Annual Evaluation of Natural Ventilation Induction in Solar Chimneys under Tropical, Dry, and Temperate Climates of Mexico: A Case Study^†

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Comment

Authors Response / Description / Modifications

CA1

The manuscript lacks a clear and concise problem statement and research objectives. Readers should understand the study's purpose from the outset. Specifically, there exists quite a lot of studies in the literature with respect to the implementation of solar chimney in Mexican context. For example, citing the following article: https://doi.org/10.1016/j.buildenv.2022.108807 along with many others will help the authors to address the novelty of this article. 

We appreciate your time to review our paper. Thanks for your valuable observations. Section 1 was improved to describe the problem and objectives, the suggested reference, and three more were added. The main contribution of the article is the climatic additional variables in the balance energy model, e.g., atmospheric pressure and relative humidity changes, for accurate air density calculation.

CA2

The selection of the five cities in Mexico should be justified in terms of climatic representativeness. Were there specific criteria for their inclusion?

Thanks for your valuable observations. The five cities' selection was justified in the article to describe Mexico's main climatic conditions and their demographic impact on the country's energy consumption to satisfy ventilation and thermal comfort needs. García et al. (2004) and INEGI (2005) stated that 27.7% of Mexico's climatic regions are tropical,  49.1% are dry and semi-arid,  and 23.2% are humid and sub-humid temperate. Villahermosa and Merida are an exponent of tropical regions; in addition, the population of these cities is about 683,000 and 995,000 residents, respectively. Hermosillo and Monterrey are dry and semi-arid regions with 936,000 and 1,142,000 residents, respectively. Mexico City and Mexico Valley (Metropolitan area) are exponents of humid and sub-humid temperate regions with a population of about 21 800 000. 

CA3

The methodology section requires a more detailed and systematic explanation of the mathematical models used. The equations and assumptions should be thoroughly described.

Thanks for your valuable comments. A detailed description of equations was added, as assumptions for the solar chimney models were. Indeed, a pseudocode has been added to clarify the solution process of both solar chimney models.

CA4

The description of the experimental setup and data collection is somewhat vague. Readers need a clearer understanding of the data sources, collection process, and instrumentation.

Thanks for your valuable comments. A detailed description of the experimental setup and data collection is part of the experimental study reported by Torres-Aguilar et al. (2022). In this study, a brief explanation was included with some aspects of instrumentation and data acquisition. A detailed explanation was added to clarify the confusion.

CA5

The substantial differences in performance between SC-SoCh and TC-SoCh require a deeper and more critical analysis. What are the implications of these variations, and how can they be optimized?

Thanks for your valuable observation. A deeper explanation of the difference between both solar chimney performances was added in the discussion section. The performance variations are a consequence of the climatic conditions and the nonlinear behavior of the solar chimney performance. Although the variations in climatic conditions are an apparent factor in obtaining performance differences, the air-channel configurations induced a nonlinear thermal effect, which affected induced airflow (Torres-Aguilar et al., 2022). It was an expected result, which indicates the necessity to realize more parametric studies varying the parameters like the height, air gap, and materials to increase the SC-SoCh performance because, in most cases, this solar chimney configuration is a suitable option to be implemented in the facade of buildings.

CA6

The manuscript briefly mentions the impact of weather conditions on solar chimney performance but lacks a comprehensive discussion. Detailed insights into these weather-related effects are needed.

Thanks for your valuable comment. The discussion was extended about the weather-related effects.

CA7

The low thermal mass's impact on the operation time should be critically assessed. How does this relate to practical implementation challenges?

Thanks for your valuable observation. The low thermal mass of solar chimney performance is critical to increment the operation time; for that reason, some studies related to the use of massive materials to increase operation time, like phase change material, were cited (Tariq et al. (2022); Ke et al. (2021), Vargas-López et al. (2019)). However, the present study focussed on SC-SoCh and TC-SoCh performances for different climatic conditions, including the effect of moisture in the air and the atmospheric pressure on airflows induced. The presented results show that the operation time of solar chimneys corresponds to daylight operation, which is recommended for non-residential buildings.

