A Case Study about Comfort Level in Residential Space.

Transcription

1 Proceedings of 7 th Windsor Conference: The changing context of comfort in an unpredictable world Cumberland Lodge, Windsor, UK, April London: Network for Comfort and Energy Use in Buildings, A Case Study about Comfort Level in Residential Space. Hatsuki Takahashi* and Keiko Takahashi** *Japan Minka Revival Association **Department of Living Arts and Sciences, Aichi Konan College Abstract Japanese traditional houses set on the basis of a comfortable life in summer in order to avoid the heat and humid climate. Those were designed with less wall space and large windows thus making it well-ventilated. However, Japanese modern houses have become westernized with smaller windows since Japan began importing foreign home construction materials and methods of construction. Therefore the modern houses have come to rely on air-conditioning to cool the home. Thus, it may be said that the modern Japanese houses may not be suitable for Japanese climate and environment. In this study, we considered the problems from different standpoints based on the research on comfort level and investigation of temperature-humidity in residential space and suggested our opinion about the matter. Keywords: House climate, Traditional house, Thermal Comfort, Humidity Comfort Comfort Level Instruction In this paper, we introduce our case studies and suggest our opinion. The case studies are Studies on Microclimate of Folk house in Japan, Study of the elderly in their house in Aichi and Surveys in U.K. and Japan. The Studies on Microclimate of Folk house in Japan was conducted by Prof, Hanaoka. Keiko Takahashi (formerly Ichikawa) was one of a member of this. The Study of the elderly in their house in Aichi was the part of A study on the relationships between heating methods and the health conditions of the elderly in their house. Authors did Aichi part. The surveys in U.K. and Japan was done for thesis by Hatsuki Takahashi. 1. Studies on Microclimate of Folk house in Japan This is the surveys which author did from 1965 to In that time, Japanese traditional houses were already disappearing. The aim of these studies was to put on records of traditional Japanese houses and to leave the ancestral wisdom of houses. It had not been examined the traditional houses were adjusted to the environment and the climate in the region. Therefore, we chose the region which is the harsh natural environment and did surveys on house climate at folk house Folk house of Doza style in Yamagata This is the result of studies on the thermal features of Doza style house in Hasedo of Yamagata City of Yamagata Prefecture. It was examined the thermal conditions in this style of folk house from November, 1967 to July, Natural environment of the object region Yamagata Prefecture is located Tohoku district on the Sea of Japan side; Yamagata city is located between the Sea of Japan and the Pacific though. It is also the city surrounded by mountains, the Mt. Asahi (1871m) on the west and the Mt. Zao 1

2 (1841m) on the east. Hasedo is located the west-south of Yamagata City. There are mountains around up to 800m on the south of Hasedo. The mountains lead to the mountain which is 1227m. The snowfall period is from the end of November to the end of March. The air temperature in Yamagata city is harsh in summer and winter. Compare to Sakata city which located similar latitude by the sea, Yamagata city has more tropical days and more winter days. A tropical day is a day on which the outdoor temperature is 30 degrees or above. A winter day is a day during which the temperature falls below zero degrees. These are barometers of variations in climate. The house of surveyed The estimated age of the house was about 200 years. This house had not been reconstructed for years so almost remained original form (see Figure1-1,1-2). The roof was thatched but the part of Zenbu was Galvanised iron sheet roof. The openings were sliding paper screens (Shoji: translucent white paper pasted on to a lattice frame) and panes. The ceiling of Nakanoma was slatted (Sunoko) ceiling 260cm above of flooring. Half of Zashiki by the Nakanoma was also slatted ceiling. Flooring was board floor except Zashiki. It had Doza style flooring (see Figure1-3,1-4). Figure1-1. The floor plan (The numbers are the point of measurement) 1. The surface of the floor (Nakanoma) 2. The surface of the ground (Zashiki) cm above the floor (Zashiki, north) 4. The inside of rice husks (Zashiki) 5. The outdoor (north) cm above the floor (Zashiki, south) 7. On the top of a beam (Zashiki) 8. The outdoor (south) 9. The surface of the floor (Iroriba) cm above the floor (Iroriba) cm above the floor (Nakanoma) 12. The surface of the rush mat (Zashiki) 2

