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- Development of a temperature control model used in HVAC systems in school spaces in Mediterranean climatePublication . Conceição, Eusébio; Lúcio, Maria Manuela Jacinto do Rosário; Ruano, Antonio; Crispim, E. M.In this paper a temperature control model used in heating, Ventilating and air-conditioning (HVAC) systems in school spaces, in Mediterranean climate, is developed. This empirical model considers the indoor preferred environmental temperature, the outdoor environmental temperature and the adaptation to the seasons of the year and to the spaces. In the development of the empirical model, in a school building located in the Algarve region, in the South of Portugal, occupied spaces by the non-teacher staff (administrative and auxiliary), teachers and students were used. In these spaces, equipped with heating, ventilating and air-conditioning systems, the occupants can change, during one year of school activities, the indoor environmental conditions in order to obtain acceptable comfort conditions. The indoor air temperature and relative humidity inside four spaces, namely an office room, a secretary room, a teachers room and a library room, the outdoor air temperature and other parameters related to the spaces and heating, ventilating and air-conditioning systems were measured every minute during one year. This empirical model, based in a group of equations for different months and for several spaces, gives information that can be used in the control of a heating, ventilating and air-conditioning systems, in school spaces, in Mediterranean climate, in order to promote indoor acceptable conditions with energy savings. In this model the adaptation to the outdoor environment, for different seasons, the clothing level and the fact that occupants enter and leave frequently from spaces equipped with heating, ventilating and air-conditioning systems to others not equipped are analyzed.
- Evaluation of thermal comfort in slightly warm ventilated spaces in nonuniform environmentsPublication . Conceição, E. Z. E.; Lúcio, Maria Manuela Jacinto do Rosário; Lourenço, T. M. C.; Brito, A. I. P. V.The present work analyzes and evaluates the global thermal comfort and local thermal discomfort levels of an occupant subjected to a symmetric nonuniform airflow, originated in common use ventilators. Several incident airflow directions are studied and their effects are described. The global thermal comfort level is evaluated through a multi-nodal numerical model that simulates human and clothing thermal responses, while the local thermal discomfort level is analyzed using an empirical model that predicts draft risks. The computational model of the human body and clothing thermal systems is based on the energy balance integral equations for human body tissue, blood, and clothing, as well as mass balance integral equations for the blood and transpired water in skin surface and the clothing. The human body is divided into 35 elements, each one in several layers of tissue, which could be protected through some clothing layers. A thermoregulatory system model was adapted to control the human body tissue temperature. The experimental tests were carried out in a test chamber in controlled environmental conditions; a thermal manikin was used to simulate the human posture, an indoor climate analyzer was used to measure the environmental variables around the occupant, and two ventilators were used to produce an airflow field around the occupant. The frontal and ascendant airflows from the ventilators placed in front of the occupant are characterized and their velocities around the occupant are measured for several incident angles. The global thermal comfort conditions of the occupant are evaluated both with and without ventilation, and the local thermal discomfort level is evaluated with ventilation for slightly warm, moderate environments.
- Numerical Study of the Thermal Efficiency of a School Building with Complex Topology for Different OrientationsPublication . Conceição, E. Z. E.; Lúcio, Maria Manuela Jacinto do RosárioIn this work a numerical model that simulates the thermal behavior of a building with complex topology and evaluates the indoor thermal and air quality, in transient conditions, is used for a school building thermal project. The program calculates the building surfaces solar radiation field, the building's temperatures, the internal environmental variables, and the occupant's comfort levels. Initially, after the numerical model is validated, the software is used to evaluate the school building's thermal response for four different orientations, either in winter or summer conditions. The work then aims to identify uncomfortable spaces in order to propose, as an example, several solutions that could be introduced for each orientation, that would improve the thermal comfort and air quality levels to which the occupants are subjected, and decrease the building's energy consumption levels. The information obtained from this study could be used to help a designer choose which thermal systems and solutions function best for a preferred school building orientation.
- Prediction of building's temperature using neural networks modelsPublication . Ruano, Antonio; Crispim, E. M.; Conceição, Eusébio; Lúcio, Maria Manuela Jacinto do RosárioThe use of artificial neural networks in various applications related with energy management in buildings has been increasing significantly over the recent years. In this paper the design of inside air temperature predictive neural network models, to be used for predictive control of airconditioned systems, is discussed. The use of multi-objective genetic algorithms for designing off-line radial basis function neural network models is detailed. The performance of these data-driven models is compared, favourably, with a multi-node physically based model. Climate and environmental data from a secondary school located in the south of Portugal, collected by a remote data acquisition system, are used to generate the models. By using a sliding window adaptive methodology, the good results obtained off-line are extended throughout the whole year. The use of long-range predictive models for airconditioning systems control is demonstrated, in simulations, achieving a good temperature regulation with important energy savings.
- Energy and thermal comfort management in a kindergarten school building in the South of Portugal in Winter conditionsPublication . Conceição, E. Z. E.; Lopes, M. C.; Lúcio, Maria Manuela Jacinto do RosárioIn this work a numerical model, which simulates the buildings thermal response and evaluates the indoor environment comfort, in transient conditions, is used in the energy and thermal comfort management in a kindergarten school building in the South of Portugal in Winter conditions. After it's validation, this numerical model is applied in the evaluation of the building thermal behavior, using the indoor temperature field, and the occupants thermal comfort levels, using the PMV and PPD indexes. In the numerical model validation, experimental data and numerical values, for the indoor air temperature, are compared. In the experimental tests, for a typical Winter day, the outdoor and indoor environmental variables are measured. In the numerical simulation of the kindergarten school building, the 25 compartments, the 498 building main bodies and the 42 windows glasses, as well as all surrounding main buildings, are considered. The viability to build an indoor greenhouse, used to heat the cooled spaces, and the evolution of indoor thermal comfort level are analyzed.