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- Evaluation of thermal comfort conditions in a classroom equipped with radiant cooling systems and subjected to uniform convective environmentPublication . Conceição, E. Z. E.; Lucio, M. M. J. R.The aim of this work is to evaluate numerically the human thermal response that 24 students and 1 teacher feel in a classroom equipped with radiant cooling systems and subjected to uniform convective environments, in lightly warm conditions. The evolution of thermal comfort conditions, using the PMV index, is made by the multi-nodal human thermal comfort model. In this numerical model, that works in transient or steady-state conditions and simulates simultaneously a group of persons, the three-dimensional body is divided in 24 cylindrical and 1 spherical elements. Each element is divided in four parts (core, muscle, fat and skin), sub-divided in several layers, and protected by several clothing layers. This numerical model is divided in six parts: human body thermal system, clothing thermal system, integral equations resolution system, thermoregulatory system, heat exchange between the body and the environment and thermal comfort evaluation. Seven different radiant systems are combined to three convective environments. In the radiant systems (1) no radiant system without warmed curtain, (2) no radiant system with warmed curtain, (3) radiant floors cooling system with warmed curtain, (4) radiant panels cooling system with warmed curtain, (5) radiant ceiling cooling system with warmed curtain, (6) radiant floor and panels cooling system with warmed curtain and (7) radiant ceiling and panels cooling system with warmed curtain are analysed, while in the convective environments (1) without air velocity field and with uniform air velocity field of (2) 0.2 m/s and (3) 0.6 m/s are also analysed. The internal air temperature and internal surfaces temperature are 28 degrees C, the radiant cooling surfaces temperature are 19 degrees C and the warmed internal curtains surfaces temperatures, subjected to direct solar radiation, are 40 degrees C. The numerical model calculates the Mean Radiant Temperature field, the human bodies' temperatures field and the thermal comfort level, for the 25 occupants, for the 21 analysed situations. Without uniform air velocity field, when only one individual radiant cooling system is used, the Predicted Percentage of Dissatisfied people is lowest when the radiant floor cooling system is applied and is highest when the radiant panel cooling system is applied. When are combined the radiant ceiling or the floor cooling systems with the radiant panel cooling system the Predicted Percentage of Dissatisfied people decreases. When the uniform air velocity increases the thermal comfort level, that the occupants are subjected, increases. When the radiant floor cooling system or the combination of radiant floor and panel cooling systems without uniform air velocity field is applied, the Category C is verified for some occupants. However, with a convective uniform air velocity field of 0.2 m/s the Category B is verified and with a convective uniform air velocity field of 0.6 m/s the Category A is verify for some occupants. In the last situation the Category C is verified, in general, for all occupants. (C) 2010 Elsevier Inc. All rights reserved.
- Application of computational fluid dynamics differential model coupled with human thermal comfort integral model in ventilated indoor spacesPublication . Conceição, E. Z. E.; Geraldo, D. R. B.; Lúcio, Maria Manuela Jacinto do RosárioIn this study the coupling of computational fluid dynamics (CFD) differential and human thermal comfort (HTC) integral numerical models is developed and used. The HTC integral numerical model evaluates the thermal comfort in non-uniform environments, while the CFD differential numerical model evaluates the airflow inside the virtual chamber and around the manikins. The numerical simulation, using upper crossed ventilation and made in winter conditions, is applied inside a virtual chamber equipped with two seated manikins, one desk and two seats. In this simulation the numerical airflow values, obtained with two different computational grid discretization with one and two manikins, are compared with experimental measurements. Copyright © 2011 by IPAC'11/EPS-AG.
- Fast determination of the acoustic area of influence of roads, railways, airports and industriesPublication . Rosão, Vitor; Rosão, C.; Conceição, E. Z. E.It is very important to know, as early as possible, what is the acoustic area of influence of a particular project, because this information has influence in other areas, e.g. The extension of cartography necessary. So, it is relevant to find fast and simple methods to determine the acoustic area of influence, based on European Interim Methods, for roads, railways, airports and industries.
