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RESEARCH PAPER / НАУЧНАЯ СТАТЬЯ УДК 628.8:624.02
DOI: 10.22227/1997-0935.2022.2.149-158
A field study on effects of openings on thermal performance of natural cooling efficiency for atrium buildings
Hong-Tham T. Pham1,2,3, Aleksey K. Solovyev3, Sergey S. Korneev3
1 Ho Chi Minh City University of Technology (HCMUT); Ho Chi Minh City, Vietnam; 2 Vietnam National University Ho Chi Minh City (VNU-HCM); Ho Chi Minh City, Vietnam; 3 Moscow State University of Civil Engineering (National Research University) (MGSU);
Moscow, Russian Federation
ABSTRACT
Introduction. In this paper, we investigate the temperature stratification of buoyancy-driven natural ventilation of the atrium of building at ULK-MGSU through field experiments. The process of ventilation with different openings ratios in the translucent roofing and ground floor entrance doors are analyzed to reveal the physical insights. With this aim, the main focus of the study is to consider the temperature fields during cooling the atrium premises that increase the thermal performance of the administrative building at ULK in the summer. An expensive ventilation solution by the optimum design of the inlet-to-outlet opening area ratio in the translucent roofing covering is utilized to improve thermal comfort without reducing the level of illumination.
Materials and methods. In this study, field measurements were applied to investigate and compares temperature stratification by floors of naturally ventilated ULK atrium building with different outlet sizes and locations under hot period conditions. The results of field measurement was utilized to develop the baseline model for the computational fluid dynamics (CFD) simulation in future work.
характеристики при естественном охлаждении здании с атриумами
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Results. These results reveal that the sizes and locations of openings in the atrium building affect on modification of the n h
indoor thermal condition. Moreover, energy efficiency is improved thanks to buoyancy-driven changes in air flow rate in an ^ j
atrium with multiple openings. ^ X
Conclusions. This study shows that it can be possible reduce indoor air temperatures by 5 °C during the summer period. In fl^
addition to the large inlet openings at different atrium levels, a high ratio of the outlet opening area (>10 %) is recommended. U o
The existing atrium of the building was opened 5 % of the total top-glass roof area, which helps to improve the performance . ^
of buoyancy-driven ventilation in order to achieve better atrium cooling performance and prevent the detrimental reverse air O m
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KEYWORDS: flow air enhancement, thermal stratification, thermal performance, thermal comfort, natural ventilation, J 9 cooling performance, energy performance, atrium, energy-efficient buildings, stack effect o 9
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Acknowledgment. We acknowledge the support of time and facilities from Moscow State University of Civil Engineering a 9 (National Research University), (MGSU) for this study. 0 5
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FOR CITATION: Hong-Tham T. Pham, Solovyev A.K., Korneev S.S. A field study on effects of openings on thermal O § performance of natural cooling efficiency for atrium buildings. Vestnik MGSU [Monthly Journal on Construction and s Architecture]. 2022; 17(2):149-158. DOI: 10.22227/1997-0935.2022.2.149-158 (rus.). U S
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Corresponding author: Hong-Tham T. Pham, ptham0825@gmail.com. O z
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Натурное исследование влияния проемов на тепловые > 80
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Фам Тхи Хонг Тхам1'2'3, Алексей Кириллович Соловьев3,
Сергей Сергеевич Корнеев3 о о
1 Технологический университет Хошимина; г. Хошимин, Вьетнам; д 1
2 Вьетнамский национальный университет Хошимина; г. Хошимин, Вьетнам; ® .
3 Национальный исследовательский Московский государственный строительный университет . п
(НИУ МГСУ); г. Москва, Россия ( П
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АННОТАЦИЯ
Введение. Исследуется влияние атриума на температурную стратификацию при естественной вентиляции внутри 2 2
помещений учебно-лабораторного корпуса (УЛК) МГСУ с помощью натурных экспериментов и анализируется фи- 2 2
зическое понимание процесса вентиляции при различном соотношении площади приточных отверстий и вытяж- 2 2 ных отверстий в светопрозрачной кровле. Исходя из этого целью исследования является: изучение температурного
© Hong-Tham T. Pham, Aleksey K. Solovyev, Sergey S. Korneev, 2022
Распространяется на основании Creative Commons Attribution Non-Commercial (CC BY-NC)
режима при охлаждении помещений атриума для улучшения тепловых характеристик административного здания УЛК летом с помощью недорогого естественного вентиляционного решения путем оптимального соотношения площади входных и выходных отверстий внизу и в светопрозрачном кровельном покрытии для повышения теплового комфорта без снижения уровня освещенности.
