The aim of this work is to observe the flow reversal that can appear at the time of interaction of hot and cold boundary layers in transient mixed convection in a vertical pipe.The instationary character of the flow is due to the application at the entry of the tube of a positive or negative temperature step. The transient mixed convection has a significant contribution in many industrial applications such as the air conditioning systems, the heat exchangers, nuclear plants, etc.
In France, for historical and demographic reasons, many educational buildings must be retrofitted in the next years.However, various studies showed that measurements of energy savings, and improvement of comfort, are rarely applied in the retrofitting operations, because of a lack of knowledge of the decision makers concerning the potential improvements.The program REDUCE of International Energy Agency - ECBCS Annex 36, and studies aiming at promoting the high environmental quality of the educational buildings in France, showed the existence of a potential improvement of the energy efficie
The SOLVENT window is an innovative glazing system concept that involves the use of a rotating frame, an absorptive glazing and a naturally ventilated vertical channel, in order to improve the balance between the visual comfort and the energy efficiency of windows.
Meteorological measurements required for the development of a design scheme that responds to the local environment are generally recorded by the weather service in stations that are assumed to be representative of the surrounding region. However, no account is taken of the changes in conditions caused by urban development, even though differences between meteorological conditions within cities compared with adjacent rural areas (the heat island effect) may be substantial.
This project presents the development of an algorithm predicting ambient greenhouse air conditions to be used for energy efficiency simulation and control schemes optimization. The climatic conditions considered are temperature, relative humidity, CO2 concentration and solar radiation. The algorithm has two modes of operation, the first simulates the greenhouse while in the second the heating, cooling, humidification or dehumidification, CO2 injection rates are calculated to maintain certain setpoints.
Experience of energy auditing of residential buildings in Latvia discovers problems with discrepancy of data measured and calculated. Analysis of dynamic changes of data presents factors, which influence results of energy audits and proposals for energy efficiency measure. Paper presents analysis of influence of solar radiation and modelling of solar factor for control of heat supply.
The severe impact on health associated with biocontaminants, such as dust mites, has become increasingly apparent in recent years. Consequently, a considerable effort has taken place to develop biocontaminant growth models and to assess the efficacy of possible psychrometric control measures, involving the modification of room conditions. However this approach is not always successful due to the low correlation between room conditions and those within the microenvironments inhabited by biocontaminants.
Application of lighting control technologies has increased the public interest. Although these technologies have been promoted during the last years their successful use in buildings has been accomplished in a small percentage of new projects. One reason is the difficulty in quantifying the energy savings and thus the subsequent payback period.
The existing buildings stock in European countries accounts for over 40% of final energy consumption in the European Union (EU) member states, of which residential use represents 63% of total energy consumption in the buildings sector. Consequently, an increase of building energy performance can constitute an important instrument in the efforts to alleviate the EU energy import dependency and comply with the Kyoto Protocol to reduce carbon dioxide emissions.
Other papers in this conference discuss the experimental requirements for high quality outdoor testing of building components and the subsequent analysis procedures for identifying key parameters that quantify performance. This is important for achieving standardised metrics that characterise the building component of interest, whether it is a passive solar component such as a ventilated window, or an active component such as a hybrid photovoltaic module.
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