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One-year Field Study on Indoor Environment of Huizhou Traditional Vernacular Dwellings in China
Available online at www.sciencedirect.com
ScienceDirect
Available online at www.sciencedirect.com Procedia Engineering 00 (2017) 000–000
ScienceDirect
www.elsevier.com/locate/procedia
Procedia Engineering 205 (2017) 1316–1322
10th International Symposium on Heating, Ventilation and Air Conditioning, ISHVAC2017, 1922 October 2017, Jinan, China
One-year Field Study on Indoor Environment of Huizhou Traditional Vernacular Dwellings in China Zhijia Huang*, Mengqi Yu, Liangji Zheng, Cheng Gong, Zhouqin Wu School of Civil Engineering and Architecture, Anhui University of Technology, Ma'anshan, China
Abstract To create a comfortable indoor environment is the main development direction of the current architecture based on energy conservation, which has aroused a great interest in passive design strategies of traditional vernacular dwellings. This study conducted a field measurement in a typical traditional vernacular dwelling in Huizhou to investigate the building performance. On the basis of the monitored indoor and outdoor environment parameters by auto-recorders, one-year evaluation is obtained in terms of four aspects, i.e. thermal environment, visual environment, acoustic environment and thermal comfort. Results show that the dwelling has a good indoor environment and thermal comfort in spring and autumn. The indoor thermal comfort is also good during summer due to good natural ventilation and sun shading. However, the indoor thermal comfort is not fully satisfactory during winter due to the poor air tightness, and the indoor relative humidity is relative high all the year round. The acoustic environment is found to comply with relevant standards for all the rooms. The daylight of living room and bedroom is mainly depending on the patio, which leads to insufficient visual environment as required for some time. © 2017 The Authors. Published by Elsevier Ltd. © 2017 The under Authors. Published by Ltd. committee of the 10th International Symposium on Heating, Ventilation and Air Peer-review responsibility of Elsevier the scientific Peer-review under responsibility of the scientific committee of the 10th International Symposium on Heating, Ventilation and Conditioning. Air Conditioning. Keywords: Huizhou traditional vernacular dwellings; Thermal environment; Visual environment; Acoustic environment; Field measurement
1. INTRODUCTION It is commonly acknowledged that a comfortable indoor environment is a key issue for residential energy
* Corresponding author. Tel.: 13155538549; fax: 0555-2316522. E-mail address: [email protected] 1877-7058 © 2017 The Authors. Published by Elsevier Ltd. Peer-review under responsibility of the scientific committee of the 10th International Symposium on Heating, Ventilation and Air Conditioning.
1877-7058 © 2017 The Authors. Published by Elsevier Ltd. Peer-review under responsibility of the scientific committee of the 10th International Symposium on Heating, Ventilation and Air Conditioning. 10.1016/j.proeng.2017.10.092
2
Zhijia Huang et al. / Procedia Engineering 205 (2017) 1316–1322 Author name / Procedia Engineering 00 (2017) 000–000
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conservation and sustainable development in rural areas [1]. The application of passive design strategies is an fundamental approach to provide thermal comfort and reduce the need of active devices to minimize the building energy demand. Consequently, passive design strategies are widely integrated in the traditional vernacular dwellings all over the world [2-3]. Despite the regional diversity, numbers of studies have revealed that the traditional vernacular dwellings are the picture built by local people using locally available material/resources and adaptive climate to deal with the indoor comfort [4-5]. In China, there are rich academic achievements on indoor environment of traditional vernacular dwellings in northwest region of China [6-7]. Some recent studies on traditional vernacular dwellings of south China concluded that it has strongly special local characteristics and a good natural ventilation is one of key elements to enhance indoor thermal environment [8-9]. For a specific geographical region of China that is characterized by hot summer and cold winter conditions, a few researchers [10-11] found that the traditional vernacular dwellings has an effective sunshading and insulation in summertime due to the building layout and wall construction. The indoor thermal comfort, however, is not fully satisfactory during winter. Improvement of indoor thermal comfort and the ventilation potential of patio are paid great attention for a better understanding of the traditional vernacular dwellings. The existing studies on traditional dwellings are mainly focused on thermal environment, and a comprehensive performance evaluation considering visual and acoustic environment is still lacking. Therefore, this study conducts a detailed field measurement on a typical traditional vernacular dwelling in Huizhou, and the indoor and outdoor environment parameters, i.e. temperature, relative humidity, SPL (sound pressure level) and illumination, are monitored by auto-recorders for one year. The indoor environment characteristics are then evaluated in terms of thermal environment, visual environment, acoustic environment and thermal comfort. 2. OUTLINE OF THE MEASUREMENTS 2.1. Description of the studied dwellings - Yuqing House The studied dwelling, named Yuqing House, is located in the village of Zhaji in Huizhou area. As Huizhou is located in the southwest region of the Anhui province in China, it belongs to the subtropical monsoon climatic. Huizhou traditional dwellings are still in original form without any alterations over time and have indigenous people living here. Yuqing House is oriented north to south, and it is a two-story dwellings combing with an internal courtyard. The total area is appropriately 410m2. The first floor consists of a kitchen, two living rooms, four bedrooms and two store rooms. In addition, the living room is directly connect to the patio, as shown in Fig.1(a). The second floor is attics which are currently used as store rooms. The passive design strategies of Yuqing House are effective in creating the pleasant microclimate due to its village location, building layout, the openings of building (Fig.1(b)). What’s more, the materials used in Yuqing House are primarily obtained from locally abundant and easily obtainable natural resources.
