Most of existing government office building in Iran were designed and built without enough consideration to the daylight design. Therefore a lot of electricity energy should be used to provide visual comfort in office rooms in government office buildings. Due to location of Kerman City of Iran, There are a lot of solar radiation in whole year during working hours in exterior spaces. In this research daylight quality of 4 office rooms in 2 government office buildings in Kerman city of Iran were investigated through experimental measurement and calculating some daylight parameters such as mean Work PlaneIlluminance (WPI), Work Plane Illuminance Ratio (WPI Ratio) and daylight Ratioin two conditions when lights were on and off. Finding of this research reveals that most of office building in government building cannot reach the acceptable range of different parameters of daylight even though lights were on. Therefore research about daylight quality in office rooms in this region is an important issue to be investigated to find different methods and solutions for improving daylight quality in office rooms. Keywords: Daylight Quality, Government Office buildings, Working Plane Illuminance, Working Plane Illuminance Ratio, Daylight Facto

Gharaati, Mehran

Kermani, Ali Yazhari

Mahdavinejad, Mohammadjavad

English

International Institute for Science, Technology and Education (IISTE): E-Journals

Journal of Energy Technologies and Policy                                                                                                                                      www.iiste.org ISSN 2224-3232 (Paper)   ISSN 2225-0573 (Online) Vol.4, No.9, 2014  29 Daylight Parameters and Operation Quality Case Studies: Public Office Buildings in Kerman, Iran  Mohammadjavad Mahdavinejad Faculty of Art and Architecture, Tarbiat Modares University, Tehran, Iran Email: mahdavinejad@modares.ac.ir  Mehran Gharaati Faculty of Architecture, Esfahan University of Art, Esfahan, Iran E-mail: mehrangharaati@gmail.com  Ali Yazhari Kermani(Corresponding author) Faculty of Architecture, Esfahan University of Art, Esfahan, Iran E-mail: ali_yazhari56@yahoo.com  Abstract Most of existing government office building in Iran were designed and built without enough consideration to the daylight design. Therefore a lot of electricity energy should be used to provide visual comfort in office rooms in government office buildings. Due to location of Kerman City of Iran, There are a lot of solar radiation in whole year during working hours in exterior spaces. In this research daylight quality of 4 office rooms in 2 government office buildings in Kerman city of Iran were investigated through experimental measurement and calculating some daylight parameters such as mean Work PlaneIlluminance (WPI), Work Plane Illuminance Ratio (WPI Ratio) and daylight Ratioin two conditions when lights were on and off. Finding of this research reveals that most of office building in government building cannot reach the acceptable range of different parameters of daylight even though lights were on. Therefore research about daylight quality in office rooms in this region is an important issue to be investigated to find different methods and solutions for improving daylight quality in office rooms. Keywords: Daylight Quality, Government Office buildings, Working Plane Illuminance, Working Plane Illuminance Ratio, Daylight Factor  1. Introduction In order to provide convenience condition from different aspects such as Thermal comfort, lighting and ventilation, a lot of energy should be used (Yeang, 1996).Around 20 to 30% of energy is consumed in building for providing visual comfort (Lam and Hui, 1996, Lam, 2000). Daylight utilization is one of possible methods for minimizing electricity for artificial lighting(Lam, 1995, Li and Lam, 2001). Daylight utilization not only causes a lot of energy for building but also it is considered as a source of heat generation in buildings. Therefore proper use of day lighting, minimize energy use for cooling system. Furthermore most of people prefer daylight due to the more beauty ofdaylight (Baker and Steemers, 2000). Daylight is considered as an important parameters for reduce energy consumption in buildings(Galasiu et al., 2004, Li and Lam, 2000, Huang et al, 1989, Li, et al.,2008).Daylight utilization is an important strategy for energy saving as well as visual comfort. There are several parameters to evaluate daylight quality in office rooms.Working Plane Illuminance, Working Plane Illuminance Ratio and Daylight Factor are some of daylight parameters to evaluate daylight quality.Dubois (2001) had studied some of lighting quality standards from different sources. Some of recommended values for different parameters are tabulated in table 1.In order to have daylight utilization and visual comfort, a lot of parameters of Daylight should be considered.  