Gas-fired radiant heaters

This dissertation covers four areas of particular interest for the successful application of radiant heating in industrial environments. In it the author tackles the problem of how to predict the thermal comfort produced both by single heaters and also systems of heaters; proposes a method for modelling the mechanisms by which heaters interact with the buildings in which they are installed, in the static and dynamic cases; explores techniques for measuring the radiation produced by heaters; and presents experiments concerned with finding the temperatures and power balances prevailing during normal operation. It is contended that, whilst the generally accepted guides for sizing and operating space heating plant were a good first approximation, there are intrinsic subtleties arising from the fact that the primary mode of heat transfer in this instance is radiative. These nuances are concerned with how best to maximise the heat transfer from the heat source to the heated object; the placement of heaters within a system; and an assessment of the various techniques and strategies involved in controlling a radiant heating system. The conclusions reached are that: if sized and controlled correctly radiant heating systems offer considerable operational advantages over other types of space heating systems in certain applications, in terms of both economy and controllability. The efficacy of radiant heating systems is affected primarily by the control strategy implemented; secondarily, by the structure of the building into which it is installed; and only marginally by all other factors.

Recanto do vale do pium: condomínio de habitações com ênfase no baixo impacto ambiental e no desempenho térmico do ambiente construído

This work describes the design process of a small recreational gated community in Pium, Nísia Floresta/RN, from concept to final design stages, with emphasis on low environmental impact, thermal comfort and the spatial quality of housing. The process consisted in a review of the literature and relevant standards, studies of design references and architectural programming. The project development was initially focused on the project’s feasibility, with the definition of the number of units, implantation, size and location of the dwellings and the common areas of the development. Two types of houses (four low rise and five duplex units) have been proposed in order to attend the premises of architectural programming. The conception of the architectural design began with the rooms’ zoning according to the lots. This resulted in the pre-selection of three alternatives that were evaluated in terms of spatial quality and environmental performance. The development of sketches focused on the envelope consistent with the bioclimatic guidelines and on the language of the compatible proposal with the lowest possible environmental impact of the building system, which resulted in the selection of the eucalyptus wood type. During the working drawings, the Quality Technical Regulation for the Level of Energy Efficiency Residential Buildings (RTQ -R) was adopted for the evaluation of the envelope, which resulted in "B" level of efficiency for the first case. After minor adjustments, mainly in frames, the efficiency level rose to "A", demonstrating that early project decisions contributed to the envelope energy performance. Besides the design of the two types of units, the final proposal of the gated community includes the design of the equipment for the common areas (entrance, multipurpose room and support and service sector), and the descriptive texts explaining the project and construction’s details.

Arquitetura bioclimática para instituição de ensino fundamental em São Gonçalo do Amarante/RN

In the design of a building process must consider climatic variations in the region, the external conditions and the use of available resources in nature, like the sun, vegetation, rain and winds, to provide a built environment with comfort and environment reduced energy expenditure. However, increasing urbanization, often with an occupancy of disordered ground comes disregarding this knowledge and disregarding local characteristics, drastically reducing the green areas. This disordered occupation associated with the reduction of green spaces, is modifying aspects of climate and thus, damaging the thermal comfort of users. Given this situation was born the question: What projetuais strategies can bring better thermal conditions to an educational building located in a region of hot and humid weather? Thus, faced with two important issues , education and environmental comfort , the research is justified by the fact that there is a large national demand for expansions and renovations in its public schools , but not in most areas provides students with quality for good learning development. This paper aims to draw up a project for establishment of Primary Education with the application of the concepts of bioclimatic, highlighting the use of vegetation as a regulatory element of the climate. Initially we carried out a literature search; we analyzed architectural solutions and set up the site. The next phases, called understanding, were raised with the laws, rules and environmental restrictions. Subsequently, the program needs and the development of architectural design was defined. The conclusion of this paper presents the definition of criteria and solutions for the use of vegetation to design of bioclimatic architecture in hot and humid climates and contributes a catalog of plant species for schools in the metropolitan region of Natal, RN.

