The conclusion made here is that it is achievable to reach the Passive House Standard in a cold climate, especially when taking location, orientation, windows area, insulation and the heat recovery of the ventilation system into consideration from the very start of each project. In an even harsher climate a special addition to the Passive House, a stove, could help to come close to its standard. Even though the actual Passive House Standard will be hard to achieve and most likely quite costly, a building close to this standard will still have its benefits for the residents of the house as well as the environment and that should be the focus for the future.
Mines ParisTech : 60, bd Saint-Michel 75272 PARIS CEDEX 06 [email protected] RESUME. Un bâ... more Mines ParisTech : 60, bd Saint-Michel 75272 PARIS CEDEX 06 [email protected] RESUME. Un bâtiment constitué de deux maisons individuelles mitoyennes, répondant au standard allemand « Passivhaus », a été réalisé en 2007 à Formerie (Oise). Ce bâtiment a été modélisé et son comportement thermique simulé à l'aide du logiciel de simulation dynamique des bâtiments COMFIE. Afin de prendre en compte son système de ventilationcomprenant un échangeur air-sol et un récupérateur sur air vicié -un modèle a été spécifiquement développé et intégré à COMFIE. Dans cet article, le comportement de ce bâtiment passif a été simulé, de même que celui d'un bâtiment analogue répondant seulement aux exigences de la réglementation thermique française RT2005. Les besoins de chauffage et le confort thermique des deux bâtiments sont comparés, puis un bilan environnemental, réalisé à l'aide de l'outil d'analyse de cycle de vie EQUER, montre les performances du standard Passivhaus en terme de consommation d'énergie primaire, de réchauffement climatique et de divers autres impacts. Dans le contexte français, le concept passif constitue une solution pour améliorer les performances énergétiques et environnementales des bâtiments.
... (4) The evaluation of the ... of the thermo-active building system with closed-loop thermosta... more ... (4) The evaluation of the ... of the thermo-active building system with closed-loop thermostatic control of the variable-air volume (VAV) ventilation system as sketched in ... The building is equipped with an air-cooled reciprocating chiller with a nominal capacity of CCAP nom = 500 kW ...
... Numerical Evaluation of Earth to Air Heat Exchangers and Heat Recovery Ventilation Systems. .... more ... Numerical Evaluation of Earth to Air Heat Exchangers and Heat Recovery Ventilation Systems. ... coupling an earth to air heat exchanger to a balanced ventilation system is rather ... reduction, earth to air heat exchanger, passive cooling, mechanical ventilation systems, heat recovery ...
... Finally, the environmental assessment carried out with the life cycle assessment tool EQUER... more ... Finally, the environmental assessment carried out with the life cycle assessment tool EQUER shows the reduction in primary energy consumption, global warming potential and other impacts brought by the passive house design. ...
An air-to-earth heat exchanger (ATEHE) consists of pipes buried in soil. We have evaluated the te... more An air-to-earth heat exchanger (ATEHE) consists of pipes buried in soil. We have evaluated the technical and economic performance of an ATEHE coupled to the system for heating or cooling of a building that uses 100% fresh air as heating or cooling medium during winter and summer. The soil is divided into elementary layers. The problem solved, is non stationary; however, steady state-energy equations are used for soil layers in each time step. It is found that the use of the ATEHE covers a portion of the daily building needs for space ...
A simplified analytical model is developed to study the year round effectiveness of a recirculati... more A simplified analytical model is developed to study the year round effectiveness of a recirculation type earth air heat exchanger coupled with a greenhouse located in IIT Delhi, India. The performance of the system was evaluated in terms of thermal load leveling and coefficient of performance. Calculations were done for typical winter and summer day in year 2002. Temperatures of greenhouse air were found to be on an average 6-7 °C more in winter and 3^1 °C less in summer than the same greenhouse when operating without earth air heat exchanger. Predicted and measured values of greenhouse air temperatures exhibited fair agreement.
A thermal model has been developed to investigate the potential of using the stored thermal energ... more A thermal model has been developed to investigate the potential of using the stored thermal energy of the ground for greenhouse heating and cooling with the help of an earth to air heat exchanger (EAHE) system integrated with the greenhouse located in the premises of IIT, Delhi, India. Experiments were conducted extensively throughout the year 2003, but the developed model was validated against typical clear and sunny days experiments. Parametric studies performed for the EAHE coupled with the greenhouse illustrate the effects of buried pipe length, pipe diameter, mass flow rate of air, depth of ground and types of soil on the greenhouse air temperatures. The temperatures of the greenhouse air, with the experimental parameters of the EAHE, were found to be, on average 7-8°C higher in the winter and 5-6°C lower in the summer than those of the same greenhouse without the EAHE. The greenhouse air temperatures increase in the winter and decrease in the summer with increasing pipe length, decreasing pipe diameter, decreasing mass flow rate of flowing air inside buried pipe and increasing depth of ground up to 4 m. The predicted and measured values of the greenhouse air temperatures that were verified, in terms of root mean square percent deviation and correlation coefficient, exhibited fair agreement.