1.1 Work Plane Illuminance  Work plane Illuminance as an indicator of daylight, is used to check the quality of daylight in spaces. Different places need different amount of WPI due to different activities in different places(IES, 1993). WPI should be 500 Lux to have enough potential for reading and writing. Acceptable range for Work Plane Illuminance is 300 – 500 lux for offices (CIBSE,1994). If Work Plane Illuminance is less than 100 lux, the office room is considered too dark for paper and computer work. If the amount of work plane illuminance is between 100-300 lux, the office room has acceptable range of daylight for computer work but this is not acceptable for paper work. If work plane illuminance is between 300- 500 lux, thisamount of Work Plane Illuminance is acceptable for paper work and ideal for computer work. The light of office roomis suitable for paper work and too bright for computer whenWork Plane Illuminance is higher than 500 lux (Dubois, 2001). Journal of Energy Technologies and Policy                                                                                                                                      www.iiste.org ISSN 2224-3232 (Paper)   ISSN 2225-0573 (Online) Vol.4, No.9, 2014  30 1.2 Work Plane Illuminance Ratio  Work plane Illuminance can be calculated by dividing minimum WPI which is recorded in a specific point by average WPI or maximum WPI at any given time. The indicator shows the uniformity of light inside the room. Acceptable range of WPI ratio means suitable distribution of light inside office room. WPI ratio is considered acceptable when (minimum / average) of WPI is less than 0.8 CIE (1986) and CIBSE (1994). According to Dubois (2001) the acceptable range of WPI ratio (minimum/maximum) is 0.5(Dubois, 2001).  1.3 Daylight Factor  Daylight factor can be determined by dividing the mean WPI by global illuminance in a same time(Robbins, 1985).The Daylight Factor is an indicator for evaluating the potential of space for daylight utilization. Daylight factor between 2 and 5 % means the space has enough potential for use of daylight Dubois (2001).  Table 1: Performance indicators and their interpretation (Dubois, 2001) # Performance indicator Interpretation 1 DAYLIGHT FACTOR < 1 % 1-2 % 2-5 % > 5 % unacceptable acceptable preferable ideal for paper work / too bright for computer work 2 WORK PLANE Illuminance < 100 lx 100-300 lx 300-500 lx > 500 lx  too dark for paper and computer work too dark for paper work / acceptable for computer work acceptable for paper work / ideal for computer work ideal for paper work / too bright for computer work 3 WORK PLANE Illuminance Ratio Emin/Emax > 0.5 Emin/Emax > 0.7  acceptable ideal ideal  2. Research Methodology In order to evaluate daylight quality in government office buildings, 4 office rooms in 2 government office buildings (Judicial complex of Kerman and Department of Telecommunication of Iran) in Kerman city, were selected for experimental measurement in terms of WPI, WPI ratio and daylight Factor. Kerman is located on a high margin of Kavir-e Lut (Lut Desert) in the central south of Iran.FurthermoreKerman is located at latitude 30.29 and longitude 57.06. At first physical characteristics of each room such as Length, Width, Height, Window area and orientation were recorded. In order to record Working plane Illuminance (WPI), with respect to the room index, 4 or 9 points were specified to install Luxmeter on the work plane height.Room index can be calculated by the following equation. Room Index = (lengths × width)/[Mountingheight ×(length + width)]  Table 2: Room Index and No. Measuring Positions Room index minimum number of measuring positions Less than 1 4 1 to below 2 9 2to below 3 16 3 or greater 25  At the same time as recording internal Working plane Illuminance, the external Illuminance was recorded by another Luxmeter which has been installed outside building without any obstruction. Work plane illuminance for each room and external Illuminance were recorded in different time of working hours (9 a.m., 12 p.m. and 3 p.m. to find out the Quality of daylight in different times of working hours.  