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Comparative analysis of thermal comfort in the traditional and smart buildings

Comparative analysis of thermal comfort in the traditional and smart buildings EEPES-2022 IOP Publishing Journal of Physics: Conference Series 2339 (2022) 012024 doi:10.1088/1742-6596/2339/1/012024 Comparative analysis of thermal comfort in the traditional and smart buildings L Dębska Faculty of Environmental, Geomatic and Energy Engineering, Kielce University of Technology, Poland E-mail: [email protected] Abstract. All the constantly growing thermal requirements of people pose new challenges for designers in the field of modern and smart construction. The main idea of such buildings is to ensure the best possible conditions for the internal environment, especially in public facilities. In Poland, the majority of university buildings are traditional buildings that have been modernized, thus increasing the feeling of thermal comfort by people. The aim of this article is to conduct a comparative analysis of two rooms, for the smart building "Energis" and the traditional building "B" at the Kielce University of Technology. The testo 400 device was used to carry out the study, which, through parameters taken from the environment, enabled the calculation using the ISO 7730 standard, Predicted Mean Vote (PMV) and anonymous questionnaires from which an averaged Thermal Sensation Vote (TSV). The temperature of the o o first room was 26.7 C, and the temperature of the second was 23.6 C. The results turned out to be intriguing as the analysis showed that the students were not satisfied with the conditions in the smart building. 1. Introduction Thermal comfort is a state in which every person will not be too hot or too warm. The first studies that took into account thermal sensation were initiated by Fanger in the 1960s and 1970s. It was Fanger who created the formula that is used to this day in the ISO 7730 standard [1,2]. This formula is defined by an indicator such as Predicted Mean Vote (PMV), which indicates people's thermal sensation. For its calculations, it is necessary to know the internal parameters of the environment, such as air temperature, humidity, average temperature of radiation, air velocity, and clothing insulation. In addition, surveys are also carried out in which the respondents themselves determine how real they feel in the rooms. On the basis of the completed questionnaire, the average of the responses with the Thermal Sensation Vote (TSV) index. The knowledge of TSV and PMV for the tested objects enables the comparison of places that meet the thermal acceptance of people and the standard. In the literature review, a lot of research works related to TSV and PMV indicators. However, there is still almost no research (except for studies conducted by the author [3] and the other researchers from Kielce University of Technology [4,5] comparing modern construction with traditional construction. Shin et al. [6] analysed the PMV and TSV for CO in the university library, thus proposing a new air-conditioning solution that improves people's thermal sensations. The study found that as CO increased, people became hotter. Their thermal condition improved after the improvement of the air conditioning control unit. Elnaklah et al. [7] examined as many as 1101 people with 31 Content from this work may be used under the terms of the Creative Commons Attribution 3.0 licence. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI. Published under licence by IOP Publishing Ltd 1   EEPES-2022   IOP Publishing Journal of Physics: Conference Series 2339 (2022) 012024 doi:10.1088/1742-6596/2339/1/012024 buildings, including green construction in four countries. Despite the fact that 58% of the given internal parameters were within the norm, for 40% of the respondents they were only acceptable. Additionally, the respondents described their feelings during the summer as too overcooled, feeling discomfort in this connection. What is more, Hussaro et al. [8] from Thailand studied students, checking the extent of their thermal comfort and reducing the consumption of the energy sector used to supply air conditioning. Measurements were made from the temperature of 25-28 C, at various air velocities, from 0.5-0.9 m / s. The results provided information that a set temperature of around 25 C degrees could be changed to 26-28 C while increasing air velocity in the room and thus reducing energy costs by around 7.30% when the temperature is raised by 1 C. In addition, the authors of the work [9], also from Thailand, obtained similar results, in which the analysis determined similar parameters of thermal compartment at 26 C at 50-60% humidity. In a smart building, the author of the work [10] checked how women and men felt thermal comfort. 