Материалы и методы. Использованы методы натурного исследования. Проведены натурные измерения для изучения и сравнения температурной стратификации по этажам здания с естественной вентиляцией с различными размерами и расположением отверстий в условиях жаркого периода года. Информация об измерениях в натурных условиях затем будет использована для разработки базовой модели в будущей работе по компьютерному моделированию потоковых процессов на базе программы для гидродинамики (CFD).
Результаты. Результаты доказывают, что размеры и расположение отверстий в здании атриума влияют на изменение теплового режима в помещении, а энергоэффективность улучшается за счет изменения скорости воздушного потока, обусловленного движением в атриуме с отверстиями разных размеров.
Выводы. Исследование показало, что естественная вентиляция может снизить температуру воздуха в помещении на 5 °C в летний период. В дополнение к большим входным отверстиям рекомендуется большее соотношение площади входного отверстия к площади выходного отверстия (>10 %). В существующем здании атриума было открыто 5 % от общей площади верхней стеклянной крыши. Это помогает улучшить производительность естественной вентиляции за счет циркуляции воздуха и достичь лучшего охлаждения атриума и предотвратить вредное обратное движение воздуха.
КЛЮЧЕВЫЕ СЛОВА: улучшение циркуляции, температурная стратификация, тепловые характеристики, тепловой комфорт, естественная вентиляция, эффективность охлаждения, энергоэффективность, атриум, энергетические показатели, эффект стека
ДЛЯ ЦИТИРОВАНИЯ: Фам ТхиХонг Тхам, Соловьев А.К., Корнеев С.С. A field study on effects of openings on thermal performance of natural cooling efficiency for atrium buildings // Вестник МГСУ. 2022. Т. 17. Вып. 2. С. 149-158. DOI: 10.22227/1997-0935.2022.2.149-158
Автор, ответственный за переписку: Фам Тхи Хонг Тхам, ptham0825@gmail.com.
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INTRODUCTION
Over the recent years, atria have grown in popularity in modern architecture. Atria provide space and light, hence, they become effective building ventilation elements. Therefore, this function has boosted the popularity of atria in large shopping centres, hotels, educational buildings, commercial buildings, and most public buildings. Complicated benefits of an atrium and some other contradictions make their design a challenging process. Architectural, functional, economic, environmental, structural and psychological aspects must be considered in the atrium design. Core issues should be addressed at the early design stage [1]. Besides, well-designed atria can help to significantly save energy, ensure indoor thermal comfort by taking advantage of natural ventilation that needs no mechanical equipment, and reduce demand for space conditioning [2]. In contrast, a poorly designed atrium can result in uncomfortable daytime temperatures and additional air conditioning loads [3]. In addition, designers have to encounter several problems related to the building function and climate zones. In particular, each design decision is often based on the local climate and climatic conditions. However, environmental aspects of atrium design have not been taken into account yet. A few studies address the thermal performance of large glass spaces, influenced by such factors as thermal stratification and the maximum temperature.
According to the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE, 2010), Standard 55-2010 (ASHRAE, 2010) mentions notoriously uncomfortable glass box buildings although large, sophisticated, expensive and maintenance-inten-
sive systems are used1. In addition, problems of heat inside atria, built in hot climates, such as excessive sunlight, glare, and high temperatures lead to an increase in the energy demand of buildings [4]. Overheating is the major problem of atria during hot days that contributes to the thermal comfort reduction. The reason for overheating is that a top-lit atrium normally uses transparent or translucent roof material that allows a certain amount of daylight into the building. One standard example is the use of skylight coming through the atrium roof. Nevertheless, the ratio of the glazing area influences the heating and cooling of the atrium area [5]. Excessive glazing is inappropriate for hot climates as it increases the solar radiation penetrating into the atrium through glazed surfaces, boosts the heat gain, which subsequently raises the indoor air temperature. In addition, a multi-storied atrium with a glass roof, built in hot and humid climates, will also suffer from high air temperature stratification immediately below the rooftop [6].