Journal of Energy Technologies and Policy                                                                                                                                      www.iiste.org ISSN 2224-3232 (Paper)   ISSN 2225-0573 (Online) Vol.4, No.9, 2014  31 3. Finding and Discussion Physical Characteristics of 2 government office buildings, judicial complex of Kerman and Department of Telecommunication of Kerman are shown in figure 1 and figure 2 respectively.              Figure 1: A view of judicial complex of Kerman        Figure 2: Department of Telecommunication   Two rooms, office room No.215 and No.222 were selected in judicial complex of Kerman for experimental measurement and another two rooms, office room No.2 and No.8 inDepartment of Telecommunication of kerman were selected for daylight measurement. Physical characteristics of these office rooms are tabulated in table 3. Figure 3 and 4 are views of Office room No. 222 and No. 2respectively.  Table 3: Physical and Geometric characteristics of measured rooms No. Floor Level Window Height (mm) Cill Height (mm) Window Orientation Ceiling Height (mm) Geometry (W x L x H) (mm) WWR 215 1 1670 900 West(N45°) 3800 4400 x 7440 x 3800 0.17 222 1 2200 900 East (S45°) 3800 4200 x 7550 x 3800 0.29 2 3 1600 900 East (N23°) 3600 6400 x 7700 x 3600 0.23 8 3 1600 900 West(N23°) 3600 6400 x 10000 x 3600 0.22              Figure 3: A view of office room No. 222              Figure 4: A view of office room No. 2          Mean external Illuminance during measurement in different hours for each selected room are shown in table 4. Table 4: Mean external Illuminance in different hours for different office rooms Office rooms External Illuminance (LUX) 9 a.m. 12 p.m. 3 p.m. No. 215 , No.222 80418.6 83310.2 40590 No.2 , No.8 79744 78642 35030  Mean work plane illuminance and external Illuminance for different office rooms in different times during working hours are tabulated in table 5.  Journal of Energy Technologies and Policy                                                                                                                                      www.iiste.org ISSN 2224-3232 (Paper)   ISSN 2225-0573 (Online) Vol.4, No.9, 2014  32 Table 5: Mean work plane illuminance for different office room Office rooms WPI (LUX) 9 a.m 12 p.m 3 p.m Lights on Lights off Lights on Lights off Lights on Lights off No. 215   590.8333 130.8333 701.1667 169.5 665.8333 141.8333 No.222 1166.667 662.1667 772 275 633.3333 160.1667 No.2  1845 1745.222 764.8889 673.6667 376.1111 299.6667 No.8 469 236.3333 527.2222 306 485 258.3333  Figure 5 reveals the amount of WPI in different office rooms in different hours when lights were on.  Figure 5: WPI in different Office rooms in different hours when lights were on  Figure 5 reveals that when lights were on during working hours, Most of office rooms have had WPI higher than 500 lux in different hours which is considered too bright for computer work. Only Room No.2 at 3 p.m. and Room No.8 at 9 a.m. and 3 p.m. have WPI between 300 and 500 lux which is considered acceptable for paper work and ideal for computer work. Therefore none of office rooms could not achieve acceptable light in all hours during working hours while lights were on.  Figure 6 reveals the amount of WPI in different office rooms in different hours when lights were on.                  