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- 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.
- Human thermo-physiological sensation control based in the adaptive comfort philosophyPublication . Conceição, E. Z. E.; Farinho, J. P.; Lúcio, Maria Manuela Jacinto do RosárioIn order to improve the building thermal efficiency, increase the human thermal comfort level and to reduce the building energy consumption, in this work, the human thermo-physiological sensation control, based in the adaptive comfort philosophy, is applied. In this control methodology the occupants, during a lesson activity, can choose among the clothing level, the activity level and the natural ventilation system. The PMV and PPD indexes are used in the numerical simulation. This work is made in a classroom school building, in the Algarve region, with Mediterranean characteristics, in Spring conditions, based in air temperature and relative humidity measurements. The comparison of the human thermal comfort level without and with control strategies is made. The obtained results are used to define an applicable activity, clothing and ventilation strategy, during the day.
- Numerical simulation of passive and active solar strategies in buildings with complex topologyPublication . Conceição, E. Z. E.; Lúcio, Maria Manuela Jacinto do RosárioIn this paper a numerical software, that simulates the building thermal behaviour with complex topology in transient conditions, was developed and used in the study of kindergarten thermal response and the occupants' thermal comfort and air quality in Mediterranean conditions. In this numerical model a new building three-dimensional grid generation philosophy, closer to the reality, that considers the building and the surrounding buildings used in the long and short-wave calculus, the external and internal shading devices, the energy and mass balance integral equations philosophy generated by the building geometry, the equation system resolution done by the Runge-Kutta-Felberg with error control and the human thermal comfort level evaluated through human thermo-physiology, are developed. In the simulation, with a real occupation cycle, the compartments, the building opaque bodies, the building transparent bodies, and the external shading devices were considered. In passive strategies the kindergarten is equipped with multiple inclined aluminium shading devices placed above the transparent windows level and in front to the transparent door facing south, removable inclined tissue shading devices placed in front to the transparent windows facing east, and horizontal fabrics shading devices placed above the transparent panel levels facing south, south-west and west. In this study, made with natural and forced ventilation, the summer and winter conditions were used. In summer conditions, the forced ventilation active strategies in all spaces with cold air from the external environment during the night, and in occupied spaces with stored cold air from the underground space were used. In winter conditions forced ventilation from an internal greenhouse, to heat the internal occupied cold spaces, was used.
- Application of a school building thermal response numerical model in the evolution of the adaptive thermal comfort level in the mediterranean environmentPublication . Conceição, E. Z. E.; Nunes, A. R. L.; Gomes, João; Lúcio, Maria Manuela Jacinto Do RosárioIn this paper, a review is made of the adaptive thermal comfort model This is then applied and compared with the performance of the conventional thermal comfort model for a school located in a Mediterranean weather environment Measurement data, combined with a building thermal response numerical model, are used to define the comfort performance under ambient natural ventilation and passive conditions for various classrooms These results can then be used to identify the locations that require further measures to improve comfort, such as extra passive heat load and shading measures The school design is based on that of an actual school and consists of three buildings, with 94 rooms Envelope construction consists of opaque panels, 307 glazed window units and concrete floors and ceilings The adaptive method uses external and internal environmental variables Input data include occupation pattern and ventilation strategies External environmental variables include air temperature, relative humidity, wind velocity and wind direction Internal parameters include occupancy cycle, occupant activity level, clothing level, airflow rate and flow velocity Indoor ventilation conditions are based on the airflow rate and the air velocity values measured in real classrooms Environmental thermal comfort conditions were evaluated, in all occupied spaces, using the PMV index method of the Fanger model corrected with the adaptive model
- Numerical simulation of the application of solar radiant systems, internal airflow and occupants' presence in the improvement of comfort in winter conditionsPublication . Conceição, E. Z. E.; Lúcio, Maria Manuela Jacinto do RosárioIn this work, the use of numerical simulation in the application of solar radiant systems, internal airflow and occupants' presence in the improvement of comfort in winter conditions is made. The thermal comfort, the local thermal discomfort and the air quality in an occupied chamber space are evaluated. In the experimental measurements, a wood chamber, a desk, two seats, two seated hygro-thermal manikins, a warm radiant floor, a solar radiation simulator and a water solar collector are used. The air velocity and the air temperature fluctuation are experimentally evaluated around 15 human body sections. The chamber surface temperature is experimentally measured. In the numerical simulation, a coupling human thermal comfort (HTC) integral model, a computational fluids dynamics (CFD) differential model and a building thermal response (BTR) integral model are applied. The human thermal comfort level is evaluated by the HTC numerical model. The airflow inside the virtual chamber, using the k-epsilon and RNG turbulence models, is evaluated by the CFD numerical model. The chamber surface and the collector temperatures are evaluated by the BTR numerical model. In the human thermal comfort level, in non-uniform environments, the predicted mean vote (PMV) and the predicted percentage of dissatisfied (PPD) people are numerically evaluated; in the local thermal discomfort level the draught risk (DR) is experimentally and numerically analyzed; and in the air quality, the carbon dioxide CO2 concentration is numerically calculated. In the validation tests, the experimental and numerical values of the chamber surface temperature, the air temperature, the air velocity, the air turbulence intensity and the DR are presented.