A theoretical model of an earth-air heat exchanger (EAHE) is developed for predicting the outlet ... more A theoretical model of an earth-air heat exchanger (EAHE) is developed for predicting the outlet air temperature and cooling potential of these devices in a hot, arid climate. The model is validated against other published models and shows good agreement. A sub-soil temperature model adapted for the specific conditions in Kuwait is presented and its output compared with measurements in two locations. A building model representative of a typical Kuwaiti dwelling has been implemented and all the models have been encoded within the TRNSYS-IISIBAT environment. A typical meteorological year for Kuwait was prepared and used to predict the cooling loads of the air-conditioned dwelling with and without the assistance of the EAHE. Simulation results showed that the EAHE could provide a reduction of 1700 W in the peak cooling load, with an indoor temperature reduction of 2.8 1C during summer peak hours (middle of July). The EAHE is shown to have the potential for reducing cooling energy demand in a typical house by 30% over the peak summer season. r
In designing an earth-to-air heat exchanger (EAHX), a decision on design goals has to be made. If... more In designing an earth-to-air heat exchanger (EAHX), a decision on design goals has to be made. If the air flow is given by the ventilation system and the construction site is known, the question is: is it more important to achieve a high specific energy performance based on the surface area of an EAHX, a high adoption of air temperature to ground temperature or a very small pressure loss? This paper deals with the performance of three EAHXs for mid European office buildings in service, with the aim of characterising their efficiency. A general method to compare EAHXs in operation will be introduced. First, the temperature behaviour is described by plots over time and characteristic lines, and compared by standardised duration curves. Second, the energy gain is illustrated by standardised graphs. Third, a parametric model is used to provide general efficiency criteria. Thermal efficiency should be defined by both the dynamic temperature behaviour and energy performance.
A new complete numerical model for the prediction of thermal performance of the earth-to-air heat... more A new complete numerical model for the prediction of thermal performance of the earth-to-air heat exchangers is presented. The model describes the simultaneous heat and mass transfer inside the tube and into the soil accounting for the soil natural thermal stratification. The ...
Three different green technologies are compared in terms of net energy and carbon savings for a t... more Three different green technologies are compared in terms of net energy and carbon savings for a theoretical Toronto rooftop. Embodied energy values are calculated through Life Cycle Analysis and compared to the estimated energies produced and/or saved by each technology. Results show that solar photovoltaics displace the most carbon per m 2 of roof space and solar thermal (for hot water) displaces the most energy. An in-depth analysis of an intensive green roof for growing food indicates that the high embodied energy of the materials is not quickly repaid by the sum of six energy savings that were examined (direct and indirect cooling, run-off treatment, transport of food, on-farm energy use, and activities that would otherwise be carried out). However, the energy and carbon benefits are not insignificant, but depend strongly on various assumptions.
Journal of Building Performance Simulation, Jan 1, 2009
... emission of greenhouse gases, expressed in terms of annual carbon dioxide equivalent ... of t... more ... emission of greenhouse gases, expressed in terms of annual carbon dioxide equivalent ... of the instantaneous fuel mix for electricity generation on the corresponding emissions. ... University of Wisconsin, Solar Energy Laboratory (SEL), Madison, USA, and TRANSSOLAR, Stuttgart ...
The need for a decrease in the energy consumption of buildings implies an adequate understanding ... more The need for a decrease in the energy consumption of buildings implies an adequate understanding of control strategies. This requires an intensive use of simulation tools for the design and test of controllers of HVAC equipment. It is noticed that simulation software commonly used in control engineering do not provide any model of HVAC equipment. The SIMBAD project has been set up to develop a toolbox of such models adapted to the needs in the control field. As the toolbox is mainly conceived for users who are not necessarily "experts" in HVAC equipment, the user-friendliness of the models is a major concern in the development work. This includes a hierarchical structure for the description of systems, an insight of physical phenomena involved in the models visible on the graphical interface, an enhanced parametering mode and availability of parameters of models.