Vernaculares: a casa de fazenda seridoense do século XIX como exemplo de adaptação ao clima semiárido

The farm’s rural dwellings of creation from the Seridó Potiguar microregion, built in the nineteenth century, became a reference by its vernacular character, i.e. these buildings, besides having recognized relevance to the identity of the region, they are adapted to the conditions of the place in many aspects (economic, cultural, construction, physical, et.) and consist in protective spaces in relation to hostile characteristics of Seridó’s climate. Considering the above premise, the following question arises: What characteristics of the nineteenth century Seridó Potiguar’s cattle farms are crucial for them to be a protective space in relation to the semiarid climate? In order to answer the question, this research aim to identify which particularities of the Seridó’s farmhouses that contribute to adaptability in these buildings to semiarid climate, as protection environments; and contribute to the stock valuation of the architectural heritage concerned. Therefore, procedures were adopted divided into two stages. Were first identified the recurring characteristics in the studied buildings, through typological study performed from existing inventories (DINIZ, 2008; FEIJÓ, 2002; IPHAN, 2012). To define the type it worked up with the concept that merges Durand’s analytical typology that identifies the similarities and differences to classify buildings, having the character of historical survey and architectural documentation, with the definition proposed by Argan (1963) that the type is not defined a priory, but the deduction from a number of illustrative cases which have formal and functional similarity with each other. Then worked up in a sample of five different types with each other, defined by the possibility of access to the interior of the houses, proximity to other copies, good state of conservation and preservation. The contemplated farms were: Pitombeiras, Agenus e Garrotes in Acari’s town, and the municipality of Caicó, Palma and Penedo. The second stage consists of the architectural survey, photographic record, digital three-dimensional modeling (aiming to expand the existing documentation and registration) and thermal monitoring over approximately a representative day in five farmhouses, relating the thermal performance of the houses with their individual characteristics. The selected variables for analysis monitoring are based on the thermal comfort adaptive model (SPAGNOLO and DE DEAR, 2003 apud NEGREIROS, 2010). The characteristics of the houses were analyzed as meeting the passive thermal conditioning strategies recommended by NBR 15220 (ABNT, 2005), for the bioclimatic zone 7 where the municipalities of Caicó and Acari are located. The house’s analysis of the operating temperatures revealed that 90% of the times of day the environments are within the comfort range. The farmhouses, which had a higher degree of compliance with recommended bioclimatic strategies, had the best thermal performance. In environments (usually the kitchen and rooms with low ceiling heights, exposed to west radiation) which still had discomfort hours, the thermal comfort can be reached with air movement approximately 1,0 m/s.

Vernaculares: a casa de fazenda seridoense do século XIX como exemplo de adaptação ao clima semiárido

The farm’s rural dwellings of creation from the Seridó Potiguar microregion, built in the nineteenth century, became a reference by its vernacular character, i.e. these buildings, besides having recognized relevance to the identity of the region, they are adapted to the conditions of the place in many aspects (economic, cultural, construction, physical, et.) and consist in protective spaces in relation to hostile characteristics of Seridó’s climate. Considering the above premise, the following question arises: What characteristics of the nineteenth century Seridó Potiguar’s cattle farms are crucial for them to be a protective space in relation to the semiarid climate? In order to answer the question, this research aim to identify which particularities of the Seridó’s farmhouses that contribute to adaptability in these buildings to semiarid climate, as protection environments; and contribute to the stock valuation of the architectural heritage concerned. Therefore, procedures were adopted divided into two stages. Were first identified the recurring characteristics in the studied buildings, through typological study performed from existing inventories (DINIZ, 2008; FEIJÓ, 2002; IPHAN, 2012). To define the type it worked up with the concept that merges Durand’s analytical typology that identifies the similarities and differences to classify buildings, having the character of historical survey and architectural documentation, with the definition proposed by Argan (1963) that the type is not defined a priory, but the deduction from a number of illustrative cases which have formal and functional similarity with each other. Then worked up in a sample of five different types with each other, defined by the possibility of access to the interior of the houses, proximity to other copies, good state of conservation and preservation. The contemplated farms were: Pitombeiras, Agenus e Garrotes in Acari’s town, and the municipality of Caicó, Palma and Penedo. The second stage consists of the architectural survey, photographic record, digital three-dimensional modeling (aiming to expand the existing documentation and registration) and thermal monitoring over approximately a representative day in five farmhouses, relating the thermal performance of the houses with their individual characteristics. The selected variables for analysis monitoring are based on the thermal comfort adaptive model (SPAGNOLO and DE DEAR, 2003 apud NEGREIROS, 2010). The characteristics of the houses were analyzed as meeting the passive thermal conditioning strategies recommended by NBR 15220 (ABNT, 2005), for the bioclimatic zone 7 where the municipalities of Caicó and Acari are located. The house’s analysis of the operating temperatures revealed that 90% of the times of day the environments are within the comfort range. The farmhouses, which had a higher degree of compliance with recommended bioclimatic strategies, had the best thermal performance. In environments (usually the kitchen and rooms with low ceiling heights, exposed to west radiation) which still had discomfort hours, the thermal comfort can be reached with air movement approximately 1,0 m/s.