164 people were examined, including 97 men and 67 women for the temperature range from 19.3 C to 27.6 C. It turned out that the TSV of women and men was a feeling of comfort, but the women felt more cold, and the men felt too warm. Moreover, Mors et al. [11] focused on the thermal sensations of children aged 9 to 11 in rooms that could not be air-conditioned in the Netherlands. The research period covered winter, spring and summer. According to the questionnaires, the insulation of clothing according to children was 0.9 clo for the winter period and 0.3 clo for the summer period. Significant differences have been observed between TSV and PMV, reporting that PMV is not able to actually determine the real thermal sensation of students. Also, the PMV index has been analysed by the authors [12,13]. This work will focus on the comparison of two educational buildings - smart building and traditional building, analysing thermal comfort using the TSV and PMV indicators. 2. Materials and methods In April (spring conditions in Poland), thermal comfort tests were carried out to compare thermal sensations in the traditional "B" building and in the smart "Energis" building belonging to the Kielce University of Technology. The first one was built in the 1960s. Its modernization was carried out 10 years ago. The second building under study, "Energis", was built in 2012. It uses all kinds of renewable energy sources (heat pumps, wind turbine, etc.) to be energy independent and the Building Manager System is responsible for regulating lighting during the day and night, as well as energy produced and consumed. Both examined buildings are shown in figure 1. a) b) Figure 1. Photos of the buildings covered by the study: a) traditional building called "B" and b) smart building called "Energis". 2 EEPES-2022 IOP Publishing Journal of Physics: Conference Series 2339 (2022) 012024 doi:10.1088/1742-6596/2339/1/012024 For both tested objects, two the same measurement methods were used with the participation of students completing the questionnaires determining thermal sensations and with the use of the Testo 400 environmental meter. In the first method, the respondents were asked to describe their feelings in terms of temperature or humidity, and thermal preferences. The questionnaires provide information about the health and physical activity of the surveyed people. The patient's illness may cause the temperature to feel cooler, and the person who was running on the treadmill before coming to the test, will have a higher heart rate, which will cause a false image of their thermal sensations. Moreover, the questionnaire helps to determine the insulating power of the clothing called "clo" of the respondents and to calculate the Body Mass Index "BMI". The second method is based on an environmental gauge which takes internal parameters such as air temperature, humidity, light intensity, carbon dioxide or air velocity from the tested environment. Obtaining these data enables the calculation of the formula for PMV from the ISO 7730 standard. The measurement itself lasted over 15 minutes so that all data stabilized. After this time, the results were saved. In total, 25 people participated in the study. In "Energis" 13 people were examined, where men constituted the majority of the studied group, equal to 62%, and women - 38%. In contrast, in the traditional building "B", the study covered 12 people, where women only constituted 17% of the respondents, and men 83%. The age range for both groups was 21 to 52 years old (one teacher). The rooms under study are situated towards the west. The "Energis" is on the second floor, and in the "B" building, it is on the fourth floor. The study was conducted on the same day, at a similar time. Figure 2 shows the tested room in building "B" with a measuring station. Figure 2. A classroom with a microclimate meter. 3. Results and discussion The obtained parameters of the internal environment are summarized in table 1. Table 1. Comparison of parameters from the tested rooms. Air Temperature Carbion Air Speed Black Ball Relative o o ( C) Dioxide (ppm) (m/s) Sphere ( C) Humidity (%) Traditional 23.6 660 0.06 23.7 26.29 building “B” Smart building 26.7 1453 0.07 26.3 29.13 “Energis” 3   EEPES-2022   IOP Publishing Journal of Physics: Conference Series 2339 (2022) 012024 doi:10.1088/1742-6596/2339/1/012024 The biggest differences can be seen between the air temperature, which was 3.1 C, and thus between the black sphere temperature, equal to 2.6 C, and the concentration of carbon dioxide, which was twice as high in the "Energis" room. Additionally, the average thermal resistance of clothing of 0.68clo for both studies was used for the calculations. The respondents described their feelings according to a seven-point scale from -3 to +3, where -3 describes the temperature as too cold and +3 describes the temperature as too hot. Figure 3 presents a summary of the TSV results obtained for two rooms. Traditional building B Smart building Energis -3 -2 -1 0 1 2 3 TSV Figure 3. Respondents' answers describing their current thermal sensation (TSV) for building "B" and "Energis": -3 – too cold; -2 – too cool; -1 – pleasantly cool; 0 – comfortable; +1 – pleasantly