- Email: [email protected]
01253 Space temperature difference, cooling coil and fan-energy and indoor air quality issues revisited
13 Space heating and cooling especially an adsorption icemaker prototype in the laboratory. The better perspectives of applications for the lattermost exist in fishing vessels.
merits. These aims, examined within the legislative and market framework, are discussed in this paper, both as criteria for evaluating state of the art materials and as goals for future research developments.
05/01251
05/01255 Study of the thermal behaviour of traditional wine cellars: the case of the area of 'Tierras Sorianas del Cid' (Spain)
Roof cooling effect with humid porous medium
Meng, Q. and Hu, W. Energy and Buildings, 2005, 37, (1), 1-9. A method of laying a layer of humid porous medium on roof to gain free cooling effect by passive water evaporation is proposed. Numeric model for simulating cooling effect is built with the help of experimental results of physical properties for humid porous medium, which shows advantage over analytical solutions because of the supposition of constant physical properties in the latter. Through the comparison between simulated and experimental results, the model is validated. The method of evaporation cooling effect with humid porous medium on the roof is tested to be feasible.
05/01252 Social anthropological and interdisciplinary research on the conversion of electrically heated single family houses to heating by combined pellet-solar systems Henning, A. Biomass and Bioenergy, 2004, 27, (6), 547-555. The social anthropological research presented here is part of the interdisciplinary research project PESTO, which focuses on the (partial or complete) conversion of single family houses from electric heating to heating by combined pellet-solar heating systems. Basic to this research is the assumption that it is more likely that energy conversions are carried through, and that they are successful on a long-term basis, if the new products are designed to fit as well as possible into the everyday lives of people. The anthropological interest in the project can be divided into two parts; motives for or against a conversion among men and women in Swedish households, and product design and placement in (previously) electrically heated single-family houses. Literature studies and semi-structured qualitative interviews are the main methods used in the anthropological part of the project. During the next 3-year project period, these investigations will be used to support information and marketing, and to formulate recommendations for conversion practice of electrically heated single-family houses to combined pellet-solar heating.
05/01253 Space temperature difference, cooling coil and fan-energy and indoor air quality issues revisited Sekhar, S. C. Energy and Buildings, 2005, 37, (1), 49-54. In designing an energy-efficient air-conditioning system that also simultaneously addresses the needs of adequate ventilation and acceptable indoor air quality, several factors begin to play an important role. Among several others, the cooling coil, the fan and the temperature difference between the space and the supply air (commonly known as the Space AT) can be considered to be crucial. For a given space cooling load, the choice of a particular Space A T has an implication on the amount of supply air required, which further has an impact on the performance of the cooling and dehumidifying coil as well as the fan. Inherent in these implications are issues related to energy, ventilation and indoor air quality. This paper investigates these implications and quantifies them by considering a hypothetical building in a tropical climate and subjecting the design to several parametric variations involving different Space ATs for a given space temperature and humidity condition. The total power requirements, comprising additional cooling, reheating and higher fan power, for a design involving a Space A T of 5°C can be as high as a factor of 2.2 of the total power for a design with a Space A T of 8°C. The implication of higher supply air flow rates on duct design is qualitatively discussed. For a given space cooling load and a given Space AT, the implication of increased design ventilation rates to address part-load ventilation requirements can lead to an additional installed cooling capacity of 17.5%. Finally, emerging technologies that are aimed at addressing both energy efficiency and IAQ are discussed.