a. Living room and patio b. Bedroom and its hollowing windows Fig.1. Indoor view of the dwelling considered in this study
Zhijia Huang et al. / Procedia Engineering 205 (2017) 1316–1322 Author name / Procedia Engineering 00 (2017) 000–000
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2.2. Experiment setup Field measurement was mainly focused on the first floor, since it is the main part of the house originally occupied by the house owners. The measurements were conducted from July 14, 2015 to September 1, 2016. In this study, the building performance is evaluated by dividing the whole year into four seasons (Spring: March to May; Summer: June to August, Autumn: September to November, Winter: December to February of next year). Table.1. shows the instruments used for collecting the corresponding parameters. The filled circles, as shown in Fig.2, show where the temperature and relative humidity were measured. All measured points were set at 1.5m above the ground level. The outdoor data loggers were shaded using appropriate devices during the whole measurement. It is noted that the points of sound pressure level (SPL) and illumination are not shown in Fig.2, as they were evenly distributed in the each room of dwellings. SPL (18 points) and illumination (61 points) were measured by manual recording which was set at 0.75m above the ground level.
Fig.2. Data monitoring locations in Yuqing House Table.1. Measured parameters and instruments Measured parameter
Instrument
Precision
Measured time
Note
Temperature
TR-72wf Temp/RH data logger
±0.3°C
2015.9.1-2016.9.1
Auto acqusition per 15min
Relative humidity
TR-72wf Temp/RH data logger
±5.0%RH
2015.9.1-2016.9.1
Auto acqusition per 15min
SPL
TES-1350A Sound level meter
±2dB
2015.7.14
Manual acqusition per 30min
Illumination
TES-1336A data logging Light meter
±（3%rdg+5dgts）
2016.1.26
Manual acqusition per 30min
3. RESULTS AND ANALYSIS 3.1. Indoor temperature Fig.3. shows the temperatures of different measured points for four seasons. In summer, outdoor temperature is the most fluctuating one among the four measured points, with the variation between 41.6℃and 18.2℃. The patio, acting as a transition space which can reduce the effect of outdoor temperature fluctuation, has a lower maximum
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temperature (4.2℃) than that of outdoor. The temperatures of living room and bedroom are much stable with the average temperatures of 26.3℃ and 25.7℃respectively, which is mainly resulting from interactions among the patio, building layout and sun shading. In winter, the outdoor temperature is varied between -10.9℃to 25.2℃ with an average temperature of 5.2℃. The average temperature of living room is relatively low, which may be caused by the patio that connects the living room and outdoor. The bedroom is slightly warmer with an average temperature 7.1℃, but it still can’t satisfy indoor thermal standard. In the Huizhou traditional vernacular dwellings, the hollowing windows of bedrooms, which are made up of timber, may also cause the heat loss due to the poor air tightness. Therefore, the indoor thermal environment is not comfortable and need to be improved in winter. For the mild season (spring and autumn), outdoor temperature is varied from -0.6℃ to 34.8℃, and the average temperature of outdoor, patio, living room and bedroom is 17.5℃, 17.0℃, 17.2℃, 16.4℃ respectively. The indoor environment can be benefit from the patio due to its natural ventilation during this period. 45 40
Temperature/℃
35 30 25
MAX
20
AVE
15
MIN
10 5 0 -5
-10 -15
Spring
Summer Outdoor
Autumn
Mild season Patio
Living room
Winter Bedroom
Fig.3. Temperature at different points during four seasons
3.2. Indoor relative humidity 100
Relative humidity/%
90 80 70
MAX
60
AVE
50
MIN
40 30 20 10 0
Spring Summer Outdoor
Autumn
Mild season Patio
Living room
Winter Bedroom