warm; +2 – too warm; +3 – too hot. Figure 3 shows that people studying in a classroom located in a traditional building felt thermal comfort by selecting answers 0 and 1. Contrary to the classroom in "Energis", where as many as 46% of people found the room temperature too warm. Thus, all the room users in the traditional building accepted the environment, while for almost half of the people in “Energis” is was beyond the acceptable TSV range of -1 to +1. It is definitely delated to higher temperature in Energis of almost 27 C. Besides the high carbon dioxide level there might be responsible for such thermal sensations. Naturally, it also indicates poor air exchange and ventilation problems. No less important factor that people feel is relative humidity. The respondents' assessment of humidity is shown in figure 4. Traditional building B Smart building Energis -2 -1 0 1 2 AHV Figure 4. Relative humidity assessed by students: -2 – too dry; -1 – quite dry; 0 – pleasantly; +1 – quite humid; +2 – too humid. Frequency [%] Frequency [%]   EEPES-2022   IOP Publishing Journal of Physics: Conference Series 2339 (2022) 012024 doi:10.1088/1742-6596/2339/1/012024 In building "B", the students described the humidity as pleasant or quite dry in a percentage of about 42% and about 58%, respectively. Neither of them indicated that it was too humid or too dry. In the classroom at "Energis", unfortunately, as many as 54% of students thought that it was quite dry and about 31% that the room was too dry. Only 15% of the students marked the answer 0. In both rooms, the windows were closed during the examination, and the humidity was similar. The room in building "B" was much larger than that in "Energis", which could have had a significant impact on the assessment of both thermal and humidity sensations due to the fact the people need to have enough room to dissipate heat at a rate required by indoor conditions. It this is not possible, then people tend to experience negative sensations. No less important aspect is the insulating properties of the garment, which has a significant impact on determining thermal feelings. Therefore, figure 5 shows TSV and the insulation performance of students' clothing. -1 -2 -3 0,4 0,6 0,8 1,0 1,2 1,4 CLO Figure 5. Clothing insulation and TSV rating. According to the data in figure 5, there were as many as six people (two people had 0.63 clo) who, despite the low insulation properties of their clothing, described their thermal impressions as too warm. It should be mentioned that six of these people were in "Energis", so even the low resistance did not help to keep the body in balance. The clothing insulation capacity of the rest of the respondents was determined in the range of 0.5 - 1.3 clo. In this way, attention should be paid to the trend lines shown in figure 5. It has a downward tendency, which may mean that the individuality of each person may play an important role in this case. On the other hand, knowing the assessment of temperature and humidity, figure 6 with the results of Thermal Sensation Vote (calculated on the basis of the average of the survey responses) and Predicted Mean Vote (calculated on the basis of the ISO 7730 standard) is presented below. 1,4 TSV 1,2 PMV 1,0 0,8 0,6 0,4 0,2 0,0 -0,2 -0,4 -0,6 Smart building Traditional building Figure 6. Thermal Sensation Vote and Predicted Mean Vote for traditional and smart building. TSV/ PMV TSV   EEPES-2022   IOP Publishing Journal of Physics: Conference Series 2339 (2022) 012024 doi:10.1088/1742-6596/2339/1/012024 For the smart building, TSV was 1.31. This is a very high result far exceeding the norm. On the other hand, the PMV calculated from the standard was 0.42, which indicated that all standards of feeling comfort were met. The same result was obtained for TSV in the traditional building. Nevertheless, taking into account the PMV from the standard, the result is -0.60, exceeding the comfort range by 0.10. As mentioned earlier in the analysis of moisture, in the hall of the smart building, people were sitting next to each other and the room is smaller than in a traditional building. There, too, the students sat separately. Measurements were also not made from the very beginning, but in the middle of the class, so the air temperature in the room increased. It needs to be mentioned that the difference between the standard and the real experimental result has been reported in literature for the smart building [14]. It might also be related to the thermal insulation properties and the resulting conditions of indoor microclimate [15]. 