05/01254 State of the art in thermal insulation materials and aims for future developments Papadopoulos, A. M. Energy and Buildings, 2005, 37, (1), 77-86. Insulation materials are the key tool in designing and constructing energy-thrifty buildings. This is demonstrated by the increasing thicknesses used in buildings, which also reflects in the growing sales of the branch. The European market of insulation materials is characterized by the domination of two groups of products inorganic fibrous materials and organic foamy materials. They all feature similar performance in terms of insulating capabilities, but otherwise present significant differences. These are discussed in detail in the following paper. Despite the fact that the thermal properties of the materials have not improved significantly of the last decade, a series of other features, like reaction to fire and moisture or mechanical properties have improved, sometimes even at the cost of insulation abilities. Furthermore, environmental and public health aspects play an increasing role, both in the search for 'optimum' materials for given applications, and in the aims set by the industry for future develop-
186
Fuel and Energy Abstracts May 2005
Guerrero, I. C. and Ocafia, S. M. Renewable Energy, 2005, 30, (1), 4355. This article studies the hygro-thermal behaviour of two traditional underground wine cellars from Morcuera (Soria, Spain). The differences between them arc analysed and the hypothesis is that one of these constructions is better than the other for the ageing of wines. The hypothesis takes into consideration the existence of a temperature difference of over 2°C between them as a basis for reaching the aforementioned conclusion. However, the relative humidity inside both of them is 100%, which could pose problems if the presence of mould is not controlled. This study is based on fieldwork for the inventory and cataloguing of traditional agrarian constructions in the 'Tierras Sorianas' area. The objective of this investigation is to highlight some advantages of traditional building techniques over modern construction practices from the energy-saving viewpoint.
05/01256 The design and experimental characterisation of an asymmetric compound parabolic photovoltaic concentrator for building facade integration in the UK Mallick, T. K. et al. Solar Energy, 2004, 77, (3), 319-327. A novel non-imaging asymmetric compound parabolic photovoltaic concentrator (ACPPVC) has been designed, constructed and experimentally characterized at the University of Ulster, Northern Ireland (54°36+N, 5°37'W). Different numbers of PV strings connected in series were experimentally characterized under outdoor conditions both with and without concentrators. Transient I - V curves for each set of parameter data points were determined and the maximum power generation, fill factor and efficiency of the system calculated for each individual I - V curve. Experiments showed that the use of an ACPPVC increased the maximum power point by 62% (i.e. the power by a factor of 1.62) when compared to a similar non-concentrafing PV panel.
05•01257 The effect of perceived indoor air quality on productivity loss Kosonen, R. and Tan, F. Energy and Buildings, 2004, 36, (10), 981-986. This theoretical study reports on the impact of perceived indoor air quality for productivity loss in air-conditioned office buildings. A new derivation of productivity calculation model based on pollution loads and contaminant removal effectiveness is applied and the effect of the improved ventilation efficiency on productivity is estimated. The findings show that the proportion dissatisfied is a good predictor of productivity loss due to indoor air quality in different kinds of office work. It is possible to calculate the proportion dissatisfied from olf and decipol units. Productivity is possible to improve by increasing outdoor airflow rate, decreasing emissions and improving ventilation efficiene3~ e.g. with displacement ventilation. In a case of one person per I0 m ~ (0.1 olf/m 2) and low-emitted material (0.1 olf/m2), the total sensory pollution load is 0.2 olffm2. Normally, the minimum admissible outdoor airflow rate is 0.5-1.5 l/s per m 2 in office spaces. This means that 5-9% productivity loss should be accepted using the minimum airflow rate design method. With displacement ventilation, it is possible to improve indoor air quality in a manner that significantly increases productivity compared with traditional mixing system. The effect of the contaminant removal effectiveness on the productivity loss is about 0.5-2% between these systems using the same airflow rate.
05/01258 The influence of heat resistance and heat leak on the performance of a four-heat-reservoir absorption refrigerator with heat transfer law of Q ~ A ( T 1) Zheng, T. et al. International Journal of Thermal Sciences, 2004, 43, (12), 1187-1195. On the basis of an endo-reversible absorption refrigeration cycle model with Newton's heat transfer law, an irreversible four-heat-reservoir cycle model with another linear heat transfer law of Qc~2x(7~l) is built by taking account the heat leak and heat resistance losses. The fundamental optimal relation between the coefficient of performance (COP) and the cooling load, the maximum COP and the corresponding cooling load, as well as the maximum cooling load and the corresponding COP of the cycle with another linear heat transfer law coupled to constant-temperature heat reservoirs are derived by using finite-time thermodynamics. The optimal distribution relation of the heat-transfer surface areas is also obtained. Moreover, the effects of the cycle parameters on the COP and the cooling load of the cycle are studied by detailed numerical examples. The results obtained herein are of importance to the optimal design and performance improvement of a four-heat-reservoir absorption refrigeration cycle.
merits. These aims, examined within the legislative and market framework, are discussed in this paper, both as criteria for evaluating state of the art materials and as goals for future research developments.