Fig.4. Relative humidity at different points during four seasons
Fig.4. shows the results of indoor/outdoor relative humidity in four seasons. In all seasons, the maximum relative
Zhijia Huang et al. / Procedia Engineering 205 (2017) 1316–1322 Author name / Procedia Engineering 00 (2017) 000–000
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humidity of outdoor and indoor can reach 100%, and the average relative humidity of the four measured points (i.e. outdoor, patio, living room and bedroom) is above 75% in four seasons. It is found that the outdoor has a minimum relative humidity above 30% in summer, which is the highest one among the seasons. Both the living room and bedroom has a concentrated distribution of relative humidity, which is fluctuated between 60.0%~95.0%. In addition, the average indoor relative humidity is higher than that of outdoor, and it is a little higher in the bedroom (about 83.1%) than that in living room (about 80.0%). The lower relative humidity of living room may be caused by the patio that taking the humid air outside. 3.3. Thermal comfort In this study, the thermal comfort is evaluated using the temperature and relative humidity. Local people have a comparatively higher adaptability in Huizhou area since the vernacular dwellings are designed without air conditioning. Thus, the comfort zone [12] for indoor environment has been expanded in different seasons due to the use of ventilation [13] and solar radiation. Fig.5. shows the comfort zones of the bedroom for one year, which divided by three seasons: summer, mild season (spring and autumn) and winter. It is noted that the evaluation is made for the night (from 20:00 to 6:00 of the next day) of the whole year. It is found that 62.2% of summer time is comfortable and 6.9% of summer time is out of the comfort zone due to the high temperature. And the left 30.8% of summer time in beyond the comfort zone because of the damp. For mild season (spring and autumn), about 90.2% of time is comfortable, there are still 1.3% and 8.5% of time in beyond the comfort zone due to cold and damp respectively. However, there is only 8.9% of winter time in the comfort zone while most of the winter times is outside the comfort zone due to the low temperature and a few time due to the damp. It can be concluded that the traditional dwellings adapt well to the summer and mild season, but it has a poor indoor thermal comfort in winter.
80%
25
60%
fo
rt
zo n
e
20
40%
se as o
n
co m
15 10
M ild
Humidity ratio/(g/kg)
30
Summer comfort zone
5 0
20%
Winter comfort zone
-5
0
5
10 15 20 25 Temperature/℃
Mild season
Summer
30
35
40
Winter
Fig.5. Comfort zone of each season
3.4. Acoustic environment In order to investigate the performance of acoustic environment in Yuqing House, the measured sound pressures at different times are imported into MATLAB and then formed the SPL field cloud, as shown in Fig. 6(a-d). The SPL range of the dwelling is found to between 45dB(A) and 70dB(A). It is found that the SPL field cloud at 10:00 is similar to that at 14:00, which has a maximum SPL of 70dB(A) at the living room and outdoor due to human frequent activities, the average SPL of indoor is about 54 dB(A). At the time of 16:00 (c), a high sound pressure is found to extend at the outdoor which may caused by local people activity habits. By contrast, the SPL of both outdoor and indoor is decreased until at 18:00 (d) except the living room with the SPL reaching 65dB(A). It can be
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concluded that Huizhou vernacular dwellings has a well acoustic environment that can meet the acoustic standard of China. This is mainly benefited from the enclosed building forms and high external walls of these dwellings with no windows, which can greatly reduce the noise from the outdoor. On the other hand, the front and back patios also play a role of “sound lock” to keep away from the noise of outdoor.
