Energy Consumption of Houses and Lifestyle in Cold Climatic Area of Japan

The 2005 World Sustainable Building Conference, 01-009 Tokyo, 27-29 September 2005 (SB05Tokyo)

ENERGY CONSUMPTION OF HOUSES AND LIFESTYLE IN COLD CLIMATIC AREA OF JAPAN

Kahori GENJO Dr.Eng.1 Shin-ichi MATSUMOTO Dr.Eng1 Ken-ichi HASEGAWA Dr.Eng1 Hiroshi YOSHINO Dr.Eng2

1 Department of Architecture & Environment System, Faculty of Systems Science and Technology, Akita Prefectural University, 84-4 Tsuchiya, Honjo, Akita, 015-0055, Japan, genjo/matsu/haseken@akita- pu.ac.jp 2 Department of Architecture & Building Science, Graduate School of Engineering, Tohoku University, 06 Aramaki, Aoba-ku, Sendai 980-8579, Japan, [email protected]

Keywords: energy consumption, house, lifestyle, cold climatic area, energy conservation

Summary In order to consider efficient residential energy conservation, measurements for energy consumption and indoor climate of four houses located in cold climatic area of Japan have been conducted for two years. Annual and monthly energy consumption classified by end-use, and energy consumption for some appliance in a typical summer and winter day were shown. In conclusion, 1) Total annual energy consumption per household was 40-78 GJ/year. 2)The annual energy consumption for space heating and hot water supply were to be about 70% of the total energy consumptions, showed a remarkable tendency with higher seasonal fluctuations, and varied house to house. 3) The annual energy consumptions in the end-use except for air-conditioning, presented smaller seasonal fluctuations and about 1 GJ per month in each house. 4) The difference of energy consumption among houses with same thermal performance was resulted from the differences of the space heating form and usage pattern of each appliance related with residents’ lifestyle. It is hoped that lifestyle solution would be selected and acted reasonably as one of available options. As an approach to this problem, it is expected to provide energy-saving information on each appliance for residents intelligibly and propose acceptable lifestyle options.

1. Introduction Growth in energy consumption of Japanese houses has been rising due to lifestyle changes, especially growth in ownership of appliances (Genjo et al., 2005). Kyoto Protocol entered into force on 16 February 2005, therefore it is necessary to reduce residential energy consumption for the solution of global warming and global sustainability. There is considered to be a limitation for the solution to residential energy conservation by improving insulation of houses and efficiency of appliances. Although some surveys show that the latest appliances use less electricity than conventional ones, lifestyle solution such as behavioral changes is believed to be more practical than investing energy saving ones, in view of the fact that most residents still use conventional ones. It becomes more important hereafter to promote lifestyle solution by behavioral changes such as the reduction of leaking electricity and control of set point in order to maximize the associated energy-saving potential. In order to clarify energy consumption for each appliance and consider possible lifestyles which result in residential energy conservation, measurements for energy consumption and indoor climate of four houses located in cold climatic area of Japan were undertaken for about two years since November, 2002.

2. Description of Investigated Houses and Measurement Method 2.1 Description of Investigated Houses Three detached houses and one apartment house were measured as typical residential examples in Akita Prefecture located in northern part of Japan called Tohoku area from the view point of their sizes, performances and energy sources. Table 1 summarizes the general characteristics of the houses. One house (house C) in Akita City and Three houses (house A, B and D) in Honjo City were measured. The latitude of Akita City is 39° 43’ N and the mean outdoor temperature for the month of January and August is - 0.4℃ and 24.4℃, respectively. Honjo City is located to the south of Akita City. Thermal performances of all investigated houses conform to the current Japanese residential standard for energy conservation. The total

- 55 - The 2005 World Sustainable Building Conference, Tokyo, 27-29 September 2005 (SB05Tokyo) floor areas of four houses vary from 78 to 161 m2. Family numbers range from three to four. In house D, resident changed in October 2003 due to former residents’ moving. The investigated houses included two all electrified houses (house A and B) using late-night electricity, and the energy sources used in other two houses (house C and D) were electricity, gas and kerosene. Table 2 shows description of facilities for investigated houses.

