Review of Heliodon Developments and Computational Tools for Building Shadow Analysis

Round 1

Reviewer 1 Report

Thank you very much for a very interesting and well-realized review.

In general, the document is quite good, but before accepting the article for publication, I would recommend the authors to consider some of my comments about this work:

1. I would recommend expanding the introduction, since there is no clear argument for the importance of your work, what problem or problems your research helps to solve, and it is also necessary to note which readers your work will be useful.

2. Therefore, due to the weak motivation for the need for your research, a weak abstract followed, which also needs to be rewritten. Usually the structure of abstracts includes these main parts: Introduction, Research significance, Methodology, Principal results and Conclusion.

3. In paragraph 2.4 -  I would recommend to add a discussion about the temporal evolution of heliodon types and their structures

4. In Table 3 - I would recommend adding the date of consultation on license prices

 

Author Response

Dear Reviewer

Thank you very much for your important observations. Your comments have been very helpful to us to improve our writing and we are aware of all your points.

1. I would recommend expanding the introduction, since there is no clear argument for the importance of your work, what problem or problems your research helps to solve, and it is also necessary to note which readers your work will be useful.

The introduction was expanded from line 49 to line 90, as:

“The methodology to analyze the sunlight/shading on a building consists of locating in the tool, either the heliodon or the software, the geographical position with the latitude and longitude of the terrain site and observing the shadow projected on the model, for the case of a heliodon, it will be a scale model of the building under study and, in the case of software, the building is created as a digital model. Subsequently, the focus or viewfinder is positioned on the day and time desired by importance, such as the time when the highest temperature is recorded or the longest day, or some specific date. The position of the shadow is observed on the model, and it is identified if it is favorable or not, according to the design requirements that prevail in the climate of the site.

The analysis of shading or sunlight in the architectural project stage represents an excellent strategy to reduce electricity consumption [8] and guarantee the user's thermal comfort [9,10], while the light comfort is reviewed [11,12]; because it depends on the orientation, the envelope of the building and the relationship between the solid wall and the transparent wall or opening, to identify the energy balance by Direct Solar Gain, as well as the energy load requirements for air conditioning [13].

At the urban level, the analysis of shading with heliodon or computational tools allows the design of strategies to increase pedestrian areas that cause outdoor activities between the open spaces of buildings and guarantee thermal comfort as in the esplanades, as well as finding the differences between winter and summer [14-16]. In addition, the shading analysis identifies the possible error of overestimating the cooling or heating loads [17], which would result in unnecessary energy consumption for the air conditioning of buildings. And on the other hand, the light impact or the use of daylight inside living spaces can also be estimated without increasing the thermal load by radiation [18]

The tools for shading analysis allow the effect of direct solar incidence on buildings to be evaluated and verify, during the architectural project stage, the possible impact on the cost of air conditioning, thermal comfort, and even aspects of natural lighting [19,20]. They also allow the proper design of the shading elements themselves such as eaves, sunshades, and recesses of the openings or windows of a building so that there is a balance between Direct Solar Gain (SGD) and light comfort to avoid glare or shadows, especially in desert or high radiation areas.

The importance of this work lies in the fact that the study of the incident radiation on a building in warm climatic zones such as Mexico, which is translated into direct solar gain that increases the temperature and the cooling load requirement, causing greater electrical consumption [21]. Knowledge of the tools for shading analysis is of interest to building designers, constructors, and consultants on issues of energy efficiency, energy-saving, sustainability, and bioclimatic architecture so that the building is energy efficient and complies with evaluation methodologies such as LEED, BREE, or the Official Mexican Standards (008 and 020 ENER) in Mexico.

Likewise, in the teaching-learning processes of the Architecture and Design career, even on an urban scale, it is of interest to planners and urban planners [22,23]. Likewise, for designers of photovoltaic systems, sunlight analysis allows them to identify the best location for these technologies for optimal performance [24,25].”

2. Therefore, due to the weak motivation for the need for your research, a weak abstract followed, which also needs to be rewritten. Usually the structure of abstracts includes these main parts: Introduction, Research significance, Methodology, Principal results and Conclusion.