4. Conclusions The analysis of the obtained results provided interesting thoughts and information on traditional and modern construction. It turned out that the smart building did not meet the thermal expectations of people who were too warm in it. Such reactions were also reflected in the very high TSV index. Based on the analysis, it was the traditional building that was defined as a comfortable room in which students feel good. These results could be influenced by the size of the room, the lack of open windows, the well-being of people and their clothing, and the content of carbon dioxide. Moreover, the relative humidity was assessed better by students in the building with 100% traditional buildings for the answers "pleasantly" and "quite dry" than in "Energis", where about 31% of people rated the humidity as "too dry". In addition, it was noticed that the clothing of people with even low insulation did not help to feel the microclimate comfortably. It should be mentioned that the differences between TSV and PMV from surveys and standards are very different from each other. In a room where the temperature was 26.7 C, people's feelings clearly show that such a temperature is uncomfortable, while for the guidelines in the standard, it turns out that all parameters meet the comfort criteria. The opposite situation is in building "B" where the temperature was 23.6 C, the students felt the thermal comfort, while the standard assumed that the microclimate parameters were not within the standard. The only way to better visualize people's actual thermal sensations according to the standard is to modify the formula. 5. References [1] Fanger P O 1974 Thermal Comfort, Arkady, Warsaw [2] ISO International Organisation for Standardization, Ergonomics of the thermal environment – Analytical determination and interpretation of thermal comfort using calculation of the PMV and PPD indices and local thermal comfort criteria, International Standard ISO 7730, (2005) [3] Dębska L and Krakowiak J 2021 Cold Climate HVAC & Energy (Tallin) vol 246 (Estonia) pp 1-7 https://doi.org/10.1051/e3sconf/202124615004 [4] Krawczyk N and Krakowiak J 2021 TE-RE-RD vol 286 (Romania) pp 1-11 https://doi.org/10.1051/e3sconf/202128602008 [5] Krawczyk N 2022 ICEGC 336 (Morocco) pp 1-6 https://doi.org/10.1051/e3sconf/ [6] Shin H, Kang M, Mun S H, Kwak Y and Huh J H 2021 Building and Environment vol 187 (Elsevier) https://doi.org/10.1016/j.buildenv.2020.107413 [7] Elnaklah R, Alnuaimi A, Alotaibi B S, Topriska E, Walker I and Natarajan S 2021 Building and Environment vol 200 (Elsevier) Szytula https://doi.org/10.1016/j.buildenv.2021.107899 [8] Hussaro K, Puangmalee N and Boonyayothin 2019 Journal of Renewable Energy and Smart Grid Technology 14 1 https://ph01.tci-thaijo.org/index.php/RAST/article/view/144191/ 6   EEPES-2022   IOP Publishing Journal of Physics: Conference Series 2339 (2022) 012024 doi:10.1088/1742-6596/2339/1/012024 [9] Yamtraipat N, Khedari J and Hirunlabh J 2005 Solar Energy 78 pp 504-517 https://doi.org/10.1016/j.solener.2004.07.006 [10] Dębska L 2021 Assessment of the indoor environment in the intelligent building (Civil and Environmental Engineering 17 pp 572-582 https://doi.org/10.2478/cee-2021-0058 [11] Mors S T, Hensen J L M, Loomans M G L C, Boerstra A C 2011 Building ana Environment 46, 2454 - 2461 https://doi.org/10.1016/j.buildenv.2011.05.025 [12] Enescu D, Valahia University of Targoviste, 2017 Renewable and Sustainable Energy Reviews 79 pp 1353 1379 http://dx.doi.org/10.1016/j.rser.2017.05.175 [13] Manu S, Shukla Y, Rawal R, Thomas L E, de Dear R., 2016 Building ana Environment 98 pp 55 - 70 https://doi.org/10.1016/j.buildenv.2015.12.019 [14] Majewski G, Telejko M and Orman Ł J 2017 E3S Web of Conferences 17, 00056 https://doi.org/10.1051/e3sconf/20171700056 [15] Piotrowski J Z, Orman Ł J, Lucas X, Zender – Świercz E, Telejko M and Koruba D 2014 EPJ Web of Conferences 67, 02095. https://doi.org/10.1051/epjconf/20146702095 http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png Journal of Physics: Conference Series IOP Publishing

Comparative analysis of thermal comfort in the traditional and smart buildings

Dębska, L
Journal of Physics: Conference Series , Volume 2339 (1): 7 – Sep 1, 2022
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EEPES-2022 IOP Publishing Journal of Physics: Conference Series 2339 (2022) 012024 doi:10.1088/1742-6596/2339/1/012024 Comparative analysis of thermal comfort in the traditional and smart buildings L Dębska Faculty of Environmental, Geomatic and Energy Engineering, Kielce University of Technology, Poland E-mail: [email protected] Abstract. All the constantly growing thermal requirements of people pose new challenges for designers in the field of modern and smart construction. The main idea of such buildings is to ensure the best possible conditions for the internal environment, especially in public facilities. In Poland, the majority of university buildings are traditional buildings that have been modernized, thus increasing the feeling of thermal comfort by people. The aim of this article is to conduct a comparative analysis of two rooms, for the smart building "Energis" and the traditional building "B" at the Kielce University of Technology. The testo 400 device was used to carry out the study, which, through parameters taken from the environment, enabled the calculation using the ISO 7730 standard, Predicted Mean Vote (PMV) and anonymous questionnaires from which an averaged Thermal Sensation Vote (TSV). The temperature of the o o first room was 26.7 C, and the temperature of the second was 23.6 C. The results turned out to be intriguing as the analysis showed that the students were not satisfied with the conditions in the smart building. 