The «positive energy building 3 concept combines energy saving and electricity production using r... more The «positive energy building 3 concept combines energy saving and electricity production using renewable resources, aiming a positive primary energy balance on a yearly basis. Compared to other concepts of high energy performance buildings, it is very ambitious on an energy point of view, but more materials and components are used, this is why the environmental relevance of this concept has to be questioned.
The Passive House Standard, green and sustainable buildings, which have a descent history as well... more The Passive House Standard, green and sustainable buildings, which have a descent history as well as being currently developed, will play a key role to reduce or slow down the development of global warming. My main focus in this thesis is on Passive Houses and the problems following when constructing in cold climates and if it is possible to expand the Passive House market to more extreme climates than exist in central Europe. The conclusion made here is that it is achievable to reach the Passive House Standard in a cold climate, especially when taking location, orientation, windows area, insulation and the heat recovery of the ventilation system into consideration from the very start of each project. In an even harsher climate a special addition to the Passive House, a stove, could help to come close to its standard. Even though the actual Passive House Standard will be hard to achieve and most likely quite costly, a building close to this standard will still have its benefits for the residents of the house as well as the environment and that should be the focus for the future.
Mines ParisTech : 60, bd Saint-Michel 75272 PARIS CEDEX 06 [email protected] RESUME. Un bâ... more Mines ParisTech : 60, bd Saint-Michel 75272 PARIS CEDEX 06 [email protected] RESUME. Un bâtiment constitué de deux maisons individuelles mitoyennes, répondant au standard allemand « Passivhaus », a été réalisé en 2007 à Formerie (Oise). Ce bâtiment a été modélisé et son comportement thermique simulé à l'aide du logiciel de simulation dynamique des bâtiments COMFIE. Afin de prendre en compte son système de ventilationcomprenant un échangeur air-sol et un récupérateur sur air vicié -un modèle a été spécifiquement développé et intégré à COMFIE. Dans cet article, le comportement de ce bâtiment passif a été simulé, de même que celui d'un bâtiment analogue répondant seulement aux exigences de la réglementation thermique française RT2005. Les besoins de chauffage et le confort thermique des deux bâtiments sont comparés, puis un bilan environnemental, réalisé à l'aide de l'outil d'analyse de cycle de vie EQUER, montre les performances du standard Passivhaus en terme de consommation d'énergie primaire, de réchauffement climatique et de divers autres impacts. Dans le contexte français, le concept passif constitue une solution pour améliorer les performances énergétiques et environnementales des bâtiments.
... (4) The evaluation of the ... of the thermo-active building system with closed-loop thermosta... more ... (4) The evaluation of the ... of the thermo-active building system with closed-loop thermostatic control of the variable-air volume (VAV) ventilation system as sketched in ... The building is equipped with an air-cooled reciprocating chiller with a nominal capacity of CCAP nom = 500 kW ...
... Numerical Evaluation of Earth to Air Heat Exchangers and Heat Recovery Ventilation Systems. .... more ... Numerical Evaluation of Earth to Air Heat Exchangers and Heat Recovery Ventilation Systems. ... coupling an earth to air heat exchanger to a balanced ventilation system is rather ... reduction, earth to air heat exchanger, passive cooling, mechanical ventilation systems, heat recovery ...
... Finally, the environmental assessment carried out with the life cycle assessment tool EQUER... more ... Finally, the environmental assessment carried out with the life cycle assessment tool EQUER shows the reduction in primary energy consumption, global warming potential and other impacts brought by the passive house design. ...
An air-to-earth heat exchanger (ATEHE) consists of pipes buried in soil. We have evaluated the te... more An air-to-earth heat exchanger (ATEHE) consists of pipes buried in soil. We have evaluated the technical and economic performance of an ATEHE coupled to the system for heating or cooling of a building that uses 100% fresh air as heating or cooling medium during winter and summer. The soil is divided into elementary layers. The problem solved, is non stationary; however, steady state-energy equations are used for soil layers in each time step. It is found that the use of the ATEHE covers a portion of the daily building needs for space ...
A simplified analytical model is developed to study the year round effectiveness of a recirculati... more A simplified analytical model is developed to study the year round effectiveness of a recirculation type earth air heat exchanger coupled with a greenhouse located in IIT Delhi, India. The performance of the system was evaluated in terms of thermal load leveling and coefficient of performance. Calculations were done for typical winter and summer day in year 2002. Temperatures of greenhouse air were found to be on an average 6-7 °C more in winter and 3^1 °C less in summer than the same greenhouse when operating without earth air heat exchanger. Predicted and measured values of greenhouse air temperatures exhibited fair agreement.