Caracterização de um compósito utilizando cimento com agregado de resíduo plástico e resíduo de gesso

The demand for environmental comfort in construction systems within the insulation and thermal comfort, plus the advent of new laws regulating the minimum requirements of comfort, disposal of solid industrial waste, construction waste, the requirements of consumers by adopting construction methods "cleaner", encouraged the development of this work. Aims technologically characterize the composite proposed in three types of samples (10%, 30% and 50% of thermoset plastic industrial waste) and raw materials: gypsum waste, cement and plastic thermosetting industrial waste in order to produce the composite with properties of thermal insulation: conductivity, thermal diffusivity, specific heat and resistivity. The physical, structural and morphological properties of the raw materials were investigated by thermogravimetry analysis (TG / DSC), X-ray diffraction (DRX), X-ray fluorescence (FXR) and scanning electron microscopy (MEV). Obtaining mechanical properties through the compression strength test. The analysis results indicate characteristics suitable for cement matrix composite production with the addition of thermosetting plastic industrial waste and gypsum waste, with potential application of these materials in composites with properties of thermal insulation. Finally, assessing what proportion showed up with better performance. Considering the analysis and testing carried out.

Caracterização de um compósito utilizando cimento com agregado de resíduo plástico e resíduo de gesso

The demand for environmental comfort in construction systems within the insulation and thermal comfort, plus the advent of new laws regulating the minimum requirements of comfort, disposal of solid industrial waste, construction waste, the requirements of consumers by adopting construction methods "cleaner", encouraged the development of this work. Aims technologically characterize the composite proposed in three types of samples (10%, 30% and 50% of thermoset plastic industrial waste) and raw materials: gypsum waste, cement and plastic thermosetting industrial waste in order to produce the composite with properties of thermal insulation: conductivity, thermal diffusivity, specific heat and resistivity. The physical, structural and morphological properties of the raw materials were investigated by thermogravimetry analysis (TG / DSC), X-ray diffraction (DRX), X-ray fluorescence (FXR) and scanning electron microscopy (MEV). Obtaining mechanical properties through the compression strength test. The analysis results indicate characteristics suitable for cement matrix composite production with the addition of thermosetting plastic industrial waste and gypsum waste, with potential application of these materials in composites with properties of thermal insulation. Finally, assessing what proportion showed up with better performance. Considering the analysis and testing carried out.

Building performance evaluation of domestic energy efficient retrofits in current and future climates

Approximately half of the houses in Northern Ireland were built before any form of minimum thermal specification or energy efficiency standard was enforced. Furthermore, 44% of households are categorised as being in fuel poverty; spending more than 10% of the household income to heat the house to bring it to an acceptable level of thermal comfort. To bring existing housing stock up to an acceptable standard, retrofitting for improving the energy efficiency is essential and it is also necessary to study the effectiveness of such improvements in future climate scenarios. This paper presents the results from a year-long performance monitoring of two houses that have undergone retrofits to improve energy efficiency. Using wireless sensor technology internal temperature, humidity, external weather, household gas and electricity usage were monitored for a year. Simulations using IES-VE dynamic building modelling software were calibrated using the monitoring data to ASHARE Guideline 14 standards. The energy performance and the internal environment of the houses were then assessed for current and future climate scenarios and the results show that there is a need for a holistic balanced strategy for retrofitting.