- Predicting the air quality, thermal comfort and draught risk for a virtual classroom with desk-type personalized ventilation systemsPublication . Conceição, Eusébio; Santiago, Cristina I. M.; Lúcio, Maria Manuela Jacinto do Rosário; Awbi, Hazim B.This paper concerns the prediction of indoor air quality (IAQ), thermal comfort (TC) and draught risk (DR) for a virtual classroom with desk-type personalized ventilation system (PVS). This numerical study considers a coupling of the computational fluid dynamics (CFD), human thermal comfort (HTC) and building thermal behavior (BTB) numerical models. The following indexes are used: the predicted percentage of dissatisfied people (PPD) index is used for the evaluation of the TC level; the carbon dioxide (CO2) concentration in the breathing zone is used for the calculation of IAQ; and the DR level around the occupants is used for the evaluation of the discomfort due to draught. The air distribution index (ADI), based in the TC level, the IAQ level, the effectiveness for heat removal and the effectiveness for contaminant removal, is used for evaluating the performance of the personalized air distribution system. The numerical simulation is made for a virtual classroom with six desks. Each desk is equipped with one PVS with two air terminal devices located overhead and two air terminal devices located below the desktop. In one numerical simulation six occupants are used, while in another simulation twelve occupants are considered. For each numerical simulation an air supply temperature of 20 degrees C and 24 degrees C is applied. The results obtained show that the ADI value is higher for twelve persons than for six persons in the classroom and it is higher for an inlet air temperature of 20 degrees C than for an inlet air temperature of 24 degrees C. In future works, more combinations of upper and lower air terminal devices located around the body area and more combinations of occupants located in the desks will be analyzed.
- Numerical Study of the Influence of Opaque External Trees with Pyramidal Shape on the Thermal Behaviour of a School Building in Summer ConditionsPublication . Conceição, E. Z. E.; Lúcio, Maria Manuela Jacinto do RosárioThis paper describes a numerical study of the influence of opaque external trees with pyramidal shape on the thermal behaviour of a school building in Summer conditions. The software used simulates the thermal response of buildings with complex topology under transient conditions. This software has previously been validated by real studies both in Summer and Winter conditions. The school building considered is localised in the South of Portugal. It has three levels divided into 97 rooms or spaces, 1277 main structures and 211 windows with plain transparent glass. In the model, the building is shaded by 49 "opaque'' trees of pyramidal shape growing in front of the windows on one side of each building considered. The simulation considered a typical Summer school day with clear sky and with 800 occupants in the building. Two situations with the same configuration were analysed. In the first one, the trees (located in front of the windows) were placed to the West and South-West of the buildings, while in the second one, after a 180 degrees building rotation, they were to the East and North-East. Both situations were studied with and without the presence of trees. Temperatures in the building and the occupant's thermal comfort conditions were calculated.
- Heating, ventilating and air conditioning systems control based in the Predicted Mean Vote indexPublication . Conceição, E. Z. E.; 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 application of Heating, Ventilating and Air Conditioning (HVAC) systems control, based in the Predicted Mean Vote (PMV) index, in the energy and thermal comfort performance in a kindergarten school building, in the South of Portugal, in Winter conditions. In the control the PMV index, based in the mean air temperature, the mean air velocity, the mean air relative humidity, the mean radiant temperature, the clothing level and the activity level, are used. In the numerical simulation of the kindergarten, 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.
- Evaluation of indoor air quality in classrooms equipped with cross-flow ventilationPublication . Conceição, E. Z. E.; Farinho, J. P.; Lúcio, Maria Manuela Jacinto do RosárioIn this work the evaluation of indoor air quality in a classroom equipped with cross-flow ventilation is presented. A numerical methodology, based on comparison with experimental data, used in the evaluation of the air exchange rate, airflow rate and the age of the air, was applied in the first phase of this work. The evolution of carbon dioxide inside spaces, with different airflow typologies, was then predicted in the second part. The study was based on a school located in the South of Portugal. In the experimental methodology the tracer gas decay method was applied. In order to reduce the experimental time, the first minutes of the test were measured, while the remaining decay was obtained using a numerical exponential regression. Natural and forced cross-flow ventilation topologies were analyzed. In the case of forced ventilation, fresh air from the external environment was driven into the classroom through an air inlet using a supply fan. An extract strategy was also used in which stale air was mechanically extracted from the classroom. Natural ventilation consisted of opening perimeter and above-door windows. The forecast of carbon dioxide evolution was made using software that evaluates the thermal response of and air quality in a building with complex topology. The numerical model used to evaluate internal air quality was based on energy and mass conservation integral equations. These were solved using the Runge-Kutta-Fehlberg method with error control.