3 Figure1-2. The house photo of appearance from south east Figure1-3. The structure of Doza Figure1-4. The photo of Doza room The result of this survey We classified months into three seasons, from December to February for winter, from March to May for spring, from June to July for summer. Figure1-5 shows the ascending ratios of room temperature in each season and each room. Figure1-6 shows the maximum and minimum temperature in each season and each room at sunny days. It is the mean temperature of each season. The numbers correspond with the floor plan. We used ascending ratios of room temperature as one of barometer of house climate. The method of calculation is as given below. A=(t max t min ) / (T max T min ) A: ascending ratio of room temperature t max : maximum temperature of room t min : minimum temperature of room T max : maximum temperature of outdoor T min : minimum temperature of outdoor 3

4 Figure1-5. The ascending ratios of room temperature Figure1-6. The maximum and minimum temperature In Doza room, room temperature scarcely varied and the ascending ratio of room temperature was almost fixed in three seasons. On the other hand at Nakanoma and Iroriba with the board floor, temperature was very changeable in each season and easily influenced by outdoor temperature. Variations of temperature were slight both through the day and the year on the surface of the ground of Doza. The ascending 4

5 ratio of room temperature of Doza room was very low and nearly invariable. In winter, maximum and minimum temperatures in Doza room were higher than the others (board floor). Temperature in Nakanoma and Iroriba (board floor) rose rapidly from spring to summer. There was little difference among the temperatures of three rooms in summer. From the results, temperature in Doza room was also higher than the others (board floor) through the day in winter. Temperature on the surface of the ground was almost fixed through day and year. As a result of the observation it was found that the Doza room was warmer than the room with the board floor (Nakanoma and Iroriba) in winter. The difference of temperature among Nakanoma, Iroriba and Doza room was getting slight, as it becomes summer. It was considered, therefore, that even in midsummer Doza room was more bearable Folk House of Steep Gable (Gassyo) Style in Shirakawa This is the result of studies on the thermal features of steep gable (Gassyo) style house in Shirakawa Village of Gifu Prefecture. The house of this style is three or four storied and has thatched roof which has steep slant of 60 degrees. It was examined the thermal conditions in this style of folk house from July, 1968 to April, Natural environment of the object region Gifu Prefecture is located middle of Japan. Shirakawa Village is located north west of Gifu Prefecture. It is the city surrounded by mountains, the Hida mountain range on the east, the Hakusan Mountains on the west. There were studded 23 hamlets at an alluvial fan by a ravine. This region was an area of high snowfall. The record of a maximum snow accumulation was 356cm 23 rd of January, 1934 so far. The snowfall starts from the beginning of November and continuous snow cover sees the end of April. The house of surveyed The object house was preserved the feature of Gassyo relatively accurate from the others (see Figure2-1,2-2). The house was located at 740m altitudes. There were mountains, 850m altitudes on the east and the Mt. (1719) on the west. The north and south was relatively flat. The structure was four stories, thatched roof (about 20cm thick), the outer wall was boarded, and the openings were sliding paper screens and panes. The floorings were straw-mats (Tatami) and board floor at ground floor and upper stories had board floor and slatted flooring. The slatted flooring on the first floor was small only as a chimney. Figure2-3, 2-4 show the structure of Gassyo. It was the house made for the silkworm-raising. There were the place for people on ground floor and the place for silkworms on upper stories (attic). Figure2-1. The photo 5

6 Figure2-2. The floor plan 1Choda 2Okunode 3Dei 4Oe 5Usunawa 6Daidokoro (ground floor) 789(first floor) 12outdoor 10(second floor) 11(third floor) Figure2-3. The Gassyo structure Figure2-4. Tie timbers without nail The result of this survey We classified months into four seasons, from July to August for summer, from September to November for autumn, from December to February for winter, from March to April for spring. Figure2-5 shows the ascending ratios of room temperature in each season and each room. The numbers correspond with the floor plan. The ascending ratios of room temperature of Oe, Dei, Chouda and Okunodei on ground floor were very low and nearly invariable and were scarcely affected by outdoor temperature. Compare that, the ascending ratios of room temperature of Usunawa and Daidokoro on ground floor and upper stories were very large in the winter and spring, especially remarkable in winter. In summer and autumn, the ascending ratios of room temperature in upper stories were larger than the ground floor (without Usunawa and Daidokoro). Usunawa was kitchen with stove and Daidokoro was dinning-living room with sunken fireplace in the middle of the room. This was affected the ascending ratios of room temperature of these rooms. The upper stories, there was a possibility of influence by solar radiation over the roof. To consider that, we examined the variation curve of room temperature in summer that 6