Survery and simulation of energy use in the European building stock

the work towards increased energy efficiency. In order to plan and perform effective energy renovation of the buildings, it is necessary to have adequate information on the current status of the buildings in terms of architectural features and energy needs. Unfortunately, the official statistics do not include all of the needed information for the whole building stock.   This paper aims to fill the gaps in the statistics by gathering data from studies, projects and national energy agencies, and by calibrating TRNSYS models against the existing data to complete missing energy demand data, for countries with similar climate, through simulation. The survey was limited to residential and office buildings in the EU member states (before July 2013). This work was carried out as part of the EU FP7 project iNSPiRe.   The building stock survey revealed over 70% of the residential and office floor area is concentrated in the six most populated countries. The total energy consumption in the residential sector is 14 times that of the office sector. In the residential sector, single family houses represent 60% of the heated floor area, albeit with different share in the different countries, indicating that retrofit solutions cannot be focused only on multi-family houses.   The simulation results indicate that residential buildings in central and southern European countries are not always heated to 20 °C, but are kept at a lower temperature during at least part of the day. Improving the energy performance of these houses through renovation could allow the occupants to increase the room temperature and improve their thermal comfort, even though the potential for energy savings would then be reduced.

Análise bioclimática do bairro do Renascença II São Luis-MA: realidade e perspectiva do conforto térmico em espaços externos

The present research concerns about outdoor s thermal comfort conditions in hot-humid climate cities, understanding that life quality is a result of the urban object s type built for the human being in an environment with specific climate and morphological characteristics. It is presented as object of study the correlation between the neighborhood Renascença II s microclimate in São Luis /MA-Brazil, hot-humid climate city, and its urban morphological changes. As well as the thermal comfort s satisfaction level of its outdoor users. The research has as general goal to diagnosis the way these transformations caused by the urbanization influence the Renascença II s microclimate, identifying critical spots of the studied area, in order to contribute with land use recommendations based on bioclimatic architecture concepts and supply bases to urban design decisions adequate to the São Luis climate. It is presented as theoretical bases the urban climate, its concepts and elements. After that, the thermal comfort conditioners and its prediction models of thermal comfort sensation in outdoor are presented. The predictive models are presented along with bioclimatic assessment methods. Finally the use of bioclimatic assessment as an effective tool to identify places that need changes or preservation in order to seek environment quality. The applied methodology was based on the studies of Katzschner (1997), complemented by Oliveira s (1988) and Bustos Romero s (2001) studies that suggest an analysis and evaluation of maps of topography, buildings floors, land use, green areas and land covering, in order to overlap their characteristics and identify climate variable s measurements points; then a quantitative analysis of the climate variables (air temperature and humidity, wind speed and direction) of the chosen points takes place. It was perceived that Renaissance II has no permanence areas as squares or parks, its outdoor has little vegetation and presets high land impermeability and built density levels. The majority of the people interviewed said that was comfortable in a range of air temperature between 27,28ºC and 30,71ºC. The elaboration of a neighborhood master plan is important, which defines strategies for improvement of the life quality of its inhabitants

Análise de métodos para aplicação de ventilação natural em projetos de edificações em Natal-RN

Natural ventilation is an efficient bioclimatic strategy, one that provides thermal comfort, healthful and cooling to the edification. However, the disregard for quality environment, the uncertainties involved in the phenomenon and the popularization of artificial climate systems are held as an excuse for those who neglect the benefits of passive cooling. The unfamiliarity with the concept may be lessened if ventilation is observed in every step of the project, especially in the initial phase in which decisions bear a great impact in the construction process. The tools available in order to quantify the impact of projected decisions consist basically of the renovation rate calculations or computer simulations of fluids, commonly dubbed CFD, which stands for Computational Fluid Dynamics , both somewhat apart from the project s execution and unable to adapt for use in parametric studies. Thus, we chose to verify, through computer simulation, the representativeness of the results with a method of simplified air reconditioning rate calculation, as well as making it more compatible with the questions relevant to the first phases of the project s process. The case object consists of a model resulting from the recommendations of the Código de Obras de Natal/ RN, customized according to the NBR 15220. The study has shown the complexity in aggregating a CFD tool to the process and the need for a method capable of generating data at the compatible rate to the flow of ideas and are discarded during the project s development. At the end of our study, we discuss the necessary concessions for the realization of simulations, the applicability and the limitations of both the tools used and the method adopted, as well as the representativeness of the results obtained

Utilização de um aplicativo de simulação computacional na avaliação de desempenho térmico de protótipo de habitação de interesse social (his)