05/01251
05/01255 Study of the thermal behaviour of traditional wine cellars: the case of the area of 'Tierras Sorianas del Cid' (Spain)
Roof cooling effect with humid porous medium
Meng, Q. and Hu, W. Energy and Buildings, 2005, 37, (1), 1-9. A method of laying a layer of humid porous medium on roof to gain free cooling effect by passive water evaporation is proposed. Numeric model for simulating cooling effect is built with the help of experimental results of physical properties for humid porous medium, which shows advantage over analytical solutions because of the supposition of constant physical properties in the latter. Through the comparison between simulated and experimental results, the model is validated. The method of evaporation cooling effect with humid porous medium on the roof is tested to be feasible.
05/01252 Social anthropological and interdisciplinary research on the conversion of electrically heated single family houses to heating by combined pellet-solar systems Henning, A. Biomass and Bioenergy, 2004, 27, (6), 547-555. The social anthropological research presented here is part of the interdisciplinary research project PESTO, which focuses on the (partial or complete) conversion of single family houses from electric heating to heating by combined pellet-solar heating systems. Basic to this research is the assumption that it is more likely that energy conversions are carried through, and that they are successful on a long-term basis, if the new products are designed to fit as well as possible into the everyday lives of people. The anthropological interest in the project can be divided into two parts; motives for or against a conversion among men and women in Swedish households, and product design and placement in (previously) electrically heated single-family houses. Literature studies and semi-structured qualitative interviews are the main methods used in the anthropological part of the project. During the next 3-year project period, these investigations will be used to support information and marketing, and to formulate recommendations for conversion practice of electrically heated single-family houses to combined pellet-solar heating.
05/01253 Space temperature difference, cooling coil and fan-energy and indoor air quality issues revisited Sekhar, S. C. Energy and Buildings, 2005, 37, (1), 49-54. In designing an energy-efficient air-conditioning system that also simultaneously addresses the needs of adequate ventilation and acceptable indoor air quality, several factors begin to play an important role. Among several others, the cooling coil, the fan and the temperature difference between the space and the supply air (commonly known as the Space AT) can be considered to be crucial. For a given space cooling load, the choice of a particular Space A T has an implication on the amount of supply air required, which further has an impact on the performance of the cooling and dehumidifying coil as well as the fan. Inherent in these implications are issues related to energy, ventilation and indoor air quality. This paper investigates these implications and quantifies them by considering a hypothetical building in a tropical climate and subjecting the design to several parametric variations involving different Space ATs for a given space temperature and humidity condition. The total power requirements, comprising additional cooling, reheating and higher fan power, for a design involving a Space A T of 5°C can be as high as a factor of 2.2 of the total power for a design with a Space A T of 8°C. The implication of higher supply air flow rates on duct design is qualitatively discussed. For a given space cooling load and a given Space AT, the implication of increased design ventilation rates to address part-load ventilation requirements can lead to an additional installed cooling capacity of 17.5%. Finally, emerging technologies that are aimed at addressing both energy efficiency and IAQ are discussed.