a.10:00 b.14:00 c.16:00 d.18:00 Fig.6. SPL field cloud of indoor and outdoor
3.5. Visual environment
a.10:00 b.14:00 c.18:00 Fig.7. The illumination field cloud of indoor and outdoor
The patio has the function of day lighting and ventilation for buildings, thus it has a great impact on the indoor visual environment. In this study, the illumination was measured for a sunny day and then imported into MATLAB to form the illumination field cloud, as shown in Fig.7(a-d). At the time of 10:00(a), the maximum illumination of north wall can reach 200lux, and the illumination of bedrooms is lower than 50lux. It is found that the illumination of indoor is increased greatly at 14:00(b), e.g. the patio, living room, and the door near of bedroom can reach 600lux, 350lux, 200lux respectively. By contrast, the illumination of indoor is decreased largely at 18:00(c) except the front door with the illumination reaching 80lux. It can be concluded that the illumination variation of the living room is synchronized with that of the patio. It indicates that a high illumination can be obtained for the living room during daytime as it is directly connected to the patio. However, illumination variation of the bedroom is below 20lux which can’t comply with the suggested illumination of 300lux. This may be caused by the high external walls of Huizhou traditional vernacular dwellings without windows. 4. CONCLUSION (1) The characteristic of cold winter and cool summer in Huizhou traditional vernacular dwellings is demonstrated by one year measured data. The cool summer, which means indoor thermal comfort is good due to the compact building layout, high external wall and transition space such as patio which contributes to the sun shading
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and natural ventilation. Meanwhile, it shows that the dwelling has a good indoor environment and thermal comfort in spring and autumn. However, the indoor thermal environment is not really well for most of winter time, which is suggested to be improved by space heating. (2) The acoustic environment is complying with relevant standards for most of the rooms in Huizhou traditional vernacular dwelling, which mainly benefited from the enclosed building forms, high external walls with no windows of Huizhou traditional vernacular dwellings. (3) The daylight of living room and bedroom is mainly depending on the patio, which leads to insufficient visual environment some time and can’t satisfy the requirement of relevant standards. The main reason for that may be the high external walls without windows in Huizhou traditional vernacular dwellings. Acknowledgements This work is supported by the National Natural Science Foundation of China (No. 51478001) and the Student Research Training Program of China (No. 201710360045). The authors would like to sincerely thank the individuals who provided suggestions and comments during this study. References [1] M.J. Holmes, J.N. Hacker. Climate change thermal comfort and energy: meeting the design challenges of the 21st century, Energy and Buildings, 39(2007)802-814. [2] D.K. Kim. The natural environment control system of Korean traditional architecture: Comparison with Korean contemporary architecture, Building and Environment, 41(2006)1905-1912. [3] M. Baran, M. Yildirim, A. Yilmaz. Evaluation of ecological design strategies in traditional houses in Diyarbakir in Turkey, Journal of Cleaner Production, 19(2011)609-619. [4] M.K. Nematchoua, R. Tchinda , J.A. Orosa. Thermal comfort and energy consumption in modern versus traditional buildings in Cameroon: a questionnaire-based statistical study, Applied Energy, 114(2014)687–699. [5] R. Ooka. Field study on sustainable indoor climate design of a Japanese traditional folk house in cold climate area, Building and Environment, 37 (2002)319-329. [6] W.F. He, L. Yang, J.P. Liu. Climate adaptability development of Qinling mountains traditional dwellings, Architectural Journal, (2009)2426.(in Chinese) [7] X.R. Zhu , J.P. Liu, R.R. Hu. Energy performance of a new Yaodong dwelling, in the Loess Plateau of China. Energy and Buildings, 70(2014)159–166. [8] L. Jin, L.H. Zhao, Y.F. Zhang. Field study and modern enlightenment on thermal environment of traditional vernacular dwellings in Chaoshan area, Building Science, 30(6)(2014)27-31.(in Chinese) [9] X.Y. Chen, J.W. Xue, B Zheng. Field study on thermal environment of Quanzhou traditional Shoujinliao residence in summer, Architectural Journal, (2010)85-87.(in Chinese) [10] B.R. Lin, G.G. Tan, P Wang. Study on the thermal performance of the Chinese traditional vernacular dwellings in Summer, Energy and Buildings, 36(2004)73-79. [11] B. Song, L Yang, D.L. Liu. Field study on indoor thermal environment in Huizhou traditional residence in Xidi in winter, Architecture Technology, 45(11)(2014)1033-1036.(in Chinese) [12] E.Arens, L.Zeren, R.Gonzalez.et al. 1980 A new bioclimatic chart for environment design. Building Energy Management, Conventional and Solar Approaches, Proceeding of the international congress, Potugal. [13] M.L. Tan, B.Z. Li, W.J. Li, et al. Physiological Experiment for Human Thermal Comfort of Air Flow in Summer, Journal of Civil, Architectural＆Environmental Engineering, 33(2)(2011)70-73.(in Chinese)
ScienceDirect
Available online at www.sciencedirect.com Procedia Engineering 00 (2017) 000–000
ScienceDirect
www.elsevier.com/locate/procedia
Procedia Engineering 205 (2017) 1316–1322
10th International Symposium on Heating, Ventilation and Air Conditioning, ISHVAC2017, 1922 October 2017, Jinan, China
One-year Field Study on Indoor Environment of Huizhou Traditional Vernacular Dwellings in China Zhijia Huang*, Mengqi Yu, Liangji Zheng, Cheng Gong, Zhouqin Wu School of Civil Engineering and Architecture, Anhui University of Technology, Ma'anshan, China