Many studies have been conducted to improve indoor thermal conditions of atria. Natural ventilation in atria is the main passive cooling strategy which is initially caused by buoyancy-driven phenomena. It has been implemented all over the world as a key passive design technology employed within the framework of a sustainable approach to the architectural design of green buildings [7]. It ensures a healthy and comfortable environment by bringing fresh air into a building, and it has been considered an effective strategy towards better
1 ANSI/ASHRAE Standard 55-2017. Thermal Environmental Conditions for Human Occupancy: American Society of Heating, Refrigerating and Air-Conditioning Engineers, 2017.
indoor air quality and thermal comfort [8]. Hence, this strategy is responsive to climate conditions which vary from one region to another. The driving forces of natural ventilation depend on wind effects, thermal buoyancy, their combination in naturally ventilated buildings, the heat at the top of the atrium excited by the wind driving force, and stack effect [9]. Ventilation driven only by buoyancy forces is usually the worst case for natural ventilation, especially on a warm and windless day. High density outdoor air enters low-level openings and is heated by warmed surfaces in a building. Heated air becomes lighter and leaves the building through high-level openings [10]. Therefore, atria have gained popularly in many large office buildings. In general, a buoyancy-driven flow is generated by the temperature difference, which makes the air density change. Moreover, the difference in height makes the air pressure vary [11]. In this case, an atrium has several strengths: it is a vast indoor space and a heat source that adsorbs heat emitted by a huge number of moving people. A large indoor and outdoor pressure difference results in effective natural ventilation. In practice, thermal stratification is developed between a low-level inlet and a high-level outlet [12]. The main objective of proper ventilation is to generate a sufficient ventilation rate [13]. Therefore, temperature stratification and buoyancy-driven ventilation have always been major concerns of natural ventilation systems.
However, it is obvious that the outlet opening state (opened/closed) has the most significant effect on both indoor temperatures and the airflow passing through the atrium building. For example, open stack vents allow nearly twice as much air to flow through the model and reduce the vertical temperature gradient of 7 °C. In the case of closed stack vents, the flow pattern changes and the air flows into surrounding rooms through openings on upper floors. Nevertheless, the location of outlet openings has the lowest thermal effect on atria, but the location of openings connecting the atrium and surrounding spaces has a significant influence on the airflow pattern. Therefore, a change in the location of an opening can bring the ambient air flow into the air-conditioned zone. Furthermore, a low inlet to outlet area ratio in a buoyancy-driven natural ventilation system of an atrium rises the rate of the airflow.
A great number of researchers studied different design parameters to improve the thermal performance of an atrium by investigating the effect of the opening design [14-16], the atrium shape [17, 18] or the atrium roof design [19]. For this purpose, Lin and Linden [20], Holford and Hunt [21], and Wang, Huang [22], acting independently, used theoretical and experimental methods to evaluate the thermal performance of atria featuring openings that had different characteristics (size, location, and state). Of all these characteristics, the opening size plays a more significant role. In general, the stratification of the air temperature in an atrium reduces significantly with the increase in the size
of openings [23]. However, a strong and well-distributed airflow through the building needs a well-balanced ratio of inlet to outlet openings. For example, in temperate climates, featuring buoyancy-driven ventilation, an atrium enhances the airflow throughout a storey if only its upper openings are of medium size, while its lower openings are sufficiently small [24]. In tropical regions, featuring pressurized ventilation, a sufficiently lower outlet to inlet opening area ratio (1 > n) can improve the thermal performance on other levels occupied by residents. Besides, a large number of openings rises the airflow rate through the atrium, but reduces the air flow rate through each floor that increases the temperature at almost all heights of the building [25].
The influence of areas of inlet and outlet openings on the thermal performance improvement, which enhances the efficiency of natural ventilation, has not been adequately studied. Although many studies have been focused on the efficiency of the areas of openings in an atrium, the knowledge about the passive design of atria is insufficient, given its complexity and lack of accurate measurement tools. As for the thermal performance, a few studies have been conducted to investigate real indoor thermal conditions using field measurements and monitoring [26, 27]. Many of the relevant studies were focused on the validation of analytical methods. If compared with other similar studies, the researched parameters of naturally ventilated atria were far from being adequate. As a result, further research on innovative solutions for naturally ventilated atria and reliable testing procedures are necessary. Towards this end, the main objectives encompass a comparative study on the areas of bottom and top openings of an atrium to be conducted by means of monitoring and site measurement.
MATERIALS AND METHODS
The main methods employed in this section are well-known research methodologies used in previous studies. A thorough study of the atrium performance is limited due to inaccuracies and limitations imposed by the available prognostication tools and controlled experiments2. In general, to assess the thermal performance of an atrium, different methods such as the field study, analytical models, mathematical, numerical modeling, small scale simulation using computer modeling and their combination have been applied. Full-scale field experiments are preferable to other approaches due to the problem-free data collection and controllable conditions, and the findings of such experiments reflect real conditions without numerous assumptions.