The abstract was modified as follows

“In the last decade, the analysis of shading or sunlight in architectural projects has become an important role in improving building thermal and lighting performances. Selecting an appropriate software tool for this type of analysis is a challenging task for the little information available. Therefore, the paper reviews the existing literature on heliodons design and computational tools for building shadow analysis. The review includes a detailed description and classification of various types of heliodons, along with their operating principles and geometric features that affect their performance, including light sources, positioning mechanisms, and structures. This paper also includes descriptions and classification of the computational tools for testing building shadow patterns and applications in architecture. Moreover, this paper shows the capabilities of different software packages and their essential features, strengths, and limitations. In addition, we identified the current gaps in the literature on heliodons and computational tools. According to the results, for the case of heliodons, there is a lack of error analysis and a standardized calibration process, therefore, repeatability of the results is difficult to achieve. In the case of computational tools, they have reached a degree of success in the market than the heliodons, however, the cost of licensing and learning curve can be a limitation.”

3. In paragraph 2.4 -  I would recommend to add a discussion about the temporal evolution of heliodon types and their structures

It was added a paragraph of the evolution of heliodons from line 370 to line 375, and a new image of historic evolution (Fig. 12)

Fig. 12 shows the historic evolution of heliodon per year within the period 1932 to 2017. As can be seen the design of heliodons was gradually incremented from 1932 to 2007, due to the growing interest in the scientific community in the use of this device. However, from 2007 to 2011 was not reported any heliodon design. It could be due to the development and the use of computational tools. It is important to note that from 2011 to 2017 again there was an interest in the use of the heliodon

Figure 12. Historic evolution of heliodon

4. In Table 3 - I would recommend adding the date of consultation on license prices

Table 3 adds the date of consultation in the foot

“Price in dollars *1€=US1.11, **1£=US1.30, ***1MX=US0.050 (consulted on 12nd April 2022)”

 

 

 

Author Response File: Author Response.pdf

Reviewer 2 Report

I found the study interesting. A review of computational tools and techniques for heliodon design is presented in this paper. Shade analysis was the focus of this paper, but the author failed to provide any details as to why this method was chosen over others. Additionally, for each tool's explanation, the authors should also emphasize how each tool can be used for shading analysis and how it performs for shading. Providing this analysis in this paper would make it easier for the reader to follow and understand the rest of the paper. Please read the following brief details:

 

Point 1: The author should provide more explanation about why shading analysis was chosen. In most cases, daylight and glare analysis using DA is more important than shading in order to reduce energy consumption. This analysis would add more value to this manuscript if it were included in this review. 

Point 2: In addition, for the explanation of each tool, the authors should also emphasize how it can be applied to shading analysis and how it works with shading.

Point 3: If the author focuses on shading, then the author should provide more information about methodology analysis for each tool (heliodons and computational tools). Describe how it analyzes shadow in detail. What validation does each tool provide? What results does each tool provide?

Point 4: There is another concern regarding the review paper. In reference, there are fewer articles relating to current issues. There are mostly articles from 2012, 2014, and 2008. Would you be able to tell me if these methods are still being used today, or if there are newer methods to analyze shading? Authors should complete these manuscripts with newest published  journals (2020-2022). This Information will give readers updated information about specific devices.

Point 5: In addition, shading is highly dependent on the design of the building. For these to be more useful, it would be useful to give more details about how these tools work and shading analysis. How to set? And compare shading results between those heliodons and software tools.

Author Response

Dear Reviewer

Thank you very much for your important observations. Your comments have been very helpful to us to improve our writing and we are aware of all your points.

Point 1: The author should provide more explanation about why shading analysis was chosen. In most cases, daylight and glare analysis using DA is more important than shading in order to reduce energy consumption. This analysis would add more value to this manuscript if it were included in this review.

This point was added in the introduction from line 49 to line 90

“The methodology to analyze the sunlight/shading on a building consists of locating in the tool, either the heliodon or the software, the geographical position with the latitude and longitude of the terrain site and observing the shadow projected on the model, for the case of a heliodon, it will be a scale model of the building under study and, in the case of software, the building is created as a digital model. Subsequently, the focus or viewfinder is positioned on the day and time desired by importance such as the time when the highest temperature is recorded or the longest day or some specific date. The position of the shadow is observed on the model and it is identified if it is favorable or not, according to the design requirements that prevail in the climate of the site.

The analysis of shading or sunlight in the architectural project stage represents an excellent strategy to reduce electricity consumption [8] and guarantee the user's thermal comfort [9,10], while light comfort is reviewed [11,12], because it depends on the orientation, the envelope of the building and the relationship between the solid wall and the transparent wall or opening, to identify the energy balance by Direct Solar Gain, as well as the energy load requirements for air conditioning [13].