Abstract To create a comfortable indoor environment is the main development direction of the current architecture based on energy conservation, which has aroused a great interest in passive design strategies of traditional vernacular dwellings. This study conducted a field measurement in a typical traditional vernacular dwelling in Huizhou to investigate the building performance. On the basis of the monitored indoor and outdoor environment parameters by auto-recorders, one-year evaluation is obtained in terms of four aspects, i.e. thermal environment, visual environment, acoustic environment and thermal comfort. Results show that the dwelling has a good indoor environment and thermal comfort in spring and autumn. The indoor thermal comfort is also good during summer due to good natural ventilation and sun shading. However, the indoor thermal comfort is not fully satisfactory during winter due to the poor air tightness, and the indoor relative humidity is relative high all the year round. The acoustic environment is found to comply with relevant standards for all the rooms. The daylight of living room and bedroom is mainly depending on the patio, which leads to insufficient visual environment as required for some time. © 2017 The Authors. Published by Elsevier Ltd. © 2017 The under Authors. Published by Ltd. committee of the 10th International Symposium on Heating, Ventilation and Air Peer-review responsibility of Elsevier the scientific Peer-review under responsibility of the scientific committee of the 10th International Symposium on Heating, Ventilation and Conditioning. Air Conditioning. Keywords: Huizhou traditional vernacular dwellings; Thermal environment; Visual environment; Acoustic environment; Field measurement
1. INTRODUCTION It is commonly acknowledged that a comfortable indoor environment is a key issue for residential energy
* Corresponding author. Tel.: 13155538549; fax: 0555-2316522. E-mail address: [email protected] 1877-7058 © 2017 The Authors. Published by Elsevier Ltd. Peer-review under responsibility of the scientific committee of the 10th International Symposium on Heating, Ventilation and Air Conditioning.
1877-7058 © 2017 The Authors. Published by Elsevier Ltd. Peer-review under responsibility of the scientific committee of the 10th International Symposium on Heating, Ventilation and Air Conditioning. 10.1016/j.proeng.2017.10.092
2
Zhijia Huang et al. / Procedia Engineering 205 (2017) 1316–1322 Author name / Procedia Engineering 00 (2017) 000–000
1317
conservation and sustainable development in rural areas [1]. The application of passive design strategies is an fundamental approach to provide thermal comfort and reduce the need of active devices to minimize the building energy demand. Consequently, passive design strategies are widely integrated in the traditional vernacular dwellings all over the world [2-3]. Despite the regional diversity, numbers of studies have revealed that the traditional vernacular dwellings are the picture built by local people using locally available material/resources and adaptive climate to deal with the indoor comfort [4-5]. In China, there are rich academic achievements on indoor environment of traditional vernacular dwellings in northwest region of China [6-7]. Some recent studies on traditional vernacular dwellings of south China concluded that it has strongly special local characteristics and a good natural ventilation is one of key elements to enhance indoor thermal environment [8-9]. For a specific geographical region of China that is characterized by hot summer and cold winter conditions, a few researchers [10-11] found that the traditional vernacular dwellings has an effective sunshading and insulation in summertime due to the building layout and wall construction. The indoor thermal comfort, however, is not fully satisfactory during winter. Improvement of indoor thermal comfort and the ventilation potential of patio are paid great attention for a better understanding of the traditional vernacular dwellings. The existing studies on traditional dwellings are mainly focused on thermal environment, and a comprehensive performance evaluation considering visual and acoustic environment is still lacking. Therefore, this study conducts a detailed field measurement on a typical traditional vernacular dwelling in Huizhou, and the indoor and outdoor environment parameters, i.e. temperature, relative humidity, SPL (sound pressure level) and illumination, are monitored by auto-recorders for one year. The indoor environment characteristics are then evaluated in terms of thermal environment, visual environment, acoustic environment and thermal comfort. 2. OUTLINE OF THE MEASUREMENTS 2.1. Description of the studied dwellings - Yuqing House The studied dwelling, named Yuqing House, is located in the village of Zhaji in Huizhou area. As Huizhou is located in the southwest region of the Anhui province in China, it belongs to the subtropical monsoon climatic. Huizhou traditional dwellings are still in original form without any alterations over time and have indigenous people living here. Yuqing House is oriented north to south, and it is a two-story dwellings combing with an internal courtyard. The total area is appropriately 410m2. The first floor consists of a kitchen, two living rooms, four bedrooms and two store rooms. In addition, the living room is directly connect to the patio, as shown in Fig.1(a). The second floor is attics which are currently used as store rooms. The passive design strategies of Yuqing House are effective in creating the pleasant microclimate due to its village location, building layout, the openings of building (Fig.1(b)). What’s more, the materials used in Yuqing House are primarily obtained from locally abundant and easily obtainable natural resources.