7 outdoor temperature was high and in spring that outdoor temperature was low. Both of them, we chose an example of sunny day and rainy day. The example of summer sunny day, room temperature of grand floor showed lowest and becoming upper story, the temperature became higher. The temperature of top story showed highest. When a kitchen stove was used at Usunawa from half past five, there was no sign of influence of that heat to the upper stories. At the night time, the difference between each story was same as day time. The example of summer rainy day, the difference of temperature between each room and outdoor was slight although there was same difference between the stories in sunny day. As the result of these, there were scarcely affected by solar radiation over the roof in summer. The example of spring sunny day, the indoor temperature was higher than outdoor. The difference of temperature between the stories showed same as summer although the difference of temperature was bigger than those of in summer. While using fireplace at Daidokoro, there was no sign of influence of that heat to the upper stories. The example of spring rainy day, the temperature rising was slight at outdoor and each room. There was used fireplace all day at Daidokoro, there was no sign of influence of that heat to the upper stories. The temperature of stories were nearly same. As the result of these, there were affected by solar radiation over the roof in spring. For the reasons stated above, the upper stories ware more influenced by solar radiation over the roof and the influence was bigger in winter than in summer. We calculate the amount of solar radiation influenced with this roof (13/10, about 52 degrees) and modern house with gentle slope roof (4/10) from the result (see Figure2-6). Figure2-5. The ascending ratios of room temperature 7

8 Figure2-6. The amount of solar radiation Comparison between Steep Gable (Gassyo) and Modern House We investigated the effects of roof slope and of thatching or shingling materials upon the indoor climates of folk houses which are represented by sleep gable (Gassyo) house and modern house with gentle slope roof. We examined the thermal conditions in modern house with gentle slope roof house from May, 1970 to April, We examined the amount of solar radiation on 18 th of May and 20 th of August, At the same time, we also examined the sleep gable (Gassyo) house that was the object house above. The modern house of surveyed The object house was located at 700m altitudes. There were mountains around 750m on the south and east. The house was partly two stories, Galvanised iron sheet roof, boarded outer wall and panes openings. The floorings were straw-mats (Tatami) and board floor. The photo and floor plan show Figure2-7,2-8. Figure2-7. The photo month 8

9 Figure2-8. The floor plan 1 ground floor 2 first floor 4 ground floor with heater 5 outdoor The result of this survey The difference of indoor temperature of gentle slope roof house from the outdoor temperature was always larger than that of steep gable house in summer, while in winter the difference between these two styles was not distinct. The ascending ratios of indoor temperature of gentle slope roof house were remarkably larger when compared with those of steep gable house in summer, while it is quite conversely in winter. This fact seems to be due to the differences of roof pitch and of covering materials, that is, gentle slope roof receives more solar radiation comparing with steep gable in summer and the radiation heat penetrates more into the Galvanised iron sheet roof than the thatch. The examination of the amount of solar radiation corresponded to the calculation showed Figure2-6. From the results, it became obvious that the mean temperature of air of a day in gentle slope roof house was larger than that in steep gable house and also the upper the story was, the mean became larger. The daily ranges of indoor temperature became larger when the story was upper and the difference of the mean temperature between the two roof styles is scarcely observed. In summer, the humidity was also affected the comfortableness. We calculated the absolute humidity from the relative-humidity and the air temperature observed. It was always higher the gentle slope roof than the steep gable in summer. This means that the steep gable house is more bearable in summer. 9