At the urban level, the analysis of shading with heliodon or computational tools allow the design of strategies to increase pedestrian areas that cause outdoor activities between the open spaces of buildings and guarantee thermal comfort as in the esplanades, as well as finding the differences between winter and summer [14-16]. In addition, the shading analysis identifies the possible error of overestimating the cooling or heating loads [17], which would result in unnecessary energy consumption for air conditioning of buildings. And on the other hand, the light impact or the use of daylight inside living spaces can also be estimated without increasing the thermal load by radiation [18]

The tools for shading analysis allow the effect of direct solar incidence on buildings to be evaluated and to verify, during the architectural project stage, the possible effect on the cost of air conditioning, thermal comfort and even aspects of natural lighting [19,20]. They also allow the proper design of the shading elements themselves such as eaves, sunshades and recesses of the openings or windows of a building so that there is a balance between Direct Solar Gain (SGD) and light comfort to avoid glare or shadows, especially in desert or high radiation areas.

The importance of this work lies in the fact that the study of the incident radiation on a building in warm climatic zones such as Mexico, which is translated into direct solar gain that increases the temperature and the cooling load requirement, causing greater electrical consumption [21]. Knowledge of the tools for shading analysis is of interest to building designers, constructors, and consultants on issues of energy efficiency, energy-saving, sustainability, and bioclimatic architecture so that the building is energy efficient and complies with evaluation methodologies such as LEED, BREE, or the Official Mexican Standards (008 and 020 ENER) in Mexico.

Likewise, in the teaching-learning processes of the Architecture and Design career, even on an urban scale, it is of interest to planners and urban planners [22,23]. Likewise, for designers of photovoltaic systems, sunlight analysis allows them to identify the best location for these technologies for optimal performance [24,25].”

 

Point 2: In addition, for the explanation of each tool, the authors should also emphasize how it can be applied to shading analysis and how it works with shading.

This point was addressed as follow

From line 432 to 340

In [24], the concept of a solar PV cell in phyllotaxy pattern is modeled in Amethyst Shadow FX. The authors simulated the sunray at a different angle analyzing the intersection of the shadow between the PV cells. The results showed energy loss for shadow and maximum energy of the device. Sil [65] studied the effect of shadow on neighborhood structures from a proposed high rise building in Mumbai, India. The author made a comparison of shadows without the high rise and with the construction in different seasons. The results showed that neighbor structures are responsible for interrupting direct sunlight, however, they receive sufficient sunlight in a day. Therefore, it is no observed much difference with the proposed building in terms of shadow.

From line 466 to 371

This software has been used in [69], where the authors studied of solar access in Bogotá, Colombia, according to Knowles' concept of the solar envelope. The projections of shadow were made in different months of years. According to the results, the case study has a negative energetic impact on the surrounding urban fabric. The shadow projected prevented the passive solar gains required by the neighboring buildings during the cold days, affecting the social dynamics, comfort, and health of the inhabitants.

From line 510 to 512

This tool has been used as an educational tool learning geometry about distance and angle in space and to promote creativity in education through the three-dimensional design [22,23].

From line 532 to 540

An example of the use of this tool is the work carried out by [64]. The authors calculated the shading, sunlit and shading-sunlit indexes in buildings in hot dry climates such as Iran. To determine the relation of calculated indexes and geometrical parameters and aspect ratios of the courtyards, several statistical analyses were conducted. The authors suggested a new layout to optimize its climate adaptability for the whole year, due to the climate adaptability of courtyards was 51% and 20% for summer period and for the winter, respectively. In [79], the author focused on the thermal and lighting analysis of two standard office models. Changing the orientation of the room, angle of the blinds, and material of the floor and walls could achieve an optimum design.

From line 561 to 567

An example of this tool was used by Pawar and Kanade [8], who evaluated the energy efficiency of building with respect to the Energy Conservation Building Code (ECBC). According to results, the authors obtained the best orientation of building. In [88], investigated the energy efficiency of a bookstore in Cairo, Egypt. The simulation results were compared with the field’s experimental measurements, which revealed a difference of 4°C between them. The manuscript gave proposals to provide more accurate data in simulating hot arid climates.  

From line 578 to 582

This tool was used by [93], where the authors evaluated the daylighting performance in a student residential building with internal partition. The results reveal that partitions provide privacy and a sense of enclosure, but they block more sunlight. Therefore, it is suggested a perpendicular position for the internal partition to the window for more daylight penetration inside the room.

