Ricardo M.S.F. Almeida

Numerical analysis of the energy improvement of plastering mortars with phase change materials

Building components with incorporated phase change materials (PCMs) meant to increase heat storage capacity and enable stabilization of interior buildings surface temperatures, whereby influencing the thermal comfort sensation and the stabilization of the interior ambient temperatures. The potential of advanced simulation tools to evaluate and optimize the usage of PCM in the control of indoor temperature, allowing for an improvement in the comfort conditions and/or in the cooling energy demand, was explored. This paper presents a numerical and sensitivity analysis of the enthalpy and melting temperature effect on the inside building comfort sensation potential of the plastering PCM.

Energy and Water Consumption Variability in School Buildings: Review and Application of Clustering Techniques

AbstractIn developed countries, the building sector is responsible for a very significant share of the total energy consumption. School buildings, because they are places where children are educated and learn to become active members of the society, should be a good example of an efficient use of energy and water. In this study, data of the energy and water consumption of 23 Portuguese schools and their main building characteristics and properties were gathered. This information was normalized to homogenize the data set and then analyzed using advanced clustering techniques. The results show a significant variability in the consumption of different schools, even with similar characteristics, suggesting that the user behavior plays an important role in their efficiency. The complete linkage and Ward’s clustering methods were applied, both produced three clusters, and reference values for electricity and water consumption were defined.

Hygrothermal Performance and Degradation of Gypsum Houses in Different Brazilian Climates

This work consisted of two main lines of research: one of a literature review and other of simulation. In the first part, a modular constructive system based on gypsum blocks is presented. This constructive system reduces the manpower considerably, the time of execution and the final costs of construction. However, the durability assessment should be analysed but first its implementation and performance along the country must analysed.In this work a preliminary experimental characterization of the thermal conductivity, vapour permeability and water absorption coefficient of two different samples of gypsum plasters from the northeast Brazil (plaster pole of Araripe, Pernambuco) was performed. The experimental and analytical procedures followed either international standards or well-established methodologies, supporting the analysis of gypsum walls hygrothermal behaviour. The measured properties were adopted as inputs to hygrothermal simulation software and the analysis of gypsum based exterior walls was conducted for different climate zones and exposure conditions. The study demonstrates the durability issues that may arise in each location, due to differences in hygrothermal action.The other simulation part included hygrothermal advanced modelling, using the EnergyPlus software. The numerical results carried out allow a discussion over the interior comfort and durability of this modular constructive system. In this paper, the computer simulation model and the results of a parametric analysis of the dwelling performance on the eight climatic regions defined in Brazilian regulations are presented. The model was validated using the in situ measurements of air temperature.

Evaluating the Success of ERP Systems’ Implementation: A Study About Portugal

Information management has assumed an increasing importance at business organizations, over the last decades. Such trends lead companies to promote enormous efforts on organizing and optimizing their business processes, acquiring expensive enterprise information systems, aiming to promote an accurate answer to market uncertainty. Unfortunately, traditional software implementations have revealed low levels of satisfaction by Enterprise Resource Planning (ERP) systems’ customers. This study aims to evaluate the reasons for success and failure of ERP systems implemented at Portugal and the methodologies taken by consulting teams. To achieve such goal, it has been submitted a web survey to Portuguese companies and consulting teams, in order to confirm major errors, ERP systems’ coverage and quality’s response for business processes, and assessment of engineering requirements as a major concern. This study is concluded with the presentation of web survey results and some conclusions about ERP systems’ implementation at Portugal.

IRT Versus Moisture: In Situ Tests in Indoor Environment

This chapter describes a test campaign to evaluate the applicability of IRT to detect moisture in walls of buildings in use. The passive approach was implemented and moisture was detected due to the effect of evaporative cooling. Moisture in the walls under study had two different sources: rising damp and infiltration of rainwater. Rising damp was assessed in an exterior wall of a basement in a residential building, and infiltration of rainwater was evaluated in three locations, two exterior walls of a room in a residential building and in a wall of a classroom. The thermal images were compared with the results provided by a moisture detector.