10 1-3. Folk House of Okabe Style in Heavy Snowfall District This is the result of studies on the comparison between the indoor climates of Okabe style folk houses and modern houses of new style with mortar walls in Shiramine Village, Ishikawa Prefecture. Natural environment of the object region Ishikawa Prefecture is located middle part of Japan by the Japanese sea. Shiramine Village is located at the foot of the range of Hakusan (2702). The range is on the south-east, so that the prevailing wind from north-west hit by the range. It courses heavy snowfall in this district. The snowfall period is from the beginning of November to April but continuous snow cover can see in May. The amount of snowfall is about 2m a year although it becomes 5m at the heavy snowfall year. And also the village is located inland, it is hot in summer. As the result, the annual temperature range is big. The houses of surveyed We examined four houses, A, B, C and D. Figure3-1 shows the photo of A (Okabe) which has a door on the first floor above a door roof of the ground floor. Figure3-2 is the floor plan of A on the ground floor. Figure3-3 is the photo of B (Okabe) and Figure3-4 is the house plan. Figure3-5 is the photo of C and Figure3-6 is the house plan. This house was the one of the biggest houses of Okabe style. It was covered with Okabe completely and no resident was there, so that it was good example to examine. Figure3-7 is the photo of D and Figure3-8 is the house plan. The house D is modern house of new style with mortar walls. Okabe means thick wall about 30cm. The structure is three-layered made by mud (see Figure3-9). It was for silkworms and storage on upper stories at the Okabe houses. Figure3-1. The photo of A (Okabe) Figure3-2. The floor plan of A (Okabe) Figure3-3. The photo of B (Okabe) 10

11 Figure3-4. The floor plan of B (Okabe) Figure3-5. The photo of C (Okabe) Figure3-6. The floor plan of C 11

12 (Okabe) 12

13 Figure3-7. The photo of D (Mortar) Figure3-9. The structure of Okabe Figure3-8. The floor plan of D (Mortar) The result of this survey In summer the difference between the diurnal mean temperature of the room and that of the outdoors is bigger in mortar walls than in Okabe house. As for mortar walls, the ratio of daily range of temperature is large and the phase delay of the times, when temperature attains to maximum is small. Therefore they are more affected by the outdoor temperature. This is the same in winter. The over-all coefficient of heat transmission of mortar walls is bigger than that of Okabe. Mortar walls are inferior to Okabe in the heat resistance. The ascending ratio of the room temperature of house with mortar walls is about 1.1 hr -1. From the results of described above, it was found that house with mortar walls are easily affected by the outdoor temperature and are inferior in the indoor climate environment compared with Okabe house. We also did a survey by questionnaire. The result of the questionnaire; they feel that Okabe house is cooler in summer and warmer in winter than the house with mortar walls. When they rebuild their houses, however, most of them intend to build the house of new style Native House of Ranging Huts System in Amami Island This deals with the result of investigation of indoor-climates of the native house of ranging huts system in Amami Island of Kagoshima Prefecture, where is subtropical in climate, during the last week in July of We have some comparison between the indoor-climates of it and of concrete house built in the same place. Natural environment of the object region There is the one of the heaviest rain district and extremely humid climate. The object region is Kakeroma Island (see Figure4-1). 13

14 Figure.4-1 The map Amami Island Kakeroma Island Amami Island The houses of surveyed Figure.4-2 The photo of the native house Figure.4-2 is the photo of the native house of ranging huts system and Figure.4-3 is the floor plan of that. The roofs are thatched (mentioned in the plan) and Galvanised iron sheet. The pitch of the roof is 13/10 on thatched roof and 5/10 on Galvanised iron sheet roof. Figure.4-4 is the photo of the concrete house and Figure.4-5 is the floor plan. The roof is Galvanised iron sheet and the pitch of the roof is 5/10. Figure.4-3 The floor plan of the native house Figure.4-4 The photo of the concrete house 14

15 Figure.4-5 The floor plan The result of this survey The indoor temperature of the native house is almost the same to the outdoor temperature, while that of concrete house is always higher (about 2 degrees) than that of outdoor air. The solar radiation influences less on the indoor-climate of the native house as compared with concrete house by the heat-insulating effect and by the steep slant of the thatched roof. The absolute humidity of the native house is also the same to the outdoor air, while in the concrete house it is rather higher than that of outdoor air. The temperature-humidity index shows higher value in the concrete house when compared with that of the native house. The reason of the above mentioned results seems to be the enough ventilation through wide apertures and by simple room arrangement in the native house. It can be said the native house of ranging huts system, which is created by long experiences, is most suitable residence in subtropical region such as Amami Island. 15

