articulos | Guillermo Barrios

2023

Viv. y Com. Sus.
Transferencia dinámica de calor en muros de block hueco en una vivienda con ventilación natural

José Manuel Torre, Irene Marincic Lovriha, Guadalupe Huelsz Lesbros, and 1 more author

Vivienda y Comunidades Sustentables, Jul 2023

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Este estudio presenta una investigación experimental sobre la transferencia dinámica de calor a través de un muro exterior de bloques huecos de concreto en una vivienda sin aire acondicionado en un clima cálido-seco. El estudio busca determinar si la parte sólida del bloque hueco, que se considera un puente térmico en este tipo de sistema constructivo, es o no el camino principal para la transferencia de calor en condiciones climáticas cálidas y secas. Los resultados muestran que la proporción entre el calor transferido por la trayectoria de la cavidad y el correspondiente a la trayctoria sólida varía a lo largo del día. Durante la noche, por la trayectoria dentro de la cavidad se transfiere casi el mismo calor que por la trayectoria de la parte sólida, y durante el di?a, por la trayectoria dentro de la cavidad se transfiere menos calor que por la trayectoria de la parte sólida, mientras que por lapsos cortos esta última proporción se invierte. Por lo tanto, se concluye que el camino sólido de un bloque hueco no puede considerarse automáticamente un puente térmico, ni el camino en la cavidad como la parte de baja transferencia de calor, debido a que esta proporción varía a lo largo del día. Este trabajo proporciona un análisis dinámico de la transferencia de calor a través de un material ampliamente utilizado en viviendas de bajos ingresos en México para una mejor comprensión del fenómeno.
@article{Ochoa2023, title = {Transferencia dinámica de calor en muros de block hueco en una vivienda con ventilación natural}, url = {https://revistavivienda.cuaad.udg.mx/index.php/rv/article/view/241}, doi = {10.32870/rvcs.v0i14.241}, number = {14}, journal = {Vivienda y Comunidades Sustentables}, author = {Ochoa de la Torre, José Manuel and Marincic Lovriha, Irene and Huelsz Lesbros, Guadalupe and Barrios, Guillermo}, year = {2023}, month = jul, pages = {109–122}, }

2022

Ing. Inv. y Tec.
Importance of taking into account the thermal mass in simulations for a non-air-conditioned house

Guadalupe Huelsz, Gabriela Alvarez, Jorge Rojas, and 1 more author

Ingenieria Investigacion y Tecnologia,, Jul 2022

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Building thermal simulation (BTS) programs are being increasingly used to evaluate the occupants’ thermal comfort and the building’s energy consumption. Although some authors have pointed out that not taking into account the thermal mass of the building’s components results in erroneous performance predictions, some BTS program users, standards and building rating systems still do not consider the thermal mass. The quantification of the difference in the simulations predictions of the performance of a building when its thermal mass is either considered (M) or ignored (NM) have been reported in the literature for air-conditioned buildings (AC). In this work, and for the first time, the quantification is made for a non-air-conditioned (nAC) building. The quantification of the difference between M and NM simulations’ results is also made for the same building but with AC. Simulations were carried out using EnergyPlus and considering four study cases according to the constructive systems of walls and roofs. The building is a house located in Monterrey, a Mexican city with a hot summer and a mild winter. For the nAC house the differences in monthly averages for the daily maximum and for the daily minimum temperatures between M and NM simulations are up to 8.3o C and 6.4o C respectively, and differences for the cold and hot discomfort degree hours are up to 124 %. For the AC house the differences between M and NM simulations on the cooling and heating thermal loads are up to 30 %. The difference in the air conditioning peak power demand is up to 38 %, and the difference in the time this peak occurs is up to 4 hours. These results show that differences between simulations are larger for the nAC house than they are for the AC house.
@article{huelsz2022, title = {Importance of taking into account the thermal mass in simulations for a non-air-conditioned house}, author = {Huelsz, Guadalupe and Alvarez, Gabriela and Rojas, Jorge and Barrios, Guillermo}, journal = {Ingenieria Investigacion y Tecnologia,}, volume = {23}, issue = {3}, pages = {1--15}, numpages = {15}, year = {2022}, publisher = {American Physical Society,}, doi = {10.22201/fi.25940732e.2022.23.3.024}, url = {https://www.revistaingenieria.unam.mx/numeros/2022/v23n3-08.pdf}, }
J. of Buil. Phys.
Didactic device for teaching the importance of the time-dependent model for heat transfer calculations in constructive systems of buildings

Guillermo Ramírez-Zúńiga, Guillermo Barrios, and Guadalupe Huelsz

Journal of Building Physics,, Jul 2022

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There is a worldwide effort aimed at reducing energy consumption in buildings. Part of this effort includes bioclimatic design in the curricula for architects and engineers. The selection of constructive systems for the building envelope according to the climate is of significant importance for bioclimatic design. This has to be done by calculating the heat transfer through the constructive system using the time-dependent model. However, because the time-dependent model is easier to use it is also more commonly employed. To contribute to the teaching of the importance of using the time-dependent model, a didactic device and a practice were proposed. This paper presents the physical problem and the heat transfer models; the didactic device’s design process, its components and operating method; as well as the methodology for the practice. The didactic device and practice were created by the interaction of experts and students who gave their opinions and suggestions during different workshops.
@article{ramirez2022, title = {Didactic device for teaching the importance of the time-dependent model for heat transfer calculations in constructive systems of buildings}, author = {Ram\'irez-Z\'u\'niga, Guillermo and Barrios, Guillermo and Huelsz, Guadalupe}, journal = {Journal of Building Physics,}, volume = {46}, issue = {2}, numpages = {10}, year = {2022}, publisher = {American Physical Society,}, doi = {10.1177/1744259122109305}, url = {https://doi.org/10.1177/1744259122109305}, }