From line 592 to 604

It can be seen in [19], where the authors examined the influence of different window to external wall proportions with different window opening percentages for offering thermal comfort. Aram et al. [10] analyzed the thermal comfort and building energy performance of a single-story office building with a corner atrium type. Its study used different orientations and window opening ratios and was based on the ASHRAE 55, 2013–ISO 7730: 2005 and EN 15251: 2007 standards. The results reveled that the northeast atrium orientation in the office obtained a sufficient energy performance and suitable thermal comfort for users throughout the year. Kwon et al. [97] studied the balance indoor energy demands and outdoor thermal comfort of a flexible canopy. Several software packages such as Ecotect, Rayman, WinAir, DaySim, and EDSL TAS were used to determine the environmental influence of the canopy in different orientations and locations. The results showed a reduction in energy demands (heating and electricity for lighting) with the use of this canopy and an increase in outdoor thermal comfort under the canopy area.

From 617 to 620

In [100], the authors assessed the thermal performance of an opaque ventilated façade in the summer period using ESP-r software. The simulation model was calibrated with experimental measurements. The results showed ~7% of difference between predicted and measured results.

From line 630 to 640

Awada and Abd-Rabob [103] used Revit's shading analysis module to evaluate different scenarios to predict optimal energy performance and daylighting strategies based on climatic conditions and design demands, especially in their shading strategies. The authors concluded that the daylight performance, solar radiation, glare problems and thermal/visual comfort issues can be improvement with this software. Al Douryet al. [104] examined the thermal performance of an Ozyegin University building. The building position, orientation, and detail of walls, roof, floor, windows, and curtain walls were key parameter in the analysis. It was reported that the peak load for both cooling and heating achieve 1.3 and 0.4 MWh, respectively. The manuscript provided some options for improvement the building performance such as replacing a double glass window by triple glass leads to reducing the annular energy demand and its cost around 6%.

 

Point 3: If the author focuses on shading, then the author should provide more information about methodology analysis for each tool (heliodons and computational tools). Describe how it analyzes shadow in detail. What validation does each tool provide? What results does each tool provide?

This point was addressed in a general way. For example, It was added the methodology from line 49 to 57

“The methodology to analyze the sunlight/shading on a building consists of locating in the tool, either the heliodon or the software, the geographical position with the latitude and longitude of the terrain site and observing the shadow projected on the model, for the case of a heliodon, it will be a scale model of the building under study and, in the case of software, the building is created as a digital model. Subsequently, the focus or viewfinder is positioned on the day and time desired by importance such as the time when the highest temperature is recorded or the longest day or some specific date. The position of the shadow is observed on the model and it is identified if it is favorable or not, according to the design requirements that prevail in the climate of the site.”

And it was added in the following paragraphs.

From line 433 to 341

In [24], the concept of a solar PV cell in phyllotaxy pattern is modelled in Amethyst Shadow FX. The authors simulated the sunray at a different angle analyzing the intersection of the shadow between the PV cells. The results showed energy loss for shadow and maximum energy of the device. Sil [65] studied the effect of shadow on neighborhood structures from a proposed high rise building in Mumbai, India. The author made a comparison of shadows without the high rise and with the construction in different seasons. The results showed that neighbor structures are responsible for interrupting direct sunlight, however, they receive sufficient sunlight in a day. Therefore, it is no observed much difference with the proposed building in terms of shadow.

From line 467 to 372

This software has been used in [69], where the authors studied of solar access in Bogotá, Colombia, according to Knowles' concept of the solar envelope. The projections of shadow were made in different months of years. According to the results, the case study has a negative energetic impact on the surrounding urban fabric. The shadow projected prevented the passive solar gains required by the neighboring buildings during the cold days, affecting the social dynamics, comfort, and health of the inhabitants.

From line 510 to 512

This tool has been used as an educational tool learning geometry about distance and angle in space and to promote creativity in education through the three-dimensional design [22,23].

From line 533 to 541

An example of the use of this tool is the work carried out by [64]. The authors calculated the shading, sunlit and shading-sunlit indexes in buildings in hot dry climates such as Iran. To determine the relation of calculated indexes and geometrical parameters and aspect ratios of the courtyards, several statistical analyses were conducted. The authors suggested a new layout to optimize its climate adaptability for the whole year, due to the climate adaptability of courtyards was 51% and 20% for summer period and for the winter, respectively. In [79], the author focused on the thermal and lighting analysis of two standard office models. Changing the orientation of the room, angle of the blinds, and material of the floor and walls could achieve an optimum design.

