Escuela de Politécnica Superior

The Passive House (PH) concept is considered an e cient strategy to reduce energy consumption in the building sector, where most of the energy is used for heating and cooling applications. For this reason, energy e ciency measures are increasingly implemented in the residential sector, which is the main responsible for such a consumption. The need for professionals dealing with energy issues, and particularly for architects during the early stages of their architectural design, is crucial when considering energy e cient buildings. Therefore, architects involved in the design and construction stages have key roles in the process of enhancing energy e ciency in buildings. This research work explores the energy e ciency and optimized architectural design for residential buildings located in di erent climate zones in Spain, with an emphasis on Building Performance Simulation (BPS) as the key tool for architects and other professionals. According to a parametric analysis performed using Design Builder, the following optimal configurations are found for typical residential building projects: North-to-South orientation in all the five climate zones, a maximum shape factor of 0.48, external walls complying with the maximum U-value prescribed by Spanish Building Technical Code (0.35 Wm􀀀2K􀀀1) and a Window-to-Wall Ratio of no more than 20%. In terms of solar reflectance, it is found that the use of light colors is better in hotter climate zones A4, B4, and C4, whereas the best option is using darker colors in the colder climate zones D3 and E1. These measures help reaching the energy demand thresholds set by the Passivhaus Standard in all climate zones except for those located in climates C4, D3 and E1, for which further passive design measures are needed.

In this research work, energy simulation was used as a forecasting tool in architectural design. It includes the study of a multi-family residential building in five di erent climate zones of Spain, i.e., A4 (very hot climate zones), B4 (hot climate zones), C4 (moderate climate zones), D3 (cold climate zones), and E1 (very cold climate zones). The authors accomplished a sensitivity analysis in order to identify the influence of passive strategies (i.e., with regard to solar reflectance) and renewable energy (i.e., with regard to aerothermal energy) on indoor temperatures and energy demands. The increment in indoor temperatures depends on the neighboring buildings so that e ect of urban contexts as a source of protection against sunlight is also considered. The increment in the albedo (i.e., the solar reflectance) of the façade during the winter period produces little di erences in indoor operative temperatures. On the contrary, during the summer period, it produces large temperature di erences. Therefore, it is shown that colors significantly reduce temperatures from 1.24 to 3.04 C, which means considerable annual energy savings. This research demonstrates that solar reflectance can reduce the air indoor operative temperature down to 4.16 C during the month of May in the coldest climate zones. As a result of the simulations, it is noted that the coldest climate zones are influenced to a greater extent by the inclusion of their urban contexts in the simulations. However, the heating demand, without considering it, becomes lower. Therefore, ignoring the urban context produces important errors in the heating analysis (12.2% in the coldest climate zones) and also in the cooling analysis (39% in the hottest climate zones). Finally, the use of renewable energy in the configuration of a model with a high urban canyon (Hc), as well as with an east–west building orientation and a low albedo produces a di erence of around 76% in the cooling costs within the hottest climate zones and around 73% in the heating costs within the coldest climate zones. The results of this study can be applied as a guideline in early architectural design.

Concrete made with Portland cement is by far the most heavily used construction material in the world today. Its success stems from the fact that it is relatively inexpensive yet highly versatile and functional and is made from widely available raw materials. However, in many environments, concrete structures gradually deteriorate over time. Premature deterioration of concrete is a major problem worldwide. Moreover, cement production is energy-intensive and releases a lot of CO2; this is compounded by its ever-increasing demand, particularly in developing countries. As such, there is an urgent need to develop more durable concretes to reduce their environmental impact and improve sustainability. To avoid such environmental problems, researchers are always searching for lightweight structural materials that show high performance during both processing and application. Among the various candidates, Magnesia (MgO) seems to be the most promising material to attain this target. This paper presents a comprehensive review of the characteristics and developments of MgO-based composites and their applications in cementitious materials and energy-efficient buildings. This paper starts with the characterization of MgO in terms of environmental production processes, calcination temperatures, reactivity, and micro-physical properties. Relationships between different MgO composites and energy-efficient building designs were established. Then, the influence of MgO incorporation on the properties of cementitious materials and indoor environmental quality was summarized. Finally, the future research directions on this were discussed.

The extraction and use of construction materials generate an impact on the environment due to human activity. Facing these problems requires the development of new alternatives that support changes toward sustainable construction. The development of materials using natural resources creates an important opportunity to reduce the demand for energy, such as the energy used in manufacturing materials. This will contribute to the reduction of exhausting nonrenewable resources and waste production. The objective of this study is to develop a new kind of thermal insulation out of natural vegetation. In this case, using totora (Schoenoplectus californicus (C.A. Mey.) Sojak), which is an aquatic plant that grows in Lake Titicaca. Panels were made from both shredded and whole totora. These panels could be used to improve the thermal comfort inside houses in the high Andes region of Peru, where there are extreme variations in temperature. Studies have demonstrated that one of the characteristics of this plant is its low thermal conductivity, which reveals its potential for insulation. Considering which variables exist that affect the thermal efficiency of an insulating material, flexural tests, air permeability, water vapor permeability, and fire resistance tests were done.