A thermal model has been developed to investigate the potential of using the stored thermal energ... more A thermal model has been developed to investigate the potential of using the stored thermal energy of the ground for greenhouse heating and cooling with the help of an earth to air heat exchanger (EAHE) system integrated with the greenhouse located in the premises of IIT, Delhi, India. Experiments were conducted extensively throughout the year 2003, but the developed model was validated against typical clear and sunny days experiments. Parametric studies performed for the EAHE coupled with the greenhouse illustrate the effects of buried pipe length, pipe diameter, mass flow rate of air, depth of ground and types of soil on the greenhouse air temperatures. The temperatures of the greenhouse air, with the experimental parameters of the EAHE, were found to be, on average 7-8°C higher in the winter and 5-6°C lower in the summer than those of the same greenhouse without the EAHE. The greenhouse air temperatures increase in the winter and decrease in the summer with increasing pipe length, decreasing pipe diameter, decreasing mass flow rate of flowing air inside buried pipe and increasing depth of ground up to 4 m. The predicted and measured values of the greenhouse air temperatures that were verified, in terms of root mean square percent deviation and correlation coefficient, exhibited fair agreement.
A theoretical model of an earth-air heat exchanger (EAHE) is developed for predicting the outlet ... more A theoretical model of an earth-air heat exchanger (EAHE) is developed for predicting the outlet air temperature and cooling potential of these devices in a hot, arid climate. The model is validated against other published models and shows good agreement. A sub-soil temperature model adapted for the specific conditions in Kuwait is presented and its output compared with measurements in two locations. A building model representative of a typical Kuwaiti dwelling has been implemented and all the models have been encoded within the TRNSYS-IISIBAT environment. A typical meteorological year for Kuwait was prepared and used to predict the cooling loads of the air-conditioned dwelling with and without the assistance of the EAHE. Simulation results showed that the EAHE could provide a reduction of 1700 W in the peak cooling load, with an indoor temperature reduction of 2.8 1C during summer peak hours (middle of July). The EAHE is shown to have the potential for reducing cooling energy demand in a typical house by 30% over the peak summer season. r
In designing an earth-to-air heat exchanger (EAHX), a decision on design goals has to be made. If... more In designing an earth-to-air heat exchanger (EAHX), a decision on design goals has to be made. If the air flow is given by the ventilation system and the construction site is known, the question is: is it more important to achieve a high specific energy performance based on the surface area of an EAHX, a high adoption of air temperature to ground temperature or a very small pressure loss? This paper deals with the performance of three EAHXs for mid European office buildings in service, with the aim of characterising their efficiency. A general method to compare EAHXs in operation will be introduced. First, the temperature behaviour is described by plots over time and characteristic lines, and compared by standardised duration curves. Second, the energy gain is illustrated by standardised graphs. Third, a parametric model is used to provide general efficiency criteria. Thermal efficiency should be defined by both the dynamic temperature behaviour and energy performance.
A new complete numerical model for the prediction of thermal performance of the earth-to-air heat... more A new complete numerical model for the prediction of thermal performance of the earth-to-air heat exchangers is presented. The model describes the simultaneous heat and mass transfer inside the tube and into the soil accounting for the soil natural thermal stratification. The ...
Three different green technologies are compared in terms of net energy and carbon savings for a t... more Three different green technologies are compared in terms of net energy and carbon savings for a theoretical Toronto rooftop. Embodied energy values are calculated through Life Cycle Analysis and compared to the estimated energies produced and/or saved by each technology. Results show that solar photovoltaics displace the most carbon per m 2 of roof space and solar thermal (for hot water) displaces the most energy. An in-depth analysis of an intensive green roof for growing food indicates that the high embodied energy of the materials is not quickly repaid by the sum of six energy savings that were examined (direct and indirect cooling, run-off treatment, transport of food, on-farm energy use, and activities that would otherwise be carried out). However, the energy and carbon benefits are not insignificant, but depend strongly on various assumptions.
Journal of Building Performance Simulation, Jan 1, 2009
... emission of greenhouse gases, expressed in terms of annual carbon dioxide equivalent ... of t... more ... emission of greenhouse gases, expressed in terms of annual carbon dioxide equivalent ... of the instantaneous fuel mix for electricity generation on the corresponding emissions. ... University of Wisconsin, Solar Energy Laboratory (SEL), Madison, USA, and TRANSSOLAR, Stuttgart ...
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Papers by Khatib Rim