From line 562 to 568

An example of this tool was used by Pawar and Kanade [8], who evaluated the energy efficiency of building with respect to the Energy Conservation Building Code (ECBC). According to results, the authors obtained the best orientation of building. In [88], investigated the energy efficiency of a bookstore in Cairo, Egypt. The simulation results were compared with the field’s experimental measurements, which revealed a difference of 4°C between them. The manuscript gave proposals to provide more accurate data in simulating hot arid climates.  

From line 579 to 583

This tool was used by [93], where the authors evaluated the daylighting performance in a student residential building with internal partition. The results reveal that partitions provide privacy and a sense of enclosure, but they block more sunlight. Therefore, it is suggested a perpendicular position for the internal partition to the window for more daylight penetration inside the room.

From line 593 to 605

It can be seen in [19], where the authors examined the influence of different window to external wall proportions with different window opening percentages for offering thermal comfort. Aram et al. [10] analyzed the thermal comfort and building energy performance of a single-story office building with a corner atrium type. Its study used different orientations and window opening ratios and was based on the ASHRAE 55, 2013–ISO 7730: 2005 and EN 15251: 2007 standards. The results reveled that the northeast atrium orientation in the office obtained a sufficient energy performance and suitable thermal comfort for users throughout the year. Kwon et al. [97] studied the balance indoor energy demands and outdoor thermal comfort of a flexible canopy. Several software packages such as Ecotect, Rayman, WinAir, DaySim, and EDSL TAS were used to determine the environmental influence of the canopy in different orientations and locations. The results showed a reduction in energy demands (heating and electricity for lighting) with the use of this canopy and an increase in outdoor thermal comfort under the canopy area.

From 618 to 621

In [100], the authors assessed the thermal performance of an opaque ventilated façade in the summer period using ESP-r software. The simulation model was calibrated with experimental measurements. The results showed ~7% of difference between predicted and measured results.

From line 631 to 641

Awada and Abd-Rabob [103] used Revit's shading analysis module to evaluate different scenarios to predict optimal energy performance and daylighting strategies based on climatic conditions and design demands, especially in their shading strategies. The authors concluded that the daylight performance, solar radiation, glare problems and thermal/visual comfort issues can be improvement with this software. Al Douryet al. [104] examined the thermal performance of an Ozyegin University building. The building position, orientation, and detail of walls, roof, floor, windows, and curtain walls were key parameter in the analysis. It was reported that the peak load for both cooling and heating achieve 1.3 and 0.4 MWh, respectively. The manuscript provided some options for improvement the building performance such as replacing a double glass window by triple glass leads to reducing the annular energy demand and its cost around 6%.

 

Point 4: There is another concern regarding the review paper. In reference, there are fewer articles relating to current issues. There are mostly articles from 2012, 2014, and 2008. Would you be able to tell me if these methods are still being used today, or if there are newer methods to analyze shading? Authors should complete these manuscripts with newest published  journals (2020-2022). This Information will give readers updated information about specific devices.