16 2. Study of the elderly in their house in Aichi This is the part of A study on the relationships between heating methods and the health conditions of the elderly in their house. This study was to clarify how humidity affects the health conditions of the elderly in heated rooms in winter; a questionnaire was conducted in six districts in Japan. Representatives from three of the six districts were selected to investigate the actual conditions of temperature and humidity in their living environments. Humidity was experimentally adjusted to various levels and the effects of the changes on skin dryness assessed, with the results suggesting local differences in the methods and times of heating, heating adjustments according to subjective thermal sensation and relationships between environmental temperature/humidity and health condition. Authors investigated the actual conditions in Aichi part. We found out the results as follows. The objects of the investigation We investigated 6 houses from February to March, The object person was one of the residents in the house. The table below is the age, period of investigation at room (for 1 week) and the around a body (for 2 days), the kind of heating at daytime room and heating time. The house of No.4 person was in same room at daytime and night, the data of daytime room investigated at living room though. The others had a bedroom but hardly used heating there. The No.3 and No.4 houses were modern style of house and the others were traditional style of house. The No.1 house was attached a shop so that the daytime room was the shop. The No.3 person was out during daytime so the hours of using of heating are low. Table.1 The 6 houses No. age period of investigation heating at daytime room room around a body kind of heating hours 1 74 From 10 to 15 of Mar. 14 & 15 of Mar. oil fan heater From 9 to 15 of Mar. 10 & 11 of March electric carpet oil heater 13 gas fan heater 3 66 From 2 to 8 of Mar. 6 & 7 of March electric carpet 0.5 oil heater From 1 to 7 of Mar. 3 & 4 of March oil heater From 23 to 29 of Feb. 26 & 27 of March oil heater From 22 to 28 of Feb. 23 & 24 of March electric carpet 12 oil heater 12 The result of this investigation At the bedroom of No.1, No.2, No.5 & No.6, the humidity is stable high. No.2 has a little change, it seems to be due to reconstruction the house had. No.3 is modern house and the bedroom is influenced by the outdoor humidity. This region is dry in winter, so the influence of humidity is big problem. No.4 bedroom is stable on temperature and humidity because this house uses heating. Modern style house is getting like this house which is well-insulated airtight housing. These houses need electrical appliances to control house climate. In this investigation, there were not used air-conditioning as heating but some people who live in modern style of house use air-conditioning in summer and winter. The people who live in traditional style of house rarely have air-conditioning. 16

17 3. Surveys in U.K. and Japan This is the surveys which author did from In Japan, people claim that Japanese houses are small and uncomfortable. The aim of this survey is to investigate the fact. For that reason, we did the survey in England as well for comparison. We asked the comfortableness and the size in each room in their house. Questionnaire was conducted in England and Japan. We received about 50 answers in both. The Table.2 is the percentage of the age and gender distribution of respondent sample. Table 3 is the percentage of the kind of houses which they live. At some of the houses, we did investigation of the house plan and how they use the house. Table.2 The age and gender distribution of respondent sample Japan U.K. age male female male female 10~ 2% 4% 0% 0% 20~ 2% 47% 2% 35% 30~ 5% 4% 6% 16% 40~ 4% 7% 2% 2% 50~ 5% 9% 8% 16% 60~ 4% 2% 6% 6% 70~ 2% 4% 0% 2% sum 24% 76% 24% 76% Table.3 The kind of houses U.K detached 26% semi-detached 40% terraced 19% bungalow 5% cottage 2% flat 5% maisonette 2% others 2% Japan detached 53% bungalow 3% flat 43% The result of this surveys We found out the result from the Questionnaire. The size of Living room, people who said big is about 60 percent in U.K. In Japan, it was less than 10 percent. The comfortableness of Living room, more than 80 percent of the U.K. people were satisfied. In Japan, it was about 40 percent. The size of Dining room, less than 15 percent people said small in U.K. In Japan, it was about 50 percent. The comfortableness of Dining room, more than 75 percent of U.K. people were satisfied but it was less than 25 percent in Japan. The size of bedroom, more than 60 percent of U.K. people said big however it was about 15 percent in Japan. The comfortableness of bedroom, about 70 percent of U.K. people were satisfied although it was about 40 percent in Japan and about 25 percent of Japanese were dissatisfied. Japanese people mostly feel room is small and uncomfortable. However, there is not so much difference the size of room between U.K. and Japan from the result of the investigation of the house plan. 17