2021

J. of Buil. Eng.
Validation of thermal simulations of a non air conditioned office building in different seasonal, occupancy and ventilation conditions

Ivette Calixto, Guadalupe Huelsz, Guillermo Barrios, and 1 more author

Journal of Building Engineering,, Jul 2021

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In this work, a methodology for the validation of non air conditioned building thermal simulations is proposed. Having certainty in these simulations can give confidence to building designers on the possibility to avoid the use of mechanical air conditioned systems or to reduce the period of their use, thus increasing the building’s energy efficiency. The main features of the proposed methodology that differentiate it from the previous ones are i) the separation of data inputs which values are known with uncertainty into those that have more influence on indoor air temperature and those with more impact on surface temperatures; ii) to carry out the calibration process in two stages having as comparison variables indoor air temperature in the first stage and adding surface temperatures in the second stage; and iii) to carry out the validation process in different seasonal, occupancy and ventilation conditions. The case study is an office building, simulations are performed in EnergyPlus employing the Airflow Network model for infiltration and ventilation. Quantitative comparisons are made using eight metrics. The results show the advantages of carrying out the second stage of validation proposed in this work. The validation results show that the building model obtained from the calibration process is suitable to simulate the building in different seasonal, occupancy and ventilation conditions, and can be used with certainty to test strategies to improve thermal comfort in the building. For the case study, two strategies are tested showing important reductions in thermal discomfort on occupancy hours during the critical hot season.
@article{calixto2021, title = {Validation of thermal simulations of a non air conditioned office building in different seasonal, occupancy and ventilation conditions}, author = {Calixto, Ivette and Huelsz, Guadalupe and Barrios, Guillermo and Cruz Salas, Miriam}, journal = {Journal of Building Engineering,}, volume = {44}, numpages = {10}, year = {2021}, publisher = {American Physical Society,}, doi = {10.1016/j.jobe.2021.102922}, url = {https://www.sciencedirect.com/science/article/abs/pii/S2352710221007804}, }
Energy Build
Evaluation of heat transfer models for hollow blocks in whole-building energy simulations

Guadalupe Huelsz, Guillermo Barrios, and Jorge Rojas

Energy and Building,, Jul 2021

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Five models to simulate time dependent heat transfer through constructive systems of building walls or roofs with internal air-cavities that are being implemented in whole-building energy simulation programs are evaluated by comparing their predictions with test measurements. The simulations are made using EnergyPlus. Comparisons of simulation and experimental results demonstrate that the equivalent homogeneous layer set (EHLS) model, presented here as Model 4, that considers the two dimensional heat transfer mechanisms of conduction through the solid part, natural convection in the air inside the cavities and radiation between aircavity surfaces, gives the best results. The second best results corresponds to Model 3 that considers all these heat transfer mechanisms but it is only one-dimensional (1D). The results of this model are close to that of Model 4, indicating that in this case of study the heat flows through the framing path and the in-cavity path are similar. The Model 2 that only considers conduction in 2D gives the third best results and the Model 1 that considers conduction but in 1D gives the worst results. Model 5 is generated from Model 3 but suppressing radiation, results indicate that for this case of study radiation has a significant contribution.
@article{huelsz2019, title = {Evaluation of heat transfer models for hollow blocks in whole-building energy simulations}, author = {Huelsz, Guadalupe and Barrios, Guillermo and Rojas, Jorge}, journal = {Energy and Building,}, volume = {202}, numpages = {10}, year = {2021}, publisher = {American Physical Society,}, doi = {10.1016/j.enbuild.2019.109338}, url = {https://doi.org/10.1016/j.enbuild.2019.109338}, }

2019

Eur. J. Mech. B
Heat transfer and flow transitions of a thermal plume generated by a heating element on the enclosure bottom wall

Guillermo Barrios, Guadalupe Huelsz, and Raúl Rechtman

European Journal of Mechanics - B/Fluids,, Jul 2019

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The two-dimensional buoyancy induced flow above a heating horizontal element in the center of the bottom of a rectangular enclosure filled with air is numerically studied using the thermal lattice Boltzmann equation method with two distribution functions. The heating element has a higher temperature than that of the remaining walls. The width and height of the enclosure are 5 and 10 times the length of the heating element respectively. The flow is space and time symmetric if after a transient, the flow is symmetric with respect to the vertical axis of the enclosure and is time independent. A suitable quantity, here called the asymmetry, is zero when the flow is time and space symmetric, positive and constant when the first symmetry is lost, and positive and time dependent when both symmetries are broken. Flow transitions are studied as the Rayleigh number, changes in a large interval. Eight flow transitions were found, the first ones related to the space and time symmetries. When both symmetries are broken, additional flow transitions were found by studying the Fourier power spectrum of the asymmetry, which allows the identification of the fundamental frequency and the appearance of harmonics and other frequencies. The average Nusselt number as a function of is also studied and a transition in their relationship is found at the appearance of harmonics, giving way to two different correlations.
@article{barrios2019, title = {Heat transfer and flow transitions of a thermal plume generated by a heating element on the enclosure bottom wall}, author = {Barrios, Guillermo and Huelsz, Guadalupe and Rechtman, Ra\'ul}, journal = {European Journal of Mechanics - B/Fluids,}, volume = {77}, numpages = {7}, year = {2019}, publisher = {American Physical Society,}, doi = {10.1016/j.euromechflu.2019.01.007}, url = {https://doi.org/10.1016/j.euromechflu.2019.01.007}, }