Field measurements were taken to study and compare the thermal stratification between the floors of a naturally ventilated atrium building featuring different locations and sizes of openings in hot weather.
2 ASHRAE Standard 62-2001: Ventilation for acceptable indoor air quality, American Society of Heating, Refrigerating and Air-Conditioning Engineers. 2001.
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Description of the atrium building
Proper atrium buildings that have openings at the top and bottom are relatively rare. Temperature values and flow rates in a standard atrium building are influenced by large spaces and numerous uncontrolled factors. The main building of the Moscow State University of Civil Engineering (MGSU), located in Moscow, was chosen for the case study as shown in Fig. 1 a.
The building has five floors; it is nearly rectangular, and its dimensions are 42.2 x 60.2 x 23.7 m (width/ length/height), and the total floor area is 12,000 m2. This is the atrium space shown in Fig. 1 b. The floor plan of the atrium building is shown in Fig. 2 a, b. In addition to the entrance, the ground level as well as the first floor are connected to the atrium. The second, third, fourth and fifth floors are connected to the central atrium that is surrounded by open classroom spaces. The atrium space is located in the middle of the building and surrounded by rooms or spaces, with a rectan-
gular floor plan dimensions of 17.4 x 21.2 m. Moreover, the atrium is lit from above by the skylight. The atrium itself is not air-conditioned although the surrounding office spaces are. Table 1 shows the properties of the atrium spaces in the MGSU building.
Measurement methods
This field experiment was conducted for approximately 15 consecutive days from July 15 to August 1, 2021 in the MGSU atrium building to cover cloudy and clear days. The measurement time was 9:30 to 11:00 am. The location of the measurement tool in each atrium is shown in Fig. 3.
Weekends were chosen to reduce the impact on occupants. The solar gain in the daytime contributed to the buoyancy effect. No mechanical ventilated system is installed there. Hence, only natural ventilation will be considered inside the atrium. Although corridors are connected to the stairwell on every floor, all doors were closed to avoid the air exchange. Testers monitored the doors during the whole process to prevent any unexpected problems. All doors leading to
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Table 1. Atrium building characteristics ULK-MGSU
Parameter Value
Building shape Rectangular
Area 12,000 m2
Building height, length, width Height: 23.7 m 5 stories, 1st story — 4.8 m, 2nd-5th stories — 3.6 m each Length: 60.2 m Width: 42.2 m
Building orientation North-east (N-E)
Atrium plan area 17.4 x 21.2 m
Atrium top glazing ratio 100 %
Type of atria Centralized atrium
Openable area of the glass roof 5 %
the corridors were closed from 9:30. To monitor the effect of different opening sizes, top and bottom doors were completely open from 9:50 to 10:30, and closed from 10:30 to 11:00. Temperatures were logged every 10 min to register real-time changes (9:30, 9:35, 9:40, 9:45, and 9:50). Indoor environment data were recorded for the field measurements every 10 minutes. We used the thermal hygrometer (Testo 625) to study the influence of inner surfaces, including four glass walls. The parameters of the measurement instrument are presented in Table 2. It measures environment parameters such as relative humidity and air temperature. However, air flows and relative humidity were not measured since the air flow speed inside the atrium space was too low (<0.1 m/s). As shown by the anemometer, readings ranging from 0.03 to 0.15 were registered at selected points on the three levels on the first day.
The following four different cases were chosen:
Table 2. Measuring equipment parameters
Case 1: Completely open ground floor openings with the area of 8.28 m2; the ventilation system is turned off and outlet openings in the translucent roofing with the opening area of 19.6 m2 are completely open.
Case 2: Closed ground floor openings; the ventilation system is turned off, and outlet openings in the translucent roofing is closed.
Case 3: Closed ground floor openings; the ventilation system is turned off, and outlet openings in the translucent roofing with the area of 19.6 m2 is completely open.
Case 4: Completely open ground floor openings with the area of 8.28 m2; the ventilation system is turned off, and outlet openings in the translucent roofing is closed.
Each case is designed to test the significance of a particular strategy like the impact of the stack effect.