It was added the following literature

1. Pawar, Bhagyesh S., and G. N. Kanade. Energy optimization of building using design builder software. International Journal of New Technology and Research2018, 1, 263152.
2. Esabegloo, A., M. Haghshenas, and A. Borzoui. Comparing the results of thermal simulation of rasoulian house in Yazd by design builder software, with experimental data.Iran University of Science & Technology, 2016, 2, 121-130.
3. Aram, Reihaneh, and Halil Zafer Alibaba. Thermal comfort and energy performance of atrium in Mediterranean climate. Sustainability, 2019, 4, 1213. Doi: 10.3390/su11041213
4. Valladares-Rendón, L. G., Gerd Schmid, and Shang-Lien Lo. Review on energy savings by solar control techniques and optimal building orientation for the strategic placement of façade shading systems. Energy and Buildings,2017, 140, 458-479. Doi: 10.1016/j.enbuild.2016.12.073
5. Moussa, Rania R., and Dina Rushdy M. Moawad. Investigating the Efficiency of Building Energy Simulation Software on Architectural Design Process. Proceedings of the 2020 9th International Conference on Software and Information Engineering (ICSIE). 2020.
6. Sokkar, Refaa, and Halil Z. Alibaba. Thermal comfort improvement for atrium building with double-skin skylight in the mediterranean climate. Sustainability, 2020, 6, 2253. Doi: 10.3390/su12062253
7. Bournas, Iason, et al. Energy renovation of an office building using a holistic design approach.  Build. Eng. 2016, 7, 194-206.
8. Al-Masrani, Salwa M., and Karam M. Al-Obaidi. Dynamic shading systems: A review of design parameters, platforms and evaluation strategies.  Constr. 2019, 102, 195-216.
9. Peng, Fen, Ying Xiong, and Bin Zou. Identifying the optimal travel path based on shading effect at pedestrian level in cool and hot climates. Urban Climate2021, 40, 100988.
10. Liu, Haijing, et al. Evaluating the impact of shading from surrounding buildings on heating/cooling energy demands of different community forms. Building and Environment, 2021, 206, 108322. Doi: 1016/j.buildenv.2021.108322
11. Aguilar, Alexis, et al. Solar radiation and architectural design in Barcelona. Proc. of PLEA. 2011.
12. Aram, Reihaneh, and Halil Zafer Alibaba. Analyzing Atrium Volume Designs for Hot and Humid Climates. Sustainability, 2019, 22, 6213.
13. Kirimtat, Ayca, et al. Multi-objective energy and daylight optimization of amorphous shading devices in buildings. Solar Energy2019, 185, 100-111.
14. Palmero-Marrero, Ana I., and Armando C. Oliveira. Effect of louver shading devices on building energy requirements.  Energy 2010, 87.6, 2040-2049. Doi: 10.1016/j.apenergy.2009.11.020
15. Liveri, Anna, Yota Xanthacou, and Maria Kaila. The google sketch up software as a tool to promote creativity in education in Greece. Procedia-Social and Behavioral Sciences2012, 69, 1110-1117.
16. Jaelani, A., and Y. S. Kusumah. The design of sketchup software-aided generative learning for learning geometry in senior high school. Journal of Physics: Conference Series. Vol. 1320. No. 1. IOP Publishing, 2019.
17. Maity, Atanu, et al. Design and Development of a Solar Artifact using Structural Analysis. Journal of Scientific and Industrial Research (JSIR),2020, 8, 740-745.
18. Harrison, Shaun, and Liben Jiang. An investigation into the energy performance gap between the predicted and measured output of photovoltaic systems using dynamic simulation modelling software—a case study. International Journal of Low-Carbon Technologies2018, 1, 23-29. Doi. 10.1093/ijlct/ctx016
19. Blewett Tymandra, Margaret Horne, and Robert Hill. Heliodon prediction of shading on building integrated photovoltaic systems. Conference Record of the Twenty Sixth IEEE Photovoltaic Specialists Conference-1997. IEEE, 1997, 541 doi: 10.1109/PVSC.1997.654351
20. Akbari, Hassan, et al. Effect of courtyards’ geometrical parameters on climate adaptability and shading performance in hot-arid climate of Yazd (Iran). Sustainable Energy Technologies and Assessments 2021, 48, 101594.
21. Mohamed, Khairul Azmi, Asmat Ismail, and Nur Azfahani Ahmad. Evaluation of daylighting performance in existing student residential building with internal partition. 2019 19-27.
22. Awad, Jihad, and Lamia Abd-Rabo. Daylight and Energy Performance Optimization in Hot-Arid Regions: Application and adaptation guide for designers in the UAE. Procedia Manufacturing2020, 44, 237-244.

 

Point 5: In addition, shading is highly dependent on the design of the building. For these to be more useful, it would be useful to give more details about how these tools work and shading analysis. How to set? And compare shading results between those heliodons and software tools.

We hope you consider that this point could be addressed in detail in another article because in this review we are limited to describing and classifying various types of heliodons, along with their operating principles and geometric features that affect their performance, including light sources, positioning mechanisms, and structures, and the computational tools for testing building shadow patterns and applications in architecture.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Author Response File: Author Response.docx

Round 2

Reviewer 2 Report

This paper’s methodology, structure, and clarity have greatly improved from the original version.

Point 1: In my opinion, however, it would be useful to give more details about how these tools work and shading analysis. How to set? And compare shading results between those heliodons and software tools. Providing these details will benefit this paper. Also, providing simple and concise explanations to this topic will help other researchers develop their research. Finally, these are important parts of an academic review paper. 

Point 2: Some paragraph consist of 1 sentence and 2 senteces (line 200, line 204, line 256, line 384, line 512, line 517, line 549, line 578, line 620). Please consider making the paragraph more complete.

Point 3: Please provide more data on 3D Sun-Path (line 516). Some explanations are too short, such as no adequate information is provided. 