2.2 Measurement Method Investigation Items are shown in Table 3. Electricity, gas and kerosene consumption were measured. Temperature and humidity in the living room and bedroom at 1.1 m above floor surface, temperature at range hood and water temperature in toilet flushing tank were also measured. Devices and conditions for measurements are shown in Figure 1. The energy data failed to measure were compensated by referring to energy bills. In addition to the measurements, questionnaire survey and interview were conducted.

2.3 Investigated Appliances and Classification by End-Use Energy consumptions were examined and analyzed for two types of classification by end-use as shown in Table 4. The major classification is composed by the seven types of use: air-conditioning, hot water supply, cooking, entertainment/information, household/sanitation, lighting and others. The minor classification is equal to classification by each appliance.

Table 1 Description of Investigated Houses

Total Heat Loss Normalized House Building Completion Floor Structure Coefficient per Leakage Family Type 2 Unit Floor Area 2 2 Numbers Area(m ) 2 Area(cm /m ) (W/m ・K) Wooden A Detached 2000 109.3 frame 1.77 0.87 3 construction Wooden B Detached 2000 141.6 frame 1.79 0.77 4 construction Wooden C Detached 1999 160.6 frame 1.84 2.20 4 construction D Apartment 1993 78.3 Reinforced 1.68 1.52 4 concrete

Table 2 Description of Facilities for Investigated Houses

House Heating System Cooling System Hot Water System Cooking Ventilation System System Air-conditioner Air-conditioner Electric water Electric （ induction Mechanical A (cooling & heating, (cooling & heating, heater late-night exhaust electricity) electricity) electricity using） heating cooker Air-conditioner Electric water Electric Storage heater（late- （ induction Mechanical B night electricity using） (cooling & heating, heater late-night exhaust electricity) electricity using） heating cooker Hot water heating panel, Air-conditioner Gas Mechanical C (cooling & heating, Kerosene boiler kitchen supply and kerosene heater electricity) range exhaust Air-conditioner Gas D kerosene heater Gas water heater Natural (cooling & heating, kitchen ventilation electricity) range

Table 3 Investigation Items Measurement of Electricity Consumption Recorded every one minute Measurement of Gas Consumption Recorded every five minute Measurement of Kerosene Consumption Recorded every five minute Measurements of Temperature and Humidity Recorded every 15 minute Questionnaire Survey Lifestyle, annual income, usage of appliances Interview (Hearing) Outline of house, frequency of use and specification for each appliance, family constitution The 2005 World Sustainable Building Conference, Tokyo, 27-29 September 2005 (SB05Tokyo)

(a) Electricity consumption (b) Gas consumption

Figure 1 Devices and conditions for measurements.

Table 4 Measured Appliances and Two Types of Classification by End-Use

Major Classification Minor Classification (by Appliance) House A House B House C House D Air-conditioner (cooling & heating) ● ● ● ● Vented kerosene heater - - ● ● Air-Conditioning Electric heater - - ● - (Space Heating & Cooling) Humidifier ● ● ● ● Storage heater - ● - - Mechanical ventilation fan ○ ● ○ - Electric water heater ● ● - - Hot Water Supply Hot water supply system (gas), kerosene boiler - - ● ● Induction heating cooker ● ● - - Microwave, microwave oven ● ● ● ● Cooking Rice cooker ● ● ● ● Electric kettle, toaster ○ - ● ○ Refrigerator ● ● ● ● Dishwasher ● ● - - TV, VCR ● ● ● ● Audio components ○ ○ ● ○ Entertainment Game machine ○ ● ○ ○ /Information Personal computer ● ○ - ○ Telephone, fax ● ● ● ● Battery charger ○ ○ ● ○ Washing machine ● ● ● ● Iron ○ ○ ● ○ Household/Sanitation Vacuum cleaner ○ ● ● ○ Electric toilet seat ● ● ● ● Dryer ○ ○ ● ● Lighting Light fixture ● ○ ● ○ Portable light ○ ○ ● - Others Water tank - - ● - ●: measured individually ○: possessed but not measured -: not possessed