IRT Versus Drying: In Situ Tests in Outdoor Environment

The applicability of IRT to assess the drying process of exterior walls after a long-term rainy period was evaluated through in situ tests. The physical phenomenon underlying these measurements was the effect of evaporative cooling, and the passive approach was implemented. Simultaneously, a moisture detector was also used to qualitatively assess the evolution of the moisture content of the walls. The walls under study were coated with similar rendering and painting, but they presented different exposure to solar and thermal radiation.

IRT Versus Moisture: Laboratory Tests

The applicability of IRT to assess moisture was evaluated in the laboratory using full-scale models. Two situations were evaluated: moisture intake due to rising damp and the drying process of a moist surface. In both cases, the passive approach was implemented as no external heat source was used. Moist areas were detected due to the effect of evaporative cooling at the surface. A wall made of limestone blocks was selected as a case study to assess rising damp. The specimen was partially immersed in water for about 3 weeks, and thermal images were taken before and during the absorption period. To assess the drying process of a moist surface, a typical brick wall covered with painted rendering was sprayed with water on a limited area and thermal images were taken during the drying period, which lasted about 10 days. For the two phenomena, besides thermal images, a moisture detector was also used to qualitatively evaluate the moisture content of the walls.

Measurement of Surface Temperature Using Different Devices

.There are several parameters that can influence significantly the measurement of surface temperatures using IRT. For that reason, this issue is deeply discussed in this chapter, including a comparison between the values obtained using three different devices (infrared camera, infrared thermometer and type T thermocouples). The chapter describes the methodology and the results attained in two experimental campaigns, one in situ and the other one in laboratory. In the in situ case study, the surface temperature of various finishing materials on the facades of a building was measured in different periods of the day and at different distances. The second campaign (laboratory) consisted in selecting materials with different emissivity and exposing them to external environmental conditions, while measuring their surface temperature.

Monte Carlo Simulation to Evaluate Mould Growth in Walls: The Effect of Insulation, Orientation, and Finishing Coating

Mould growth can have severe consequences both on the health of occupants and on constructions’ durability. Mould growth is a very complex process that depends on many factors such as temperature and relative humidity, presence of nutrients, and exposure time. Several mould prediction models, which allow estimating mould growth in building components and performing risk analysis, are available in the literature, such as the updated VTT model or the Biohygrothermal model. A Portuguese typical wall configuration was used for a sensitivity analysis. The importance of insulation (with and without insulation), orientation (north and south), and finishing coating (gypsum-based rendering, medium density fibreboard (mdf), and untreated wood) for the mould growth phenomenon was tested using both the updated VTT model and the Biohygrothermal model. A total of 12 case studies were investigated. The influence of indoor climate was evaluated by simulating 200 scenarios previously generated using the Monte Carlo method. Each of the scenarios has been applied to the 12 case studies, and 2400 hygrothermal simulations were carried out. Initially, the case studies were simulated using WUFI 1D since both mould growth models require the superficial temperature and relative humidity as input. Simulations were carried out for a one-year period. The updated VTT model produced results (mould index—M) ranging between 0.4 (gypsum-based rendering, insulated, and south oriented wall) and 5.9 (untreated wood, noninsulated, and north oriented wall) and the Biohygrothermal model (mould growth) between 10.1 and 406.4 mm for the same case studies. Despite that the effect of the orientation of the wall could be identified, the importance of insulation and nature of substrate was more evident. Although the two models produced overall comparable results, some differences could be found, creating the opportunity to discuss their strengths and weaknesses as well as their sensitivity to the input parameters.

Condensation and Mold Risk Evaluation in a Gymnasium: In Situ Measurements and Numerical Simulation

AbstractIn buildings, mold growth can have severe consequences on the occupants’ health and on the durability of the construction. Mold growth is a complex process that depends on many factors, suc...