a. Living room and patio b. Bedroom and its hollowing windows Fig.1. Indoor view of the dwelling considered in this study
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2.2. Experiment setup Field measurement was mainly focused on the first floor, since it is the main part of the house originally occupied by the house owners. The measurements were conducted from July 14, 2015 to September 1, 2016. In this study, the building performance is evaluated by dividing the whole year into four seasons (Spring: March to May; Summer: June to August, Autumn: September to November, Winter: December to February of next year). Table.1. shows the instruments used for collecting the corresponding parameters. The filled circles, as shown in Fig.2, show where the temperature and relative humidity were measured. All measured points were set at 1.5m above the ground level. The outdoor data loggers were shaded using appropriate devices during the whole measurement. It is noted that the points of sound pressure level (SPL) and illumination are not shown in Fig.2, as they were evenly distributed in the each room of dwellings. SPL (18 points) and illumination (61 points) were measured by manual recording which was set at 0.75m above the ground level.
Fig.2. Data monitoring locations in Yuqing House Table.1. Measured parameters and instruments Measured parameter
Instrument
Precision
Measured time
Note
Temperature
TR-72wf Temp/RH data logger
±0.3°C
2015.9.1-2016.9.1
Auto acqusition per 15min
Relative humidity
TR-72wf Temp/RH data logger
±5.0%RH
2015.9.1-2016.9.1
Auto acqusition per 15min
SPL
TES-1350A Sound level meter
±2dB
2015.7.14
Manual acqusition per 30min
Illumination
TES-1336A data logging Light meter
±（3%rdg+5dgts）
2016.1.26
Manual acqusition per 30min
3. RESULTS AND ANALYSIS 3.1. Indoor temperature Fig.3. shows the temperatures of different measured points for four seasons. In summer, outdoor temperature is the most fluctuating one among the four measured points, with the variation between 41.6℃and 18.2℃. The patio, acting as a transition space which can reduce the effect of outdoor temperature fluctuation, has a lower maximum
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temperature (4.2℃) than that of outdoor. The temperatures of living room and bedroom are much stable with the average temperatures of 26.3℃ and 25.7℃respectively, which is mainly resulting from interactions among the patio, building layout and sun shading. In winter, the outdoor temperature is varied between -10.9℃to 25.2℃ with an average temperature of 5.2℃. The average temperature of living room is relatively low, which may be caused by the patio that connects the living room and outdoor. The bedroom is slightly warmer with an average temperature 7.1℃, but it still can’t satisfy indoor thermal standard. In the Huizhou traditional vernacular dwellings, the hollowing windows of bedrooms, which are made up of timber, may also cause the heat loss due to the poor air tightness. Therefore, the indoor thermal environment is not comfortable and need to be improved in winter. For the mild season (spring and autumn), outdoor temperature is varied from -0.6℃ to 34.8℃, and the average temperature of outdoor, patio, living room and bedroom is 17.5℃, 17.0℃, 17.2℃, 16.4℃ respectively. The indoor environment can be benefit from the patio due to its natural ventilation during this period. 45 40
Temperature/℃
35 30 25
MAX
20
AVE
15
MIN
10 5 0 -5
-10 -15
Spring
Summer Outdoor
Autumn
Mild season Patio
Living room
Winter Bedroom
Fig.3. Temperature at different points during four seasons
3.2. Indoor relative humidity 100
Relative humidity/%
90 80 70
MAX
60
AVE
50
MIN
40 30 20 10 0
Spring Summer Outdoor
Autumn
Mild season Patio
Living room
Winter Bedroom
