A. Moret Rodrigues’s research while affiliated with Instituto Superior Técnico and other places

Self‐supporting concrete shell structures are highly efficient in distributing loads, which can result in very reduced thicknesses (ultra‐thin), giving them remarkable slenderness. Due to their geometric complexity, it is difficult to predict how they interact with wind action. The main aim of the present study is to assess the mean surface pressure coefficient distribution in a shell with a triangular plan shape and three supports for different angles of wind incidence. To determine the distribution of surface pressure coefficients and lift and drag force coefficients, an experimental study was carried out in a wind tunnel, and a numerical simulation study was performed through computational fluid dynamics. The experimental and numerical results were analyzed and compared, and making it possible to identify the most critical surface zones and wind incidences when the shell is under the wind action.

Electrochromic glazing alters its optical properties in the absence/presence of an electrical charge, varying from clear to dark to control daylighting and solar heat gains. This study aims to evaluate the impact of an electrochromic glazing, with indoor glare or temperature control, on the energy performance and thermal and visual comfort of an office room under three European climates, using a calibrated simulation model. The novelty of the paper lies in its combined performance assessment, using different standards and metrics. The results showed reduced climatization energy requirements with temperature control, but significantly increased artificial lighting energy use. Glare control achieved useful illuminance levels during 74–80% of working hours. Concerning temperature control, working hours within thermal comfort increased (21–43%) under a free-float regime. Moreover, the performance of this glazing was compared to that of a clear glazing with/without a reflective film and a thermochromic glazing for different solar orientations. The electrochromic glazing with glare control showed the highest energy savings (14–36%) for a western orientation, and the lowest negative impact on daylighting for a northern orientation. The best glare reduction was achieved with the reflective film. Considering the free-float regime, the electrochromic glazing, with temperature control, showed the highest increase in working hours within thermal comfort (6–9%) for a western orientation.

Fachadas de edifícios com grandes áreas envidraçadas tendem a promover trocas térmicas significativas que resultam em necessidades energéticas para climatização elevadas. Os envidraçados termocrómicos podem alterar de forma autónoma e reversível as suas propriedades térmicas e óticas dependendo da sua temperatura, promovendo a mitigação de ganhos térmicos e a melhoria de condições de conforto interior e eficiência energética. Este estudo tem como objetivo analisar o desempenho energético de um envidraçado termocrómico instalado num gabinete orientado a sudeste. Para esse fim, foi utilizado um modelo de simulação dinâmica, anteriormente calibrado com dados experimentais, para avaliar o desempenho energético anual do vidro termocrómico comparativamente ao de um envidraçado convencional incolor com e sem uma película refletora de controlo solar. As necessidades energéticas (aquecimento e arrefecimento) e o consumo energético (aquecimento, arrefecimento e iluminação artificial) foram obtidos para as diferentes soluções de envidraçados nas cidades de Bragança, Lisboa e Faro, representativas de diferentes zonas climáticas de Portugal. Com o envidraçado termocrómico obteve-se uma redução significativa, até 65%, das necessidades energéticas para arrefecimento. Apesar do comportamento dinâmico do envidraçado termocrómico e da diminuição das condições de iluminação natural do gabinete, foi possível obter uma redução do consumo anual energético total até 50%.

Glazings systems are responsible for significant building gains and losses regarding energy and thermal loads. Thus, current research has converged on finding glazing solutions that minimize heating, cooling, and lighting needs. One example of innovative glazing systems is thermochromic glazings. These glazings change their optical and thermal properties according to their surface temperatures by darkening at higher temperatures and consequently decreasing visible and solar transmittance. These property transitions have an impact not only on the heating and cooling needs of a building but also on the electric lighting needs. This research aims to study the impact that different switching temperature ranges and thermochromic coating transmittance values have on the energy use of an office room in different climates. This is accomplished with the annual energy simulation for heating, cooling, and electric lighting energy use of an office with a thermochromic glazing system in two different climates. A multi-objective optimization process is integrated to minimize the office’s thermal, lighting, and total energy use according to the thermochromic glazing transition temperatures and transmittances. Optimization results show highly conflicting values between the office room’s electric lighting and climatization energy use, showing that electric lighting energy use can increase up to 200% with low transition temperatures. Additionally, optimum solutions show improvements of 15% in total energy use against one off-the-market thermochromic glazing.

The trend and the market of thermal mortars increased in recent years in both new and thermal retrofitting of building facades mostly due to their enhanced thermal performance. These mortars are formulated using different lightweight aggregates, thus allowing a significant reduction of both density and thermal conductivity. However, this latter aspect should not compromise either durability or mechanical performance. It is therefore of paramount importance to have reliable data on the performance of these innovative mortars, thus contributing to increase their efficiency and durability. The aim of this paper is to evaluate the thermophysical and mechanical performance of three commercially available and five experimentally designed lightweight thermal insulating mortars with several aggregates (expanded polystyrene, expanded cork, expanded clay, and silica aerogel) replacing sand in different percentages. These thermal mortars were studied on their fresh and hardened states and when applied on brick substrate specimens and a prototype wall, also evaluating the influence of the substrate on the performance of thermal mortars. Results show that lightweight thermal insulating mortars exhibited lower density, mechanical properties and thermal conductivity and higher capillary water absorption when compared to the control mortar (100 % sand aggregate). Moreover, mortars applied on the prototype wall showed enhanced mechanical properties and slightly higher thermal conductivity than those applied on brick substrate specimens. Nevertheless, all mortars with insulating aggregates (either applied on the brick substrate or prototype wall) presented a thermal conductivity lower than 0.2 W/(m.K), thus following the requirements of the EN 998-1 for thermal mortars. Results contribute towards the development of innovative and sustainable thermal insulating mortars with improved effectiveness and durability.

What is and why study thermochromic glazing. Main aim and methodology of the simulation work conducted. Results (visual and thermal comfort) of the numerical simulation using optics, window, sketchup, energyplus and openstudio software. Conclusions and future studies.