CA8

The concept of air preconditioning is intriguing, but it needs to be more explicitly explained. How can it be implemented effectively to enhance solar chimney performa5hjjvb nce?

Thanks for your valuable observation. The concept of air preconditioning was referred to the thermal comfort needs because the evaluation of solar chimneys' performance under dry weather showed that inlet air temperature was higher than the ideal comfort temperature. We added this concept as a gap for a future study implementing the current proposed model with a building coupled to the SC-SoCh and TC-SoCh and analyzing different strategies to help thermal comfort. The present study focussed on the need to provide natural ventilation through passive ventilation systems like solar chimneys, and air preconditioning is out of the scope of the presented study.

CA9

The manuscript should discuss the practical implications of implementing these solar chimney systems in real-world applications. What are the challenges, limitations, and potential benefits?

Thanks for your valuable observation. Passive system technology in the real world is a challenge due to the paradigm in building design and the thermal comfort necessary in each case. A brief explanation about this point in the new manuscript version was added. However, this study exposes the capabilities of solar chimneys to provide natural ventilation in buildings under different climatic conditions as a substitute for mechanical fans and other electrical devices in practical implementations. Nevertheless, the construction cost and maintenance depend on the region and country. Also, passive ventilation systems are an alternative to reduce energy consumption and electrical bills. Likewise, their zero emission of pollutants is a valuable feature.

CA10

The presentation of results can be enhanced with more explicit comparisons and visual aids such as well-structured tables and figures. This will facilitate a clearer understanding of the data.

Thanks for your valuable observation. The main results values are described in the article. However, a manuscript revision was done to correct any mistakes and misunderstandings. For tables and figures, the page margin size limits Figure 5 to 9. Image qualities were improved, and it could zoom them and analyze results comparisons with more details. 

CA11

The "Future Work" section should include more specific examples of the research directions that could be pursued, and their expected contributions to the field.

Thanks for your comment. Detailed research directions for new contributions were added in the Future Work section.

CA12

A discussion on the potential environmental and energy savings impact of these findings should be included. How can solar chimney systems contribute to sustainability and energy efficiency?

Thanks for your valuable observation. The potential environmental and energy savings impacts are out of the scope of the presented study.

CA13

A more critical and comprehensive analysis of the limitations and uncertainties in the study should be provided. What are the potential sources of error, and how do they affect the results?

Thanks for your observation. The potential sources of error for the numerical study are the discretization and rounding errors. The roundoff error is reduced using double precision for all calculates, while the discretization error was attended using a suitable time step obtained by a temporal independence study of the SC-SoCh and TC-SoCh models. The potential sources of error were considered in the present study, and a description was added in the new version.

CA14

The language is clear and concise, but there are a few sentences that could be rephrased for better readability. For example, "The projection suggests that this increase in ventilation through active systems represents a 10% increase in total energy consumption for non-residential buildings" could be more straightforward.

Thanks for your observation. Many phrases were improved to describe in the best way the sentence contexts.

CA15

The statement that the "difference between the volumetric flow rate estimated through the SC-SoCh model and the experimental are acceptable" is somewhat vague. Readers may benefit from specific RMSD values or a comparison of the model's predictions to the experimental data.

Thanks for your comment. The explanation of the difference between numerical and experimental data during the validation process was improved.

CA16

The mention of air preconditioning in Monterrey and Hermosillo is intriguing. However, it would be beneficial to discuss what specific methods can be employed for air preconditioning and how they might mitigate the impact of high ambient temperatures.

Thanks for your comment. This work used the air preconditioning concept as a gap for a future study implementing the current proposed model with a building coupled to the SC-SoCh and TC-SoCh and analyzing different strategies to help thermal comfort. The air preconditioning analysis methodology is out of the scope of the presented study.

ID

Comment

Authors Response / Description / Modifications

CB1

Please indicate units and explanation of the values in Eqs. 3, 4, etc.