1. Introduction Thermal comfort is a state in which every person will not be too hot or too warm. The first studies that took into account thermal sensation were initiated by Fanger in the 1960s and 1970s. It was Fanger who created the formula that is used to this day in the ISO 7730 standard [1,2]. This formula is defined by an indicator such as Predicted Mean Vote (PMV), which indicates people's thermal sensation. For its calculations, it is necessary to know the internal parameters of the environment, such as air temperature, humidity, average temperature of radiation, air velocity, and clothing insulation. In addition, surveys are also carried out in which the respondents themselves determine how real they feel in the rooms. On the basis of the completed questionnaire, the average of the responses with the Thermal Sensation Vote (TSV) index. The knowledge of TSV and PMV for the tested objects enables the comparison of places that meet the thermal acceptance of people and the standard. In the literature review, a lot of research works related to TSV and PMV indicators. However, there is still almost no research (except for studies conducted by the author [3] and the other researchers from Kielce University of Technology [4,5] comparing modern construction with traditional construction. Shin et al. [6] analysed the PMV and TSV for CO in the university library, thus proposing a new air-conditioning solution that improves people's thermal sensations. The study found that as CO increased, people became hotter. Their thermal condition improved after the improvement of the air conditioning control unit. Elnaklah et al. [7] examined as many as 1101 people with 31 Content from this work may be used under the terms of the Creative Commons Attribution 3.0 licence. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI. Published under licence by IOP Publishing Ltd 1   EEPES-2022   IOP Publishing Journal of Physics: Conference Series 2339 (2022) 012024 doi:10.1088/1742-6596/2339/1/012024 buildings, including green construction in four countries. Despite the fact that 58% of the given internal parameters were within the norm, for 40% of the respondents they were only acceptable. Additionally, the respondents described their feelings during the summer as too overcooled, feeling discomfort in this connection. What is more, Hussaro et al. [8] from Thailand studied students, checking the extent of their thermal comfort and reducing the consumption of the energy sector used to supply air conditioning. Measurements were made from the temperature of 25-28 C, at various air velocities, from 0.5-0.9 m / s. The results provided information that a set temperature of around 25 C degrees could be changed to 26-28 C while increasing air velocity in the room and thus reducing energy costs by around 7.30% when the temperature is raised by 1 C. In addition, the authors of the work [9], also from Thailand, obtained similar results, in which the analysis determined similar parameters of thermal compartment at 26 C at 50-60% humidity. In a smart building, the author of the work [10] checked how women and men felt thermal comfort. 164 people were examined, including 97 men and 67 women for the temperature range from 19.3 C to 27.6 C. It turned out that the TSV of women and men was a feeling of comfort, but the women felt more cold, and the men felt too warm. Moreover, Mors et al. [11] focused on the thermal sensations of children aged 9 to 11 in rooms that could not be air-conditioned in the Netherlands. The research period covered winter, spring and summer. According to the questionnaires, the insulation of clothing according to children was 0.9 clo for the winter period and 0.3 clo for the summer period. Significant differences have been observed between TSV and PMV, reporting that PMV is not able to actually determine the real thermal sensation of students. Also, the PMV index has been analysed by the authors [12,13]. This work will focus on the comparison of two educational buildings - smart building and traditional building, analysing thermal comfort using the TSV and PMV indicators. 2. Materials and methods In April (spring conditions in Poland), thermal comfort tests were carried out to compare thermal sensations in the traditional "B" building and in the smart "Energis" building belonging to the Kielce University of Technology. The first one was built in the 1960s. Its modernization was carried out 10 years ago. The second building under study, "Energis", was built in 2012. It uses all kinds of renewable energy sources (heat pumps, wind turbine, etc.) to be energy independent and the Building Manager System is responsible for regulating lighting during the day and night, as well as energy produced and consumed. Both examined buildings are shown in figure 1. a) b) Figure 1. Photos of the buildings covered by the study: a) traditional building called "B" and b) smart building called "Energis". 