This Masters Degree dissertation seeks to make a comparative study of internal air temperature data, simulated through the thermal computer application DesignBuilder 1.2, and data registered in loco through HOBO® Temp Data Logger, in a Social Housing Prototype (HIS), located at the Central Campus of the Federal University of Rio Grande do Norte UFRN. The prototype was designed and built seeking strategies of thermal comfort recommended for the local climate where the study was carried out, and built with panels of cellular concrete by Construtora DoisA, a collaborator of research project REPESC Rede de Pesquisa em Eficiência Energética de Sistemas Construtivos (Research Network on Energy Efficiency of Construction Systems), an integral part of Habitare program. The methodology employed carefully examined the problem, reviewed the bibliography, analyzing the major aspects related to computer simulations for thermal performance of buildings, such as climate characterization of the region under study and users thermal comfort demands. The DesignBuilder 1.2 computer application was used as a simulation tool, and theoretical alterations were carried out in the prototype, then they were compared with the parameters of thermal comfort adopted, based on the area s current technical literature. Analyses of the comparative studies were performed through graphical outputs for a better understanding of air temperature amplitudes and thermal comfort conditions. The data used for the characterization of external air temperature were obtained from the Test Reference Year (TRY), defined for the study area (Natal-RN). Thus the author also performed comparative studies for TRY data registered in the years 2006, 2007 and 2008, at weather station Davis Precision Station, located at the Instituto Nacional de Pesquisas Espaciais INPE-CRN (National Institute of Space Research), in a neighboring area of UFRN s Central Campus. The conclusions observed from the comparative studies performed among computer simulations, and the local records obtained from the studied prototype, point out that the simulations performed in naturally ventilated buildings is quite a complex task, due to the applications limitations, mainly owed to the complexity of air flow phenomena, the influence of comfort conditions in the surrounding areas and climate records. Lastly, regarding the use of the application DesignBuilder 1.2 in the present study, one may conclude that it is a good tool for computer simulations. However, it needs some adjustments to improve reliability in its use. There is a need for continued research, considering the dedication of users to the prototype, as well as the thermal charges of the equipment, in order to check sensitivity

Análise de métodos de predição de conforto térmico de habitação em clima quente-úmido com condicionamento passivo

The assessment of building thermal performance is often carried out using HVAC energy consumption data, when available, or thermal comfort variables measurements, for free-running buildings. Both types of data can be determined by monitoring or computer simulation. The assessment based on thermal comfort variables is the most complex because it depends on the determination of the thermal comfort zone. For these reasons, this master thesis explores methods of building thermal performance assessment using variables of thermal comfort simulated by DesignBuilder software. The main objective is to contribute to the development of methods to support architectural decisions during the design process, and energy and sustainable rating systems. The research method consists on selecting thermal comfort methods, modeling them in electronic sheets with output charts developed to optimize the analyses, which are used to assess the simulation results of low cost house configurations. The house models consist in a base case, which are already built, and changes in thermal transmittance, absorptance, and shading. The simulation results are assessed using each thermal comfort method, to identify the sensitivity of them. The final results show the limitations of the methods, the importance of a method that considers thermal radiance and wind speed, and the contribution of the chart proposed

Análise de componentes arquitetônicos para potencialização da ventilação natural com ênfase em captadores de vento

The building envelope is the principal mean of interaction between indoors and environment, with direct influence on thermal and energy performance of the building. By intervening in the envelope, with the proposal of specific architectural elements, it is possible to promote the use of passive strategies of conditioning, such as natural ventilation. The cross ventilation is recommended by the NBR 15220-3 as the bioclimatic main strategy for the hot and humid climate of Natal/RN, offering among other benefits, the thermal comfort of occupants. The analysis tools of natural ventilation, on the other hand, cover a variety of techniques, from the simplified calculation methods to computer fluid dynamics, whose limitations are discussed in several papers, but without detailing the problems encountered. In this sense, the present study aims to evaluate the potential of wind catchers, envelope elements used to increase natural ventilation in the building, through CFD simplified simulation. Moreover, it seeks to quantify the limitations encountered during the analysis. For this, the procedure adopted to evaluate the elements implementation and efficiency was the CFD simulation, abbreviation for Computer Fluid Dynamics, with the software DesignBuilder CFD. It was defined a base case, where wind catchers were added with various settings, to compare them with each other and appreciate the differences in flows and air speeds encountered. Initially there has been done sensitivity tests for familiarization with the software and observe simulation patterns, mapping the settings used and simulation time for each case simulated. The results show the limitations encountered during the simulation process, as well as an overview of the efficiency and potential of wind catchers, with the increase of ventilation with the use of catchers, differences in air flow patterns and significant increase in air speeds indoors, besides changes found due to different element geometries. It is considered that the software used can help designers during preliminary analysis in the early stages of design