3. Results The results were mainly displayed as follows from the measurements for two years conducted from November 2003 to October 2004 except for comparison of annual energy consumption. The 2005 World Sustainable Building Conference, Tokyo, 27-29 September 2005 (SB05Tokyo)

3.1 Annual Energy Consumption by End-Use Figure 2 shows annual energy consumption by end-use for two years except house D, comparing with the statistic averaged in Tohoku area. “2003” and “2004” in Figure 2 means the data from December 2002 to November 2003, the data from November 2003 to October 2004, respectively. From an examination of Figure 2, total annual energy consumption per house was 40-78 GJ/year and less than the statistic averaged in Tohoku area (1997) with the exception of house C (2003). Japanese national averaged total annual energy consumption was about half of that of the United States (1998), probably due to the fact that the consumption of Japan (1997) for air-conditioning was about one fifth of that of the United States. Interestingly, the total annual energy consumptions of 2004 in house A, B and C were lower than that of 2003. It should be an expression of achievement of energy-conscious behaviors gradually during two-year measurement. In particular, the total annual energy consumption of 2004 in house C decreased significantly and was two thirds of that of 2003, because of the decrease of family number by commuter marriage and reduction of heating area by control of panel radiators. In view of end-use, the annual energy consumptions of measured four houses were 10-38 GJ/year for space heating, 0.002-0.4 GJ/year for space cooling, 12-19 GJ/year for hot water supply, respectively. Energy consumptions for air-conditioning of measured houses were lower than the statistic averaged in Tohoku area (1997) for the reason of higher insulation. The annual energy consumption for space heating and hot water supply were to be about 70% of the total annual energy consumption. Totally low consumption for space cooling resulted from cool summer, especially it appeared in 2003. The difference of annual energy consumption among houses was caused from the differences of the space heating form as shown in Table 2, usage pattern as well as performance of each appliance, and residents’ life style. Specifically, all rooms were heated constantly with storage heaters in house B and hot water heating panels in house C, in contrast with local heating intermittently with air-conditioners in house A, vented kerosene heaters in house D. The difference of annual energy consumption for hot water supply between house A and house B that use an electric water heater was about 4-5 GJ/year. This question is taken up in section 3.3. Accordingly, the reduction of the energy consumption for space heating and hot water supply would lead to efficient residential energy conservation, but the reduction of the energy consumption for other end-use would be considered to be similarly important.

3.2 Monthly Energy Consumption by End-Use As seen in Figure 3, energy consumptions for air-conditioning increased in winter and showed a remarkable tendency with higher seasonal fluctuations, and varied house to house. Similar tendency was seen in the energy consumptions for hot water supply. On the other hand, energy consumptions with the exception of the use for air-conditioning, presented smaller seasonal fluctuations and about 1-2 GJ per month in each house. It must be noted that piling of small reduction of energy consumption per household might make an effect in terms of national energy conservation.

Air-Conditioning Cooling Hot Water Supply Cooking Entertainment/Information Household/Sanitation Lighting House A (2003) 11.0 16.9 5.5 40.8GJ/year House A (2004) 9.6 16.2 6.5 40.0GJ/year House B (2003) 32.8 11.8 5.0 56.1GJ/year House B (2004) 30.4 11.9 5.3 52.4GJ/year House C (2003) 38.2 19.5 10.2 77.7GJ/year House C (2004) 16.1 16.2 9.7 49.5GJ/year House D (2004) 18.7 33.5 59.2GJ/year Tohoku area (1997) 29.7 16.7 62.8GJ/year Japan (1997) 12.9 16.3 46.4GJ/year 106.5GJ/year USA (1998) 53.9 20.1 32.5