18 Conclusion The above is the outline of our surveys. To understand these results correctly, the housing situation of Japan is described as follows. The form of a traditional house in Japan was completed in Edo period. The house did not influence by the foreign country because Japan had closed the country. However, there were various restrictions by the class in Edo period, too. After the country was opened to the world, it came to receive the influence of the foreign country rapidly. Moreover, because the restriction had disappeared, it came to build the house freely. In the house of the upper class, the best place located in the southeast of the house was a drawing room. For these reasons, there were a lot of houses unsuitable for life and environment. A lot of houses disappeared by the Great Kanto Earthquake in The standard of a narrow house of about 25m 2 was put out in the 1940's. After World War II, an extreme housing shortage continues, and it became the age of the amount from the quality. The house came to become high-priced goods when it became a high economic growth period of the 1950's. The major company came to sell uniform houses throughout Japan. It is necessary to maintain regularly the traditional houses with mud wall and thatched roof. Before the high economic growth period, residents had cooperated to maintain. However, it became too hard to do that because they worked hard and didn t have enough free time. It made people think modern houses is better. In addition, when it came to be able to control the environment in the house by electricity, the tendency was accelerated. Thus, the house of today has been made without any relation to the comfort and people are not yet recognised their house properly. They consider the earthquakeproof, however, the people who said the earthquake-proof is important, they hardly anchor furniture. Now, the economy has reached deadlock in Japan. It is the time that we reconsider our houses from various angles. References Hanaoka, T (1991), The ecology of traditional folk house. Kaiseisha Press, Japan Hanaoka,T, Yanase, T, Ichikawa, K, Oguri, C & Igarashi, Y (1971), Studies on Microclimate of Folk House in Japan Part Ⅷ Comparison between Indoor-climates of Steep Gable (Gassyo) Style House with Thatch Roof and of Gentle Slope Roof House with Iron Plate in Shirakawa District. Research Journal of Living Science, Vol.18, No.2, pp Ichikawa, K, Kaneko, K, Yanase, T & Hanaoka,T (1970), Studies on Microclimate of Folk House in Japan Part Ⅴ On the Thermal Conditions in Fork House of Doza Style in Yamagata. Research Journal of Living Science, Vol.17, No.1, pp Ichikawa, K, Ozawa, M, Kurosaki, Y, Yanase, T & Hanaoka,T (1970), Studies on Microclimate of Folk House in Japan Part Ⅵ On the Comparison between the Indoor climates of Mortar Wall House and Okabe Style House in Heavy Snowfall District. Research Journal of Living Science, Vol.17, No.2, pp

19 Igarashi, Y, Takahashi, K, Yanase, T, Obuchi, R, Hashimoto, S & Kitahara, H (2000), A Study on the Relationships between Heating Methods and the Health Conditions of the Elderly in their Houses. Japan Society for the Promotion of Science, No27, 2000 Morita, S, Ichikawa, K, Yanase, T & Hanaoka,T (1972), Studies on Microclimate of Folk House in Japan Part Ⅸ On the Indoor-climate of Native House of Ranging Huts System in Amami Island, Kagoshima Prefecture and Comparison between the Houseclimates of it and of Concrete House. Research Journal of Living Science, Vol.19, No.1, pp Yanase, T, Imamura, F, Ichikawa, K & Hanaoka,T (1969), Studies on Microclimate of Folk House in Japan Part Ⅳ On the Thermal Conditions in Fork House of Steep Gable (Gassyo) Style in Shirakawa. Research Journal of Living Science, Vol.16, No.1 2, pp