RESULTS OF THE RESEARCH
1. Case 1 and Case 2 temperature variation
In general, these field measured results clearly show that the air temperature stratification within the atrium reduced significantly with an increase in the size of openings. For the size of low- and high-level openings of 3.6 m2, the difference in the air temperatures between the lower level and the next upper level floors was generally about 0.5-1 °C for Case 1 and Case 2; and it was 1-2 °C for Case 3 and Case 4. For instance, Fig. 4 a, b shows the air temperature breakdown by the floors with closed outlet openings in the translucent roofing for cases with different opening locations at the top of the atrium. As shown in Fig. 4 a, in the case of closed outlet openings in the translucent roofing, the temperature at 4 different points on the 5th floor varied from 35 to 37.7 °C. As for the measurement results in the case of open top doors, the openings reaching 10 % of the total glass roof area showed that the temperature varied from 32.5 to 34.4 °C at four different points on the 5th floor. These measurements were taken with the top door closed as shown in Fig. 4 b.
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Testo 625 humidity/temperature measuring instrument, including plugin humidity probe head, battery and calibration protocol
Temperature t_a, °C: -10 to +60 °C; 0.1 °C; ±0.5 °C
Humidity RH, %: 0 to +100 %; 0.1 %; ±2.5 %
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Fig. 3. Location of points of measurement on each floor
2. Case 3 and Case 4 temperature variation
The temperature measurements taken when the top openings are open and closed are shown in Fig. 5 a, b. These measurements were taken when the bottom doors were completely open. The results show that in the case of closed openings, the temperature at four different points on the five floors of the building varies from 34.1 to 36 °C. Meanwhile, if 10 % of the total glazing area is open, measurement results show that the temperature ranges from 32.3 to 33.2 °C at 4 different points on the 5th floor, which is 2-3 °C lower than in the case of closed openings. This shows an increase in the effectiveness of an atrium for reducing the daytime temperature by maximizing the size of openings in the atrium building.
As shown in Table 3, Case 1 is the best temperature mode in the atrium. However, Case 2 has a tem-
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Variable Case 1 Case 2 Case 3 Case 4
Measuring point 1 32.5 33.2 33 32.3
Temperature, °C Measuring point 2 33.1 34 34.1 32.5
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perature mode that is slightly better than the one in Case 3. In Case 4, the highest temperature (35-37.8 °C) is shown in Table 1. These results reveal that the effect of different compositions of inlet and outlet openings on the indoor thermal condition and energy efficiency is improved by buoyancy-driven air flow changes in an atrium having multiple openings.
The indoor air temperature was relatively stable on every floor during the experiment. However, the air temperature kept rising on the way from the bottom to the top. This air gains heat from hot surfaces when passing through them and then enhances the buoyancy effect. These results prove that well-mixed conditions in the atrium buildings used in many studies are unsuitable when cross-section areas are small. The gradual increase in the temperature fields along the vertical direction inside atriums reflects the real state of affairs.
We used these results and full-scale measurement data to study the effect of different of outlet opening locations and sizes at the top of the atrium. They have little influence on the velocity and temperature fields inside the building. In addition, the higher the floor,
the higher the temperature. The results show that the lobby area below the translucent roof was extremely hot due to the coupling of the high mean radiant temperature and stratified hot air. According to the design guidelines, the indoor temperature shall vary between 25 and 27 °C in the atrium lobby and corridors [28]. According to Fig. 6, the size of the outlet openings is about 10 % of the total glazed atrium area. Although inlet openings are necessary, the opening area does not need to be very large because if the area of openings rises from 50 to 100 %, it cannot make any significant difference. Openings have little effect on temperature fields. Therefore, they can be used to maximize the airflow rate, it should reduce overheating in the atrium lobby. In addition, it can reduce the indoor air temperature by 5 °C on a hot day during the summer period when the outlet opening ratio exceeds 10 % of the total glass roof area in the atrium building, and it helps to improve the buoyancy-driven ventilation performance to achieve the optimum atrium cooling and prevent detrimental reverse air motion (Fig. 6).
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Fig. 6. Section A-A of the atrium building: a — current area of openings; b — recommended area of openings
To sum up, we believe that the thermal performance of an atrium can be improved by changing the size and position of the openings, provided that the upper atrium opening is large enough, and that the lower atrium opening is small enough with varying degrees of opening on hot days to boost flows in the adjacent areas and determine the optimum airflow rate in these spaces. The research based on the field experiments aimed at finding the efficient atrium design parameters and the thermal effect identified in the course of an experiment will help designers and engineers to decide upon the opening design in naturally ventilated buildings and provide a strong background for further research required to develop empirical guidelines for the future design of atria.