We appreciate your time to review our paper. Thanks for your observations. We have added an explicit description of the values used for the factor in the air channel and a nomenclature of the variable used in mathematical models.

CB2

Eqs.2, 3, etc: left part of equation means “resistance [m2K/W]”, but right part means “Energy storage [J]”. Please explain this situation or correct it.

Thanks for your comment. We consider the thermal resistance to the elements in the denominator; the reference does not involve the temperature difference and the cross-section area; the brace only considers system properties. The units of the left and right parts of equations are consistent.

CB3

Line 267: please, correct average convective heat transfer coefficient “10Wm2K−1”, into “10Wm­2K−1”.

Thanks for your observation. We have corrected the mistake in the new version.

CB4

Line 269: in empirical Eq. hconv−ext = 2.8 + 3.0Vwind. please indicate units for wind velocity.

Thanks for your comment. We have specified the units for the Vwind variable.

CB5

Line 303: In the expression A=1.2378847×10−5K −2 seven characters after the comma are redundant, please replace into A=1.2×10−5K −2 that is enough, because value A is too small (10−5). So do values B= -1.9×10−2K −1, C= 33.94, D=-6.3×10−3K (lines 304, 305) and α, β, γ in line 307.

Thanks for your observation. However, the coefficients for the empirical relations must not be modified because the mathematical relation is sensitive to this truncation error. The coefficients were cited according to the studies of Giancomo (1982) and Davis (1992).

CB6

The lines in Fig. 5a, 5c, 8a, 9a should be smooth, not broken lines, since the experimental data were obtained with a certain error.

Thanks for your comments. We have modified the mentioned figures for five cities.

CB7

Please describe the measuring equipment, its accuracy class and experimental error estimate.

Thanks for your comment. A detailed description of the experimental setup and data collection is part of the experimental study reported by Torres-Aguilar et al. (2022). In this study, a brief explanation was included with some aspects of instrumentation and data acquisition. A detailed explanation was added to clarify the confusion.

CB8

The conclusions need revision for being more effective. Please formulate the conclusions more succinctly, dividing them into numbered groups of short sentences.

Thanks for your observation. We have strengthened this section by being careful with the details of the contributions and findings of the study. 

CB9

Please replace the literature dated before 2018, (within the last 5 years).

Thanks for your observation. We have included more recent references.

ID

Comment

Authors Response / Description / Modifications

CC1

it is recommended to introduce a Nomenclature with the units, which will significantly increase the readability of the manuscript,

We appreciate your time to review our paper. Thanks for your observations. We have added a Nomenclature in the manuscript.

CC2

it is recommended to introduce a List of Abbreviations, which will also increase the readability of the manuscript,

Thanks for your observations. We have added a list of abbreviations in the manuscript.

CC3

Chapter 1. Introduction, contains the repeated text (lines 69 to 91), which is found in the chapter 4.Conclusions. Chapter 1 should be expanded with a broader review of the literature related to the analyzed research problem,

Thanks for your observations. We have corrected this repeated text. Also, we have made modifications to Chapter 1 according to your suggestion.

CC4

In some lines of the manuscript there are incorrect designations, e.g. line 270 (wind velocity [30]. E) etc.,

Thanks for your observations. We have corrected the incorrect designations in the manuscript.

CC5

Chapter 2.3. Parameters of study: weather conditions of Mexico and considerations for numerical modeling – please provide more information about the solver used to perform the calculations, details of the numerical simulation, etc.,

Thanks for your comments. We have included a deeper explanation of the weather conditions and details of parameters for numerical modeling and simulation. 

CC6

Chapter 4. Conclusion – it is necessary to distinguish between general conclusions and conclusions of a specific nature, i.e. quantitative, relating to the studied of the natural ventilation induction in solar chimneys.

Thanks for your observation. We have strengthened this section by being careful with the details of the contributions and findings of the study. 

ID

Comment

Authors Response / Description / Modifications

CA1

Some minor problems are to be improved

We appreciate your time to review our paper. Thanks for your valuable observations. Many phrases were improved to describe the article in the best way and corrected to improve the quality of the article.