05/01254 State of the art in thermal insulation materials and aims for future developments Papadopoulos, A. M. Energy and Buildings, 2005, 37, (1), 77-86. Insulation materials are the key tool in designing and constructing energy-thrifty buildings. This is demonstrated by the increasing thicknesses used in buildings, which also reflects in the growing sales of the branch. The European market of insulation materials is characterized by the domination of two groups of products inorganic fibrous materials and organic foamy materials. They all feature similar performance in terms of insulating capabilities, but otherwise present significant differences. These are discussed in detail in the following paper. Despite the fact that the thermal properties of the materials have not improved significantly of the last decade, a series of other features, like reaction to fire and moisture or mechanical properties have improved, sometimes even at the cost of insulation abilities. Furthermore, environmental and public health aspects play an increasing role, both in the search for 'optimum' materials for given applications, and in the aims set by the industry for future develop-
186
Fuel and Energy Abstracts May 2005
Guerrero, I. C. and Ocafia, S. M. Renewable Energy, 2005, 30, (1), 4355. This article studies the hygro-thermal behaviour of two traditional underground wine cellars from Morcuera (Soria, Spain). The differences between them arc analysed and the hypothesis is that one of these constructions is better than the other for the ageing of wines. The hypothesis takes into consideration the existence of a temperature difference of over 2°C between them as a basis for reaching the aforementioned conclusion. However, the relative humidity inside both of them is 100%, which could pose problems if the presence of mould is not controlled. This study is based on fieldwork for the inventory and cataloguing of traditional agrarian constructions in the 'Tierras Sorianas' area. The objective of this investigation is to highlight some advantages of traditional building techniques over modern construction practices from the energy-saving viewpoint.
05/01256 The design and experimental characterisation of an asymmetric compound parabolic photovoltaic concentrator for building facade integration in the UK Mallick, T. K. et al. Solar Energy, 2004, 77, (3), 319-327. A novel non-imaging asymmetric compound parabolic photovoltaic concentrator (ACPPVC) has been designed, constructed and experimentally characterized at the University of Ulster, Northern Ireland (54°36+N, 5°37'W). Different numbers of PV strings connected in series were experimentally characterized under outdoor conditions both with and without concentrators. Transient I - V curves for each set of parameter data points were determined and the maximum power generation, fill factor and efficiency of the system calculated for each individual I - V curve. Experiments showed that the use of an ACPPVC increased the maximum power point by 62% (i.e. the power by a factor of 1.62) when compared to a similar non-concentrafing PV panel.
05•01257 The effect of perceived indoor air quality on productivity loss Kosonen, R. and Tan, F. Energy and Buildings, 2004, 36, (10), 981-986. This theoretical study reports on the impact of perceived indoor air quality for productivity loss in air-conditioned office buildings. A new derivation of productivity calculation model based on pollution loads and contaminant removal effectiveness is applied and the effect of the improved ventilation efficiency on productivity is estimated. The findings show that the proportion dissatisfied is a good predictor of productivity loss due to indoor air quality in different kinds of office work. It is possible to calculate the proportion dissatisfied from olf and decipol units. Productivity is possible to improve by increasing outdoor airflow rate, decreasing emissions and improving ventilation efficiene3~ e.g. with displacement ventilation. In a case of one person per I0 m ~ (0.1 olf/m 2) and low-emitted material (0.1 olf/m2), the total sensory pollution load is 0.2 olffm2. Normally, the minimum admissible outdoor airflow rate is 0.5-1.5 l/s per m 2 in office spaces. This means that 5-9% productivity loss should be accepted using the minimum airflow rate design method. With displacement ventilation, it is possible to improve indoor air quality in a manner that significantly increases productivity compared with traditional mixing system. The effect of the contaminant removal effectiveness on the productivity loss is about 0.5-2% between these systems using the same airflow rate.
05/01258 The influence of heat resistance and heat leak on the performance of a four-heat-reservoir absorption refrigerator with heat transfer law of Q ~ A ( T 1) Zheng, T. et al. International Journal of Thermal Sciences, 2004, 43, (12), 1187-1195. On the basis of an endo-reversible absorption refrigeration cycle model with Newton's heat transfer law, an irreversible four-heat-reservoir cycle model with another linear heat transfer law of Qc~2x(7~l) is built by taking account the heat leak and heat resistance losses. The fundamental optimal relation between the coefficient of performance (COP) and the cooling load, the maximum COP and the corresponding cooling load, as well as the maximum cooling load and the corresponding COP of the cycle with another linear heat transfer law coupled to constant-temperature heat reservoirs are derived by using finite-time thermodynamics. The optimal distribution relation of the heat-transfer surface areas is also obtained. Moreover, the effects of the cycle parameters on the COP and the cooling load of the cycle are studied by detailed numerical examples. The results obtained herein are of importance to the optimal design and performance improvement of a four-heat-reservoir absorption refrigeration cycle.