This paper reports the application of RC dynamic models for assessing thermal performance of buildings from in-situ tests (obtaining the U value for the walls, and the UA value and gA value for the whole buildings). The following aspects which are relevant to this approach have been systematically analyzed: The effect of the solar radiation on the heat flux through the opaque walls versus the performance of the models including this effect, the optimum number of nodes required to represent the thermal systems, the assignment of inputs and outputs and the length of the test period. Additionally, several options modelling relevant effects using unmeasured variables were studied to evaluate the feasibility to reduce the cost and intrusiveness of the measurement devices required to obtain accurate results. Data series recorded under different experimental conditions were considered to analyze the robustness and validity of the results. The performance of the models for each of these different test conditions is discussed. The uncertainties estimated using the described method for the U values of the opaque walls, and the UA and gA values of the whole building, are, respectively, 2.8%, 4.2% and 2.3%. The feasibility to model relevant effects using unmeasured variables has been demonstrated. A simplified and well-known building has been used as a case study, reinforcing and complementing the validation criteria.

This article presents an annual performance evaluation of single- and double-air-channel solar chimneys for natural ventilation induction under weather conditions in Mexico. The global energy balance method modeled both types of solar chimneys in an unsteady state. The case study evaluated five cities in Mexico. Experimental data of a single-air-channel chimney prototype evaluated under controlled conditions were used to validate the GEB numerical solution. Model validation considers climatic parameters to increase the accuracy of ventilation calculations, e.g., solar radiation, ambient temperature, wind speed, relative humidity, and atmospheric pressure. Experimental evaluation was performed considering the warmest and coldest days in each month of 2018. The modeling time to achieve the initial condition independence for each configuration was 72 h of the physical phenomenon. Results show that double-air-channel solar chimney tested configurations induced at least 70% more airflow than single-air-channel solar chimneys. Both solar chimney airflows were higher than the dwelling-unit ventilation for a space of 54 m${}^3$, and volumetric flows up to 120 m${}^3$h${}^{-1}$ were identified for two studied cities.

In this article, a theoretical–experimental study was conducted on a two-channel solar air collector (SAC-2C). For the experimental study, a prototype of the SAC-2C was designed, built, and instrumented with dimensions of 1.860 m in length, 0.605 m in width, and featuring two air channels of 5.5 mm and 5 mm thick each, respectively. The collector operates via forced convection and was positioned at an inclination angle of 18.88 deg at the Tecnológico Nacional de México CENIDET campus (TecNM/CENIDET) located in Cuernavaca, Morelos, Mexico. For the theoretical analysis, the method of global energy balances in two dimensions (2D) and under transient conditions was applied. Temperature differences of up to 3.0∘C are observed with respect to mathematical models that do not consider heat conduction terms in solid elements. These differences are accentuated in the glass cover. Furthermore, altitude’s impact on air density calculations could influence theoretical temperature profiles up to 3.0∘C. The theoretical results of the numerical model were validated with the information obtained from the experimental tests, which showed good similarity. It was observed that the elements of SAC-2C are sensitive to sudden changes in meteorological conditions. The system’s response time is not only associated with the characteristics of the materials but also with the thermal bridges between the absorber plate and the casing. The calculation of the appropriate heat transfer coefficients allowed the evaluation of energy gains or losses in the SAC-2C collector.

In this paper, a numerical heat transfer study of a solar air collector with two channels (SAC-2C) was carried out. Energy global balances in two dimensions (2D) and unsteady state were considered, as well as bio-climatic conditions of Toluca city in Mexico (sub-humid temperate climate). Six mass flow rates (0.01, 0.05, 0.1, 0.2, 0.4, 0.5 kg/s) were considered during the numerical simulation, for the coldest and the warmest day of each month during a complete year (2019). Among the results, it was found that thermal efficiency of the system increases up 35% when the mass flow rate change from 0.01 to 0.2 kg/s, meanwhile the maximum efficiency of 84% were obtained, for a mass flow rate of 0.5 kg/s. Finally, based on a cost-benefit analysis, it was determined that the SAC-2C has a recovery time of the initial investment ($ 250 USD) of 3 and a half years. So that, the SAC-2C has the capacity to produce 1,654,451 kWh/m² of clean energy annually, which is equivalent to ceasing to produce 871,895 kg CO₂ per square meter of installation.

This article presents a methodology for a validated multi-city parametric dataset for data-driven assessment of single-channel solar chimneys as energy-efficient components of smart-city buildings. The dataset covers Mexico City, Hermosillo, Mérida, Monterrey, Toluca, and Villahermosa across tropical, dry, and temperate Köppen–García climates. The proposed dataset combines nine absorber-wall materials, four cardinal orientations, and 24 representative days (the warmest and coldest day of each of the twelve calendar months), generating 5184 CSV files ($6\times 24\times 4\times 9=5184$). A transient global energy balance model calculates heat conduction, natural convection, radiative exchange, and buoyancy-driven ventilation under real climatic conditions included in the dataset. The GEB model is experimentally validated against an aluminum-absorber prototype. The energy balance model discretizes massive and phase-change absorber walls into 21 layers and represents latent thermal storage through an effective specific heat formulation. Consequently, the ∼133.64 GB dataset records time-dependent temperatures, airflow rates, air changes per hour, instantaneous efficiency, and layer-resolved liquid fractions. A proposed open Python 3.12.7 toolkit also organizes the heterogeneous file hierarchy and enables reproducible, scalable retrieval of specific configurations. The resource supports big-data analytics, surrogate modeling, machine-learning training, predictive performance assessment, and data-driven decision-making for passive ventilation. Furthermore, the dataset supports future integration with IoT-based building monitoring systems for model calibration, operational prediction, and automated energy management. Overall, the proposed resource advances scalable, climate-responsive solutions for resilient, energy-efficient, and sustainable smart cities.

En este artículo se presentan los resultados experimentales de la extracción de aceites esenciales mediante la técnica de destilación por arrastre de vapor, utilizando materiales vegetales como eucalipto, romero y salvia. Se registraron datos de temperatura y el tiempo de goteo. La metodología incluyó un modelo matemático para describir la transferencia de aceite durante la destilación. Además, se propuso un observador de estados para estimar variables como la masa de aceite esencial en el interior del destilador. Los datos recabados en los experimentos mostraron que la temperatura es una variable importante para la etapa de condensación y que debería ser controlada. Por ello, el desarrollo de algoritmos de control como los observadores de estado, resulta fundamental para mejorar la supervisión del proceso, detectar fallas en tiempo real, favorecer la operación y reducir el consumo energético.