Fig.4. Relative humidity at different points during four seasons
Fig.4. shows the results of indoor/outdoor relative humidity in four seasons. In all seasons, the maximum relative
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humidity of outdoor and indoor can reach 100%, and the average relative humidity of the four measured points (i.e. outdoor, patio, living room and bedroom) is above 75% in four seasons. It is found that the outdoor has a minimum relative humidity above 30% in summer, which is the highest one among the seasons. Both the living room and bedroom has a concentrated distribution of relative humidity, which is fluctuated between 60.0%~95.0%. In addition, the average indoor relative humidity is higher than that of outdoor, and it is a little higher in the bedroom (about 83.1%) than that in living room (about 80.0%). The lower relative humidity of living room may be caused by the patio that taking the humid air outside. 3.3. Thermal comfort In this study, the thermal comfort is evaluated using the temperature and relative humidity. Local people have a comparatively higher adaptability in Huizhou area since the vernacular dwellings are designed without air conditioning. Thus, the comfort zone [12] for indoor environment has been expanded in different seasons due to the use of ventilation [13] and solar radiation. Fig.5. shows the comfort zones of the bedroom for one year, which divided by three seasons: summer, mild season (spring and autumn) and winter. It is noted that the evaluation is made for the night (from 20:00 to 6:00 of the next day) of the whole year. It is found that 62.2% of summer time is comfortable and 6.9% of summer time is out of the comfort zone due to the high temperature. And the left 30.8% of summer time in beyond the comfort zone because of the damp. For mild season (spring and autumn), about 90.2% of time is comfortable, there are still 1.3% and 8.5% of time in beyond the comfort zone due to cold and damp respectively. However, there is only 8.9% of winter time in the comfort zone while most of the winter times is outside the comfort zone due to the low temperature and a few time due to the damp. It can be concluded that the traditional dwellings adapt well to the summer and mild season, but it has a poor indoor thermal comfort in winter.
80%
25
60%
fo
rt
zo n
e
20
40%
se as o
n
co m
15 10
M ild
Humidity ratio/(g/kg)
30
Summer comfort zone
5 0
20%
Winter comfort zone
-5
0
5
10 15 20 25 Temperature/℃
Mild season
Summer
30
35
40
Winter
Fig.5. Comfort zone of each season
3.4. Acoustic environment In order to investigate the performance of acoustic environment in Yuqing House, the measured sound pressures at different times are imported into MATLAB and then formed the SPL field cloud, as shown in Fig. 6(a-d). The SPL range of the dwelling is found to between 45dB(A) and 70dB(A). It is found that the SPL field cloud at 10:00 is similar to that at 14:00, which has a maximum SPL of 70dB(A) at the living room and outdoor due to human frequent activities, the average SPL of indoor is about 54 dB(A). At the time of 16:00 (c), a high sound pressure is found to extend at the outdoor which may caused by local people activity habits. By contrast, the SPL of both outdoor and indoor is decreased until at 18:00 (d) except the living room with the SPL reaching 65dB(A). It can be
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concluded that Huizhou vernacular dwellings has a well acoustic environment that can meet the acoustic standard of China. This is mainly benefited from the enclosed building forms and high external walls of these dwellings with no windows, which can greatly reduce the noise from the outdoor. On the other hand, the front and back patios also play a role of “sound lock” to keep away from the noise of outdoor.