2 EEPES-2022 IOP Publishing Journal of Physics: Conference Series 2339 (2022) 012024 doi:10.1088/1742-6596/2339/1/012024 For both tested objects, two the same measurement methods were used with the participation of students completing the questionnaires determining thermal sensations and with the use of the Testo 400 environmental meter. In the first method, the respondents were asked to describe their feelings in terms of temperature or humidity, and thermal preferences. The questionnaires provide information about the health and physical activity of the surveyed people. The patient's illness may cause the temperature to feel cooler, and the person who was running on the treadmill before coming to the test, will have a higher heart rate, which will cause a false image of their thermal sensations. Moreover, the questionnaire helps to determine the insulating power of the clothing called "clo" of the respondents and to calculate the Body Mass Index "BMI". The second method is based on an environmental gauge which takes internal parameters such as air temperature, humidity, light intensity, carbon dioxide or air velocity from the tested environment. Obtaining these data enables the calculation of the formula for PMV from the ISO 7730 standard. The measurement itself lasted over 15 minutes so that all data stabilized. After this time, the results were saved. In total, 25 people participated in the study. In "Energis" 13 people were examined, where men constituted the majority of the studied group, equal to 62%, and women - 38%. In contrast, in the traditional building "B", the study covered 12 people, where women only constituted 17% of the respondents, and men 83%. The age range for both groups was 21 to 52 years old (one teacher). The rooms under study are situated towards the west. The "Energis" is on the second floor, and in the "B" building, it is on the fourth floor. The study was conducted on the same day, at a similar time. Figure 2 shows the tested room in building "B" with a measuring station. Figure 2. A classroom with a microclimate meter. 3. Results and discussion The obtained parameters of the internal environment are summarized in table 1. Table 1. Comparison of parameters from the tested rooms. Air Temperature Carbion Air Speed Black Ball Relative o o ( C) Dioxide (ppm) (m/s) Sphere ( C) Humidity (%) Traditional 23.6 660 0.06 23.7 26.29 building “B” Smart building 26.7 1453 0.07 26.3 29.13 “Energis” 3   EEPES-2022   IOP Publishing Journal of Physics: Conference Series 2339 (2022) 012024 doi:10.1088/1742-6596/2339/1/012024 The biggest differences can be seen between the air temperature, which was 3.1 C, and thus between the black sphere temperature, equal to 2.6 C, and the concentration of carbon dioxide, which was twice as high in the "Energis" room. Additionally, the average thermal resistance of clothing of 0.68clo for both studies was used for the calculations. The respondents described their feelings according to a seven-point scale from -3 to +3, where -3 describes the temperature as too cold and +3 describes the temperature as too hot. Figure 3 presents a summary of the TSV results obtained for two rooms. Traditional building B Smart building Energis -3 -2 -1 0 1 2 3 TSV Figure 3. Respondents' answers describing their current thermal sensation (TSV) for building "B" and "Energis": -3 – too cold; -2 – too cool; -1 – pleasantly cool; 0 – comfortable; +1 – pleasantly warm; +2 – too warm; +3 – too hot. Figure 3 shows that people studying in a classroom located in a traditional building felt thermal comfort by selecting answers 0 and 1. Contrary to the classroom in "Energis", where as many as 46% of people found the room temperature too warm. Thus, all the room users in the traditional building accepted the environment, while for almost half of the people in “Energis” is was beyond the acceptable TSV range of -1 to +1. It is definitely delated to higher temperature in Energis of almost 27 C. Besides the high carbon dioxide level there might be responsible for such thermal sensations. Naturally, it also indicates poor air exchange and ventilation problems. No less important factor that people feel is relative humidity. The respondents' assessment of humidity is shown in figure 4. Traditional building B Smart building Energis -2 -1 0 1 2 AHV Figure 4. Relative humidity assessed by students: -2 – too dry; -1 – quite dry; 0 – pleasantly; +1 – quite humid; +2 – too humid. Frequency [%] Frequency [%]   EEPES-2022   IOP Publishing Journal of Physics: Conference Series 2339 (2022) 012024 doi:10.1088/1742-6596/2339/1/012024 In building "B", the students described the humidity as pleasant or quite dry in a percentage of about 42% and about 58%, respectively. Neither of them indicated that it was too humid or too dry. In the classroom