- Application of an indoor greenhouse in the energy and thermal comfort performance in a kindergarten school building in the South of Portugal in winter conditionsPublication . Conceição, E. Z. E.; Lucio, M. M. J. R.; Lopes, M. C.In this work a numerical model, which simulates the buildings thermal response and evaluates the indoor environment comfort, in transient conditions, is used in the application of an indoor greenhouse in the energy and thermal comfort performance in a kindergarten school building, in the South of Portugal, in Winter conditions. 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 two schools and three residential surrounding main buildings, are considered. This numerical model is applied in the evaluation of the kindergarten thermal behavior, using the indoor temperature field, and the occupants thermal comfort levels, using the PMV and PPD indexes. After to be compared the numerical and experimental indoor air temperatures field and identified the indoor thermal uncomfortable spaces, the numerical model is used in the evaluation of the indoor greenhouse performance, in order to increase the indoor air temperature and thermal comfort levels, using solar renewable energy, without increase of the kindergarten energy consumption. It is analyzed in detail the greenhouse ventilation operating time and the warm airflow transport way, using an internal ducts system or a corridor space, from the greenhouse to the indoor coldest spaces.
- Variability of noise levels from railwaysPublication . Rosão, Vitor; Conceição, E. Z. E.; Marques, T.The purpose of this study is to determine the variability of noise levels associated with the pass-by of the same type of train at a point, near a railway, and compare this variability with the standard uncertainty, due to the operation of the source, established in ISO 1996-2: 2007, and in the document "Determination of Lden and Lnigth Using Measurements: 2006", from the European Work Group IMAGINE. With these results we can know the measurement effort required to achieve a certain standard uncertainty.
- 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.
- Energy and thermal comfort evaluation for different passive solutions in a kindergarten in summer conditionsPublication . Conceição, E. Z. E.; Lopes, M. C.; Lucio, M. M. J. R.In this work a numerical model, which simulates the buildings thermal response with complex topology and evaluates the indoor environment comfort, in transient conditions, is used in the energy and thermal comfort evaluation for different passive solutions in a kindergarten, in Summer conditions. After the validation phase, this numerical model is applied in the evaluation of the building thermal behaviour, using the indoor temperature field, and the occupants' thermal comfort levels, using the PMV and PPD indexes. The introduction of a roof placed in the top of the kindergarten, horizontal shading devices placed above the windows level facing South and external pyramidal opaque trees placed in front to the windows facing West and East, used to reduce the indoor temperature level and to increase the indoor thermal comfort level, in Summer conditions, are analyzed.
- 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.
- Evaluation of thermal comfort conditions in a localized radiant system placed in front and behind two students seated nearby warmed curtainsPublication . Conceição, E. Z. E.; Lucio, M. M. J. R.In this work the evaluation of thermal comfort conditions, that two students are subjected, in a classroom desk equipped with a localized radiant system placed in front and behind the occupants seated nearby windows equipped with curtains subjected to solar radiation, in Winter conditions, is made. In the simulation, performed in a 2.7 x 2.4 x 2.4 m(3) virtual chamber, two occupants seated in a classroom desk, equipped with two localized radiant surfaces placed in front and two localized radiant surfaces placed behind them, a window subjected to solar radiation and an internal curtain are considered. A numerical model, that allows to simulate the human body thermal, clothing thermal and thermoregulatory systems, in non-uniform environments, is used. The Mean Radiant Temperature, with and without correction, and Radiosity methods are used in the study of the influence of the localized radiant surface, the room surrounding surfaces, the lateral occupant's body, the lateral curtain surface and the lateral solar radiation, in the thermal comfort conditions. In the first part of the study three numerical methods used in the evaluation of internal radiant heat exchanges in an acceptable typical thermal situation are analysed, while in the second part the influence of four important thermal parameters in the thermal comfort level is analysed. In the first part of this work, the localized radiant surfaces and the lateral occupant's body are evaluated in the first test, the localized radiant surfaces, the lateral occupants body and the lateral curtains surface are evaluated in the second test and the localized radiant surfaces, the lateral occupants body, the lateral window glass surface and the lateral solar radiation are evaluated in the third test. In the second part of this work, the influence of air temperature, equal to the room surrounding surfaces temperature, the localized radiant system temperature, the lateral curtains temperature and the air relative humidity, in the thermal comfort level, that the two occupants are subjected, is evaluated. (C) 2010 Elsevier Ltd. All rights reserved.
- Method to determine the speed of vehicles by means of noise levels variationPublication . Rosão, Vitor; Conceição, E. Z. E.; Házyová, L.Statistical Pass-By Index is a parameter defined on ISO 11819-1: 1997, that pretends to measure the influence of road surfaces on traffic noise. One of the base parameters of this index is speed of vehicles on the road. The present paper shows a method to determine the speed of vehicles on the road using the shape of noise levels variations, and shows the improvement that this method can give one the selection of most correct pass-by levels.
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