CONCLUSION AND DISCUSSION
This study reports the effects of different opening area ratios on improving the internal thermal conditions of an atrium and a lobby on hot and clear summer
days. Generally, the difference between the average air temperature on the first floor and the fifth floor varies from 1 to 5.5 °C. Meanwhile, if the outlets on the top of the atrium are completely open, the difference between the average air temperatures on these two floors varies from 1 to 2.5 °C. These results clearly show that the difference in the outlet locations and sizes on the top of the atrium has a strong effect on the temperature fields inside the buildings. Particularly, the air temperature stratification within the atrium reduces significantly with an increase in the locations and sizes of openings on the top of the atrium. The atrium demonstrates the highest thermal performance in Case 1, if the bottom and top doors are completely open, and occupants experience maximal comfort, especially at the points beside the atrium envelope. Given these results, the size of outlet openings (>10 %) is recommended to achieve the optimum atrium cooling performance, and large inlet openings should be added at different atrium levels. This atrium building had 5 % of the total top-glass roof
area open, which helps to improve the buoyancy-driven ventilation performance to achieve the optimum atrium cooling performance and prevent detrimental reverse air motion, but it is not enough for more or less comfortable conditions.
These results and conclusions will help architects and engineers to make informed decisions about the anticipated thermal environment and airflow conditions. Consequently, they might design optimal openings and their sizes, as well as the number of floors. In addition, these findings help them to save the evaluation time for new cases, predict the indoor comfort, help designers to evaluate the ventilation performance; choose the optimal design of building openings, and reduce the energy
consumption by mechanical ventilation systems. Furthermore, the effect of the atrium size, geometry, roof shape, material, insulated outdoor walls on their cooling efficiency also needs to be studied in further research projects to increase energy savings.
Even though considerable discrepancies were observed among the daily measured thermal parameters over the 15-day monitoring period, particularly due to unstable weather conditions, this study is expected to provide a clear picture of the indoor thermal environment in the atrium in the hot period. Since the measuring period was rather short, it is, therefore, recommended that monitoring periods should be longer for the research findings to be better substantiated.
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Received January 10, 2022. Adopted in revised form on February 28, 2022. Approved for publication on February 28, 2022.
Bionotes: Pham Thi Hong Tham — Lecturer at Laboratory of Building Physics, Faculty of Civil Engineering; Ho Chi Minh City University of Technology (HCMUT), Vietnam National University Ho Chi Minh City (VNU-HCM); 268 Ly Thuong Kiet st., District 10, Ho Chi Minh City, Vietnam; postgraduate student of the Department of Design of Buildings and Structures; Moscow State University of Civil Engineering (National Research University) (MGSU); 26 Yaroslavskoe shosse, Moscow, 129337, Russian Federation; SPIN-code: 9515-2143, Scopus: 57222268423, ResearcherID: rid21029, ORCID: 0000-0002-7418-2084; ptham0825@gmai.com; jy jy Aleksey K Solovyev — Doctor of Technical Sciences, Professor, Professor of the Department of Design of Buil-
dings and Structures; Moscow State University of Civil Engineering (National Research University) (MGSU) j? $ 26 Yaroslavskoe shosse, Moscow, 129337, Russian Federation; SPIN-code: 3821-9431; kafedraarxitektury@yandex.ru
Sergey S. Korneev — Senior lecturer of Department of the Department of Design of Buildings and Structures
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l_ Contribution of the authors: all authors contributed equally to the writing of the article.
Conflict of the interests: the authors declare no conflicts of interest.
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со 2 он 10, 14-й квартал, ул. Ли Тхвюнг Киет, д. 268; аспирант кафедры проектирования зданий и сооружений; Наци-
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ю о ORCID: 0000-0002-7418-2084; ptham0825@gmai.com;
g с Алексей Кириллович Соловьев — доктор технических наук, профессор, профессор кафедры проекти-
rj о рования зданий и сооружений; Национальный исследовательский Московский государственный строительный университет (НИУ МГСУ); 129337, г. Москва, Ярославское шоссе, д. 26; SPIN-код: 3821-9431;
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41 Сергей Сергеевич Корнеев — старший преподаватель кафедры проектирования зданий и сооружений;
заведующий лабораторией строительной физики; Национальный исследовательский Московский государ-¡7) ственный строительный университет (НИУ МГСУ); 129337, г. Москва, Ярославское шоссе, д. 26; SPIN-код:
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5327-1094; KomeevSS@mgsu.ru.
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