Author Response

Dear Reviewer

Thank you very much for your time and your valuable contributions. Your comments have been very helpful to us to improve our writing and we are aware of all your points.

Point 1: In my opinion, however, it would be useful to give more details about how these tools work and shading analysis. How to set? And compare shading results between those heliodons and software tools. Providing these details will benefit this paper. Also, providing simple and concise explanations to this topic will help other researchers develop their research. Finally, these are important parts of an academic review paper.

At this point, we have decided to add a little section.

 

3.4. Sun shading by heliodon and tools software  

      To design shading systems, environmental performance-based solutions are typically taken into consideration. Performance parameters evaluate the performance of shading devices for occupants’ comfort, where direct solar shading, illuminance, daylight factor, luminance, glare, privacy and security, and outdoor visuals are considered requirements to meet the demands of occupants [105]. The basic functions of solar shading systems is to regulate the penetration of solar radiation in buildings and analyze the shading envelope external for effective shading control. Then the strategy would be to optimize solar gains in different seasons and compensate for the solar energy availability in the built environment, such as a sufficient day-lit indoor environment.

       Typically, In a heliodon, shading masks are used to visualize and quantify areas shaded. A shading mask is a diagram that replica the total shading generated by the path of direct solar radiation projected horizontally in a determined time. However, these techniques are not very effective in complex building models. In software simulation tools, the concept of the shading mask is composed of polygons that calculate, with enough precision, the projected area for efficiently determining hourly fractions or percentages of shading on a surface.

      To validate the use of the different sunlight tools, a house of 56 m2, located in the city of Saltillo, Coahuila, Mexico was modeled in Sketchup 2021 (Figure 13a), Revit 2023 educational (Figure 13b), and Helidon2 (Figure 13c) software packages. Its location was 25° 44” N latitude, 100.91 W longitude, and -6 time zone, without summertime. In each computational tool, sun exposure and shadow projection were modeled for the analysis day of December 21 at 2:00 p.m. on the main facade (SOUTH) of the house and the sidewall (EAST).

 

 

• (b)                                                    (c)

Figure 13 Shading analysis in a) Sketchup 2021, b) Revit 2023 (educational) and c) Helidon2

 

       The Sketchup 2021 results showed that the location of this software is done by georeferencing the site, i.e., the terrain data can be imported to Google Earth and the user can create a model based on the site.  It makes it much easier when the data is unknown and the user cannot go to the terrain. In addition, the drawing can be imported from an image and erecting walls as well as locating door and window openings. For the case of Revit 2023 (educational), the model is built directly in the program or can be imported from Autocad. The geographical location is entered through a tab of the program and can also be georeferenced by a Google earth map. Also, the user can unfold the solar mask and observe the position of the sun on the model. For the case of Heliodon2 software, the model is built in its own graphical environment by points or even by importing the building plan. The model is geographically located by feeding the specific location data by creating an element with the name of the site where the model is located.

      As shown in Figure 13, the projection of shadows is almost identical in the three programs, however, the visualization in Heliodon2 is more complex due to its image quality. Although it has the option of making the colors transparent, this is spliced with the drawing of the shadows. On the other hand, the optical properties of the windows can be indicated and so analyzing the amount of GSD that enters the interior space in the three software.

      Shadow evaluation for the heliodon case is more complex than using any computational tool, because the user must consider the method for shadow evaluation, lighting, heliodon calibration, model positioning and scale. According to the comparative work of the heliodon with a shadow simulation software carried out by Dalumo and Lim [150], it was found that both the software and the heliodon showed quite close results in shading performance with an acceptable level of accuracy incongruence. However, the simulations were carried out in considerably lesser time compared to the heliodon, which offers reliable and effective methods of assessing solar shading.

 

The following paragraph was also added in the conclusions

 

In the comparative analysis of virtual shading between; Sketchup, Revit, and Helidon, Heliodon resulted in the best image quality. Of course, for the same analysis in a heliodon is necessary to consider the methods for shadow evaluation, lighting, heliodon calibration, model positioning, and scale. However, the results are pretty close, reliable, and effective in all cases. Thus the virtual tools have the most significant advantage of carrying out the analysis in less time.

 

Point 2: Some paragraph consist of 1 sentence and 2 sentences (line 200, line 204, line 256, line 384, line 512, line 517, line 549, line 578, line 620). Please consider making the paragraph more complete.