0 20 40 60 80 100 120 Annual energy consumption [GJ/year]

House A (2003) 27.0 41.4 13.4 5.7 House A (2004) 24.1 40.6 16.3 6.3 House B (2003) 58.5 21.1 8.9 9.3 6.0 House B (2004) 58.1 22.7 10.2 House C (2003) 49.2 25.1 13.1 4.0 House C (2004) 32.5 32.8 19.7 7.2 2.6 House D (2004) 31.7 56.6 Tohoku area (1997) 47.3 26.5 25.9 Japan (1997) 27.8 35.1 35.1 USA (1998) 50.6 18.9 30.5 0 20 40 60 80 100 Shares [％]

Figure 2 Annual energy consumption by end-use. (Above: annual energy consumption by end-use. below: shares of annual energy consumption by end-use.) The 2005 World Sustainable Building Conference, Tokyo, 27-29 September 2005 (SB05Tokyo)

Lighting Household/Sanitation Entertainment/Information Cooking Hot Water Supply Air-Conditioning 10 70 60 8 From left to right house A, house B, house C, house D 50 6 40 Electricity in 4 House C 30 [GJ/year]

[GJ/month] N.A. 20 2 10 Annual energy consumption energy Annual Monthly energy consumption energy Monthly 0 0 Nov. Dec.Jan. Feb. Mar. Apr. May June July Aug. Sep. Oct. Annual 2003 2004 Figure 3 Monthly energy consumption by end-use.

3.3 Energy Consumption by Appliance For example of usage patterns of energy consumptions by appliances, daily profiles of energy consumptions by appliances for space heating, cooking and entertainment/information of house A and house B at 15 minutes’ intervals during 24 hours averaged for a week including a typical winter day (18 January 2004, average outdoor temperature of the day: -2.7℃) are shown in Figure 4(b)-(d) and (f)-(h). Temperature fluctuations are also shown in Figure 4(a) and (e). As seen in Figure 4(e), temperature is stable in house B, in contrast with house A shown in Figure 4(a). Energy consumption for space heating of house A with air-conditioners is less than house B with storage heaters, although temperature fluctuations of house A are larger than house B. (Notice that vertical axis is illustrated with different scale in Figure 4(b) and (f).) Therefore, quality of indoor climate would be higher in proportion to energy devoted, comparing to houses which have same level of thermal performance. In this case, residents of house B do not seem to realize they consume much energy because of using inexpensive late-night electricity for storage heaters. Connected with this, dishwasher operation at midnight in house A observed in Figure (c) can be explain as due to energy price. Needless to say, common appliances of both

30 50 ] ] ] 30 50 ] ℃ ℃ ℃

(a) Temperature 40 ℃ 2F living room (e) Temperature 40 30 1F living room 30 20 20 20 20 1F bedroom 10 2F bedroom 10 0 0 Outdoor Indoor temperature[ Indoor

Outdoor temperature[Outdoor Outdoor Outdoor temperature[ 10 -10 temperature[ Indoor 10 -10 2 10 Air-conditioner Air-conditioner in in stairs (b) Space Storage heater in 1F living room (f) Space 1F bedroom Heating Heating Storage heater in 2F 1 Air-conditioner 5 in 2F living room Storage heater in 1F Japanese room Energy consumption[MJ] Energy 0 consumption[MJ] Energy 0 0 1 2 3 6 8 9 10 11 12 13 1 1 16 1 18 19 20 21 22 23 2 1 (c) Cooking (g) Cooking Induction heating cooker Dishwasher 1 Microwave oven Induction heating cooker Refrigerator Refrigerator & rice cooker Microwave oven & rice cooker Energy consumption[MJ] Energy 0 consumption[MJ] Energy 0 0.4 0.4 (d) Entertainment (h) Entertainment /Information /Information TV & VCR in 1F living room 0.2 TV & VCR in 2F living room Personal 0.2 conputer Fax Game machine FAX Energy consumption[MJ] Energy 0.0 consumption[MJ] Energy 0.0 01234567891011121314151617181920212223 0 1 2 3 4 5 6 7 8 9 1011 1213 14 15 16 1718 1920 2122 23 Time [h] Time [h] Figure 4 Temperature fluctuations and daily profiles of energy consumptions by appliances for space heating, cooking and entertainment/information of house A and house B in a typical winter day (left: house A, right: house B). The 2005 World Sustainable Building Conference, Tokyo, 27-29 September 2005 (SB05Tokyo)