at "Energis", unfortunately, as many as 54% of students thought that it was quite dry and about 31% that the room was too dry. Only 15% of the students marked the answer 0. In both rooms, the windows were closed during the examination, and the humidity was similar. The room in building "B" was much larger than that in "Energis", which could have had a significant impact on the assessment of both thermal and humidity sensations due to the fact the people need to have enough room to dissipate heat at a rate required by indoor conditions. It this is not possible, then people tend to experience negative sensations. No less important aspect is the insulating properties of the garment, which has a significant impact on determining thermal feelings. Therefore, figure 5 shows TSV and the insulation performance of students' clothing. -1 -2 -3 0,4 0,6 0,8 1,0 1,2 1,4 CLO Figure 5. Clothing insulation and TSV rating. According to the data in figure 5, there were as many as six people (two people had 0.63 clo) who, despite the low insulation properties of their clothing, described their thermal impressions as too warm. It should be mentioned that six of these people were in "Energis", so even the low resistance did not help to keep the body in balance. The clothing insulation capacity of the rest of the respondents was determined in the range of 0.5 - 1.3 clo. In this way, attention should be paid to the trend lines shown in figure 5. It has a downward tendency, which may mean that the individuality of each person may play an important role in this case. On the other hand, knowing the assessment of temperature and humidity, figure 6 with the results of Thermal Sensation Vote (calculated on the basis of the average of the survey responses) and Predicted Mean Vote (calculated on the basis of the ISO 7730 standard) is presented below. 1,4 TSV 1,2 PMV 1,0 0,8 0,6 0,4 0,2 0,0 -0,2 -0,4 -0,6 Smart building Traditional building Figure 6. Thermal Sensation Vote and Predicted Mean Vote for traditional and smart building. TSV/ PMV TSV   EEPES-2022   IOP Publishing Journal of Physics: Conference Series 2339 (2022) 012024 doi:10.1088/1742-6596/2339/1/012024 For the smart building, TSV was 1.31. This is a very high result far exceeding the norm. On the other hand, the PMV calculated from the standard was 0.42, which indicated that all standards of feeling comfort were met. The same result was obtained for TSV in the traditional building. Nevertheless, taking into account the PMV from the standard, the result is -0.60, exceeding the comfort range by 0.10. As mentioned earlier in the analysis of moisture, in the hall of the smart building, people were sitting next to each other and the room is smaller than in a traditional building. There, too, the students sat separately. Measurements were also not made from the very beginning, but in the middle of the class, so the air temperature in the room increased. It needs to be mentioned that the difference between the standard and the real experimental result has been reported in literature for the smart building [14]. It might also be related to the thermal insulation properties and the resulting conditions of indoor microclimate [15]. 4. Conclusions The analysis of the obtained results provided interesting thoughts and information on traditional and modern construction. It turned out that the smart building did not meet the thermal expectations of people who were too warm in it. Such reactions were also reflected in the very high TSV index. Based on the analysis, it was the traditional building that was defined as a comfortable room in which students feel good. These results could be influenced by the size of the room, the lack of open windows, the well-being of people and their clothing, and the content of carbon dioxide. Moreover, the relative humidity was assessed better by students in the building with 100% traditional buildings for the answers "pleasantly" and "quite dry" than in "Energis", where about 31% of people rated the humidity as "too dry". In addition, it was noticed that the clothing of people with even low insulation did not help to feel the microclimate comfortably. It should be mentioned that the differences between TSV and PMV from surveys and standards are very different from each other. In a room where the temperature was 26.7 C, people's feelings clearly show that such a temperature is uncomfortable, while for the guidelines in the standard, it turns out that all parameters meet the comfort criteria. The opposite situation is in building "B" where the temperature was 23.6 C, the students felt the thermal comfort, while the standard assumed that the microclimate parameters were not within the standard. The only way to better visualize people's actual thermal sensations according to the standard is to modify the formula. 5. 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Journal of Physics: Conference Series – IOP Publishing

Published: Sep 1, 2022

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