This point was addressed as follows

From line 200

In 2015, Dolan [28] showed in detail the design of a heliodon developed by students of the California Polytechnic State University San Luis Obispo. This prototype is based on the Quality Function Development (QFD) method. This method was used to identify the design specification according to the type of users and their needs in the use of heliodon. As shown in Figure 3b, the prototype consisted of a frame, two circular arcs that hold the light source, and mechanisms for latitude, which are fixed to a cylindrical table. The final prototype met various specifications such as Weight, latitude, and Altitude Angle Range of Motion, and maximum tolerance in height, width, and length.

From line 204

In this configuration, the studied model stays fixed and the light source moves around the model to simulate sun motion and the shadows that the sun casts on the model. According to heliodons.org [40], these devices are called clear heliodons because the user can easily visualize shadows and understand the movement of the sun while the building model stays stationary. The operating principle is based on the flat surface of the heliodon is fixed in a horizontal position, and the light moves along three axes to adjust the latitude, day of the year, and time of day. In the literature, several designs have been reported, which are described as follows

From line 256

In this design, the user moves both heliodon's flat surface and the light source. The operating principle is based on the adjustment of the heliodon's flat surface in the desired latitude, and the light source is positioned according to the day of the year, and time of day. This type of heliodon offers more flexibility in the adjustment of the device; however, it has more mechanical components, and its cost can be high.

From line 384

The calibration methods are based on the empirical experiences of heliodon designers [56]. Therefore, there is a lack of standardized processes in the calibration and use of heliodon. It can lead to errors in the analysis [57,58]. For these cases, the user should consider the different types of errors (mechanics or visualization) and the impact on the shadow analysis. Two methods of verification have been used in the literature one is through computational tools and another is field verification.

From line 512

An example of the application of this tool has been described in [22,23], where the authors used this software as an educational tool for explaining the geometry, distance, and angle in space. It was found that the students can interpret, deduce data and compare it with the actual models.

From line 517

This is an online and free platform that links the graphical location and solar position throughout the year with the Google Earth map. It contains three windows, in one of them the user can view the location of the place through Google maps, in another window the shadows and the apparent path of the sun in the buildings can be visualized. Finally, in another window, the length of the Analemma graph or different sun path options can be seen. The operational principle of this platform is based on using google maps to locate the place of interest and adjust the options of day, hour, latitude, and longitude, when the options change, different 2D sun path projections appear on the platform [76].

From line 549

Design-Builder is a software tool based on Energy Plus, which combines a 3D building model with dynamic energy simulation. This software was developed by the American Energy Association in 2011 [82,83]. It evaluates buildings in terms of their overheating, energy consumption, and shading parameters. Design Builder has many powerful toolboxes, for the temperature, velocity, pressure distribution, and determination of the capacity of the heating and cooling equipment. This software can simulate a complex installation, and the simulation can be linked-to Energy Plus.

From line 578

DIVA-for-Rhino, distributed by Solemma LLC, consists of a collection of tools that make it possible to optimize daylighting and energy modeling. It focuses on analyzing the environmental performances in buildings and urban landscapes. This software includes radiation maps, photorealistic renderings, climate-based daylighting metrics, annual and individual time step glare analyses, LEED and CHPS daylighting compliance, and single thermal zone energy and load calculations [89-91]. Its interactive platforms help users to quickly select library materials; schedule, add, or remove components and control the complexity of the scripts. However, DIVA-for-Rhino is not free software [92].

From line 620

An example described in the literature about the use of these tools is shown in [100], where the authors assessed the thermal performance of an opaque ventilated façade in the summer period using ESP-r software. The simulation model was calibrated with experimental measurements. The details of the process of calibration are described carefully. The results showed a ~7% difference between predicted and measured results.

 

Point 3: Please provide more data on 3D Sun-Path (line 516). Some explanations are too short, such as no adequate information is provided.

This point was managed as follows.

3.1.8 3D Sun-Path

This is an online and free interactive platform that links the graphical location and solar position throughout the year with the Google Earth map in real-time. It contains three windows, in one of them the user can view the location of the place through Google maps, in another window the shadows and the apparent path of the sun in the buildings can be visualized. Finally, in another window, the length of the Analemma graph or different sun path options can be seen. The app started as an experiment to see just how responsive I could make the generation and display of 3D Sun-path diagrams and shadow projections using JavaScript. Now the operational principle of this platform is based on using google maps to locate the place of interest and adjust the options of day, hour, latitude, and longitude, when the options change, different 2D sun path projections appear on the platform [76].

 

 

 

 

Author Response File: Author Response.pdf