10 10 Electric water heater of house A in summer Electric water heater of house A in winter

5 5 Electric water heater of house B in winter Electric water heater of house B in summer Energy consumption[MJ] 0 Energy consumption[MJ] 0 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 01234567891011121314151617181920212223 Time [h] Time [h] Figure 5 Daily profiles of the energy consumptions by electric water heaters of house A and B in a typical summer and winter day (left: typical summer day, right: typical winter day). houses such as induction heating cooker and TV have different peak hours. Accordingly, it is needed to reconsider the usage pattern for each appliance associated with residents’ lifestyle in discussion of energy- saving potential. Similarly, Figure 5 shows daily profiles of the energy consumptions by electric water heaters of house A and B in a typical summer day (30 July 2004, average outdoor temperature of the day: 31.3℃) and a typical winter day. Both houses have a peak of energy consumption by electric water heater after 1:00 a.m. because of using late-night electricity. However, duration time of peak differs from house to house, as given in Figure 5. It would be caused by the differences of boiling temperature of electric water heater (85℃ in house A, 65℃ in house B) and total use of hot water in each house. Consequently, the energy consumption by electric water heater of house B is about half comparing to house A in winter. The effect of changing of the hot water usage on the energy consumption for hot water supply was identified.

4. Conclusions Measurements for energy consumption and indoor climate of four houses located in cold climatic area of Japan have been conducted for about two years and the following conclusions were obtained: 1) Total annual energy consumption per household was 40-78GJ/year. 2) The annual energy consumptions for space heating and hot water supply were to be about 70% of the total energy consumptions in any investigated house, showed a remarkable tendency with higher seasonal fluctuations, and varied house to house. 3) The annual energy consumptions in the end-use except for air-conditioning, presented smaller seasonal fluctuations and about 1 GJ per month in each house. 4) The difference of energy consumption among houses with same thermal performance was resulted from the differences of space heating form and usage pattern of each appliance related with residents’ lifestyle. Looking ahead, residential energy consumption is likely to be affected by the trend of lifestyle increasingly. It is hoped that lifestyle solution would be selected and acted reasonably as one of available options. As an approach to this problem, it is expected to provide energy-saving information on each appliance for residents intelligibly and propose acceptable lifestyle options.

References Genjo, K. 2005, Relationship between possession of electric appliances and electricity for lighting and others in Japanese households, Energy and Buildings, 37, pp.259-272. Jyukankyo Research Institute 1999, Energy Handbook for Residential Sector, The Energy Conservation Center, Tokyo (in Japanese). Energy Efficiency, Technology, and R & D, International Energy Agency 2001, IEA Data Base. Institute for Building Environment and Energy Conservation 1999, Energy Conservation Standard for Next Generation Residence (in Japanese).

Acknowledgements This study was financially supported by the Ministry of Land, Infrastructure and Transport, the Tokyo Electric Power Company, the KANSAI Electric Power Co., Inc., the CHUBU Electric Power Co., Inc. and the KYUSYU Electric Power Co., Inc. The present work was carried out as a part of research project “National Scale Research on Energy Consumption in the Residential Buildings” by Committee on Academic Activities of the Architectural Institute of Japan.