a.10:00 b.14:00 c.16:00 d.18:00 Fig.6. SPL field cloud of indoor and outdoor
3.5. Visual environment
a.10:00 b.14:00 c.18:00 Fig.7. The illumination field cloud of indoor and outdoor
The patio has the function of day lighting and ventilation for buildings, thus it has a great impact on the indoor visual environment. In this study, the illumination was measured for a sunny day and then imported into MATLAB to form the illumination field cloud, as shown in Fig.7(a-d). At the time of 10:00(a), the maximum illumination of north wall can reach 200lux, and the illumination of bedrooms is lower than 50lux. It is found that the illumination of indoor is increased greatly at 14:00(b), e.g. the patio, living room, and the door near of bedroom can reach 600lux, 350lux, 200lux respectively. By contrast, the illumination of indoor is decreased largely at 18:00(c) except the front door with the illumination reaching 80lux. It can be concluded that the illumination variation of the living room is synchronized with that of the patio. It indicates that a high illumination can be obtained for the living room during daytime as it is directly connected to the patio. However, illumination variation of the bedroom is below 20lux which can’t comply with the suggested illumination of 300lux. This may be caused by the high external walls of Huizhou traditional vernacular dwellings without windows. 4. CONCLUSION (1) The characteristic of cold winter and cool summer in Huizhou traditional vernacular dwellings is demonstrated by one year measured data. The cool summer, which means indoor thermal comfort is good due to the compact building layout, high external wall and transition space such as patio which contributes to the sun shading
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and natural ventilation. Meanwhile, it shows that the dwelling has a good indoor environment and thermal comfort in spring and autumn. However, the indoor thermal environment is not really well for most of winter time, which is suggested to be improved by space heating. (2) The acoustic environment is complying with relevant standards for most of the rooms in Huizhou traditional vernacular dwelling, which mainly benefited from the enclosed building forms, high external walls with no windows of Huizhou traditional vernacular dwellings. (3) The daylight of living room and bedroom is mainly depending on the patio, which leads to insufficient visual environment some time and can’t satisfy the requirement of relevant standards. The main reason for that may be the high external walls without windows in Huizhou traditional vernacular dwellings. Acknowledgements This work is supported by the National Natural Science Foundation of China (No. 51478001) and the Student Research Training Program of China (No. 201710360045). The authors would like to sincerely thank the individuals who provided suggestions and comments during this study. References [1] M.J. Holmes, J.N. Hacker. Climate change thermal comfort and energy: meeting the design challenges of the 21st century, Energy and Buildings, 39(2007)802-814. [2] D.K. Kim. The natural environment control system of Korean traditional architecture: Comparison with Korean contemporary architecture, Building and Environment, 41(2006)1905-1912. [3] M. Baran, M. Yildirim, A. Yilmaz. Evaluation of ecological design strategies in traditional houses in Diyarbakir in Turkey, Journal of Cleaner Production, 19(2011)609-619. [4] M.K. Nematchoua, R. Tchinda , J.A. Orosa. Thermal comfort and energy consumption in modern versus traditional buildings in Cameroon: a questionnaire-based statistical study, Applied Energy, 114(2014)687–699. [5] R. Ooka. Field study on sustainable indoor climate design of a Japanese traditional folk house in cold climate area, Building and Environment, 37 (2002)319-329. [6] W.F. He, L. Yang, J.P. Liu. Climate adaptability development of Qinling mountains traditional dwellings, Architectural Journal, (2009)2426.(in Chinese) [7] X.R. Zhu , J.P. Liu, R.R. Hu. Energy performance of a new Yaodong dwelling, in the Loess Plateau of China. Energy and Buildings, 70(2014)159–166. [8] L. Jin, L.H. Zhao, Y.F. Zhang. Field study and modern enlightenment on thermal environment of traditional vernacular dwellings in Chaoshan area, Building Science, 30(6)(2014)27-31.(in Chinese) [9] X.Y. Chen, J.W. Xue, B Zheng. Field study on thermal environment of Quanzhou traditional Shoujinliao residence in summer, Architectural Journal, (2010)85-87.(in Chinese) [10] B.R. Lin, G.G. Tan, P Wang. Study on the thermal performance of the Chinese traditional vernacular dwellings in Summer, Energy and Buildings, 36(2004)73-79. [11] B. Song, L Yang, D.L. Liu. Field study on indoor thermal environment in Huizhou traditional residence in Xidi in winter, Architecture Technology, 45(11)(2014)1033-1036.(in Chinese) [12] E.Arens, L.Zeren, R.Gonzalez.et al. 1980 A new bioclimatic chart for environment design. Building Energy Management, Conventional and Solar Approaches, Proceeding of the international congress, Potugal. [13] M.L. Tan, B.Z. Li, W.J. Li, et al. Physiological Experiment for Human Thermal Comfort of Air Flow in Summer, Journal of Civil, Architectural＆Environmental Engineering, 33(2)(2011)70-73.(in Chinese)