This work presents the first step of the development of a new concept of photovoltaic/ thermal collector that will be combined with preheating air and/or water production. It consists in a simplified mathematical modeling of a PV/T air collector. The studied prototype is a component of metal sheet type which has an air gap at the backside and which can be integrated in roofs or in facades.
Natural ventilation is one of the most efficient passive cooling techniques for buildings. Knowledge of the wind speed in street canyons is the necessary condition for the application of such a technique in dense urban configurations. Thus, prediction techniques to evaluate the microclimate and dispersion parameters in street canyons, has become a subject of intense scientific research. In most cases, wind flow and pollutant dispersion characteristics have been studied numerically and experimentally.
Windows are considered an important factor for comfort in residential and commercial buildings. Research turned to window technology when it was realized that poor thermal characteristics resulted in serious energy and economical consumption and pollution. Following an experimental campaign, which was carried out in a PASSYS test cell which provided a complete data base, a fuzzy system was developed and tested theoretically in order to control an electrochromic glazing in the best possible way. Concerning the theoretical part a model was developed in the MATLAB SIMULINK environment.
The first part of the paper gives criticisms of convetional practice in landscape architecture in hot humids climates, in terms or efficient utilization of energy. Basic criticisms are: overdependence on imports, oversize of open spaces, oversize of exposed potable water, inappropriate irrigation systems, inappropiate use of plants, and mismanagement of natural resources. The second part of the paper gives recommendations for energy efficient landscape architecture in hot humids regions.
The amount of waste produced every year, the exhaustion of resources and the construction solutions currently used in construction may not be sustainable in the future. All these issues lead to the research on new construction techniques, on recycling of waste into useful materials, on re-use of construction materials, etc.
Rawshans has been one of the traditional architectural devices that are still being used in recent buildings as an environmental controlling device. Beside their use as an architectural component, they have been used to control natural ventilation and light. The most critical portion of the Rawshan, as light control concern, is the front screen. A systematic analysis of this portion has not yet been taken care of. However, pervious work of this component was investigated by the author for the effect of direct sunlight transmission.
The growing demand for better environmental conditions, especially in offices, has increased the need for appropriate standard in order to success the maximum productivity, to minimize the problems of health and the functional cost of air-condition systems. The purpose of this study is to investigate the thermal environment in offices of occupants in University of Patras.
The article shows the results of a case study dealing with indoor daylighting concepts and practice. The analysis evaluates the performances of different window options taking into account quantitative and qualitative aspects such as daylight factor, uniformity ratio of illuminance, and daylighting glare index.
Defrosting in supermarket refrigeration systems is normally controlled by a preset time cycle with most display cabinets timed to defrost every 6 hours. It is widely acknowledged that timed defrost may cause a number of unnecessary defrost cycles and this reduces the energy efficiency of refrigeration systems as well as the accuracy of temperature control of the cases.
It has been shown by previous researchers that Artificial Neural Networks (ANNs) not only be used to predict energy more reliably than traditional simulation models and regression techniques but can also from the basis for a predictive controller of thermal systems such as HVAC equipment. This work is directed towards the identification of the important inputs (independent variables) to facilitate on-line prediction and thereby implement refrigeration and HVAC system diagnostics, process control, optimisation and energy management in retail food stores.
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