No abstract

Energy consumption attributed to buildings amounts to approximately 30% globally. This consumption is even greater in buildings that lack climate adaptation strategies. In warm climates, solar control devices protect from thermal gains by direct solar radiation as a strategy to avoid overheating in buildings. Ventilated facades increase the energy efficiency of said devices when harnessing the convective cooling produced by the temperature and pressure differential inside the ventilated facade. The present research shows the thermal behaviour of an opaque ventilated facade through numerical modelling in ANSYS Fluent® computational fluid dynamics software in an extreme hot dry climate. The objective of the study was to analyze the effect of a ventilated facade on the thermal performance of the wall immediately adjacent to the living space as a passive convective cooling system. The variables analyzed were thickness of the air cavity, ambient temperature and wind speed of the external environment, as well as its effect on the surface temperature of the wall adjacent to the living space. The results show a decrease in the surface temperature of the wall, which reduces the total cooling load of the building.

This document describes the procedure to calculate the LST (Land Surface Temperature). The series of steps and equations is described using the thermal bands offered by the LandSat 8 satellite and the ArcGIS program tools. Although there are other methods and tools this procedure explicitly breaks down the use of information.

This study investigated an indirect evaporative cooling system (IECS) to control latent heat loss on roof ponds by increasing the evaporation rates on wet fabric membranes. The cooling potential of the proposed system was experimentally tested in a real environment and it was compared against a roof pond and a floating fiber (gunny bags) to provide an efficient model for buildings in hot and humid climates. Dry bulb temperatures (DBT) are presented for four experimental models. Solar irradiance, ambient and indoor dry bulb temperatures, and relative humidity (RH) were measured for seven days in each of the following climate conditions: hot sub-humid (mean DBT 27.3 °C and mean RH 72%), hot humid (mean DBT 27.1 °C and mean RH 81%), and warm sub-humid (mean DBT 25.2°C and mean RH 68%). There were no significant variations in thermal performance between the examined devices under hot humid conditions; however, the wet fabric device had superior thermal performance under sub-humid conditions when compared to the other IECSs. In the three climatic scenarios where the proposed system was tested, the wet fabric managed to reduce the indoor air temperature by 6.6 °C, 5.3 °C, and 5.1 °C, respectively, as compared to the outdoor air temperatures.

The development of real estate in Mexico has largely ruled out the comfort of users that focused on economic matters and made it difficult to make substantial progress in adopting measures to improve indoor environmental quality. Current research projects in Mexico found that roof construction in low-cost housing struggles to meet the requirements of the indoor climate. Passive cooling strategies are techniques to control heat gain and heat dissipation in buildings to maximise the comfort and health of building users while minimising energy use. Passive cooling systems recognize climate conditions and utilise renewable sources of energy such as the sun and wind to provide cooling and ventilation. Therefore, this study aims to develop a green and sustainable solution for existing concrete flat roofs with no major interventions and investments to save energy. The design of a passive device was tested to assess its effectiveness to protect flat roofs from shortwave radiation and to allow for heat dissipation in Mexican buildings. The study used a quantitative approach based on experiments and simulation tests to evaluate design efficiency. The results showed that a perforated device with an opening percentage of 88% and a cavity of 0.05m between the roof and the device provided effective protection. Also, the device with blinds of 45° showed lower operative temperatures within a range of mean values between 0.8°C and 0.9°C compared to a roof with a full shade cover in the hot and humid season. However, the perforated device with blinds of 90° in black colour delivered the best performance compared to other models and recorded a mean value of 1.13°C in the hot sub-humid season. The results revealed the efficiency of the proposed device that can be observed within different geometric configurations, surface properties as well as the use of the nocturnal radiative cooling potential in blocking solar radiation in Mexican buildings.