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.
1 April 2020 in IOP Conference Series: Materials Science and Engineering
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.
Anthropogenic heat (QF) is one of the parameters that contributes to the urban heat island (UHI) phenomenon. Usually, this variable is studied holistically, among other anthropogenic flux such as industrial, vehicular, buildings, and human metabolism, due to the complexity of data collection through field measurements. The aim of this paper was to weigh vehicular anthropogenic heat and its impact on the thermal profile of an urban canyon. A total of 108 simulations were carried out, using the ANSYS Fluent® software, incorporating variables such as the number of vehicles, wind speed, urban canyon orientation, and urban canyon aspect ratio. The results were compared with a database of 61 American cities in 2015 and showed that orientation is the main factor of alteration in vehicular heat flow, increasing it in a range of 2 °C to 6.5 °C, followed by the wind speed (1.2 to 2.2 m/s), which allows for decreases of 1 to 3.8 °C. The exploration of these variables and their weighing in the definition of urban street canyon temperature profiles at the canopy level of urban structures provides valuable information on the hygrothermal comfort of its inhabitants; its appropriate quantification can be an example of many urban energy balances altering processes.
1 April 2020 in IOP Conference Series: Materials Science and Engineering
The city and its behavior in the transfer of heat, generates lines of research that study phenomena such as the Island of Urban Heat (ICU); Within its formation factors, the heat expelled by the vehicle is the least analyzed in the literature. Thanks to the Computational Fluid Dynamics (CFD) software and its validation with measurements in the field, data is acquired to examine the thermal behavior in an urban canyon based on the number of cars passing through it and the heat expelled by its engines, the speed of the wind and orientation. The results show that the temperature increases between 26% to 10% more, and the highest values are in the simulated cases with a north-south orientation, affecting the passer-by as to the energy efficiency of the buildings.