Figure 6: WPI in different Office rooms in different hours when lights were off  As it is shown in Figure 6, among all measured rooms, only room No.8 at 12 p.m. reach the recommended value in term of work plane illuminance when lights were off. The amount of work plane illuminance in room no.8 at 9 a.m. and 3 p.m. are 236 and 258 lux respectively when lights were off which is too dark for paper work howeverthis amount of work plane illuminance is acceptable for computer work. When lights were off, the amount of work plane illuminance is less than 300 lux in office room No.215 in all hours Journal of Energy Technologies and Policy                                                                                                                                      www.iiste.org ISSN 2224-3232 (Paper)   ISSN 2225-0573 (Online) Vol.4, No.9, 2014  33 during working hours.Room No.222 and No.2 could not reach the acceptable light during working hours at all, when lights were off. Therefore it can be concluded that none of office room has ability to achieve acceptable daylight during working hours when lights were off. Table 6 shows the amount of WPI Ratio (Min/ Max) in different office rooms in differenttimes during working hours when lights were on and off  Table 6: work plane illuminance Ratio for different office rooms in different hours Office rooms WPI Ratio (Min/Max) 9 a.m 12 p.m 3 p.m Lights on Lights off Lights on Lights off Light on Lights off No. 215 0.46 0.49 0.43 0.38 0.38 0.31 No.222 0.40 0.46 0.32 0.25 0.38 0.2 No.2 0.3 0.32 0.3 0.3 0.33 0.31 No.8 0.38 0.34 0.3 0.21 0.25 0.17  As it can be seen in table 6, none of office rooms in different times could reach the acceptable range of WPI ratio (Min/Max) with 0.5 for both conditionswhen lights were on and off. Therefore it can be concluded the office rooms in government office buildings don’t haveuniformity of light during working hours even though lights were on.  Table 7 shows daylight Ratio in different office rooms in different hours when lights were on and off. Table 7: Daylight Ratio for different office rooms in different hours Office rooms Daylight Ratio 9 a.m. 12 p.m. 3 p.m. Lights on Lights off Lights on Lights off Light on Lights off No. 215 0.73 0.16 0.84 0.2 1.6 0.3 No.222 1.4 0.82 0.92 0.33 1.56 0.39 No.2 2.3 2 0.97 0.85 1.07 0.85 No.8 1.45 0.82 0.92 0.33 1.5 0.39  According to table 7, most of office rooms have more daylight ratio when lights were on respect to the condition when lights were off in different hours during working hours. Table 8 shows surface reflectance of surfaces such as wall, ceiling and floor in different office rooms.  Table 8: Surface Reflectance of different surfaces for different office rooms  Office rooms Surface Reflectance Wall Ceiling Floor No. 215 70 50 40 No.222 70 40 40 No.2 80 50 60 No.8 80 50 60  According to IES(1993), the recommended values for surface reflectance of wall, ceiling and floor are 50%, 70% and 20% respectively. Surface reflectance of wall and floor in all office rooms is more than recommended values which is specified in IES (1993). Surface reflectance of ceiling in all office room is lower than 70%.  4.Conclusion It can be concluded that however some of office rooms can achieve acceptable daylight quality in a specific time during working hours but all office rooms could not reach the acceptable daylight quality in term of work plane illuminance during working hours in term of different parameters such as work plane illuminance and uniformity of light (WPI Ratio) in both conditions when lights were on or off. Surface reflectance of different surfaces has significant effect on daylight quality. However surface reflectance of walls in all office rooms in government office building is more than recommended values but surface reflectance of ceiling in all office rooms are less than recommended values which is suggested by IES (1993). Therefore all government office buildings were not designed for using daylight. Therefore, proper daylighting design is required for visual comfort in government office buildings.  Journal of Energy Technologies and Policy                                                                                                                                      www.iiste.org ISSN 2224-3232 (Paper)   ISSN 2225-0573 (Online) Vol.4, No.9, 2014  34 References Baker, N. & Steemers, K. (2000). Energy and Environment in Architecture. London: Taylor & Francis. CIBSE (1994). Code for Interior Lighting. London, UK: Chartered Institution of Building Services Engineers (CIBSE). Dubois, M.C., Impact of Solar Shading Devices on Daylight Quality: Measurements in Experimental Office Rooms, Research Report, 2001, Lund, Sweden, Lund University. Galasiu, A. D., Atif, M. R. & Macdonald, R. A. (2004). Impact of Window Blinds on Daylight-Linked Dimming and Automatic On/Off Lighting Controls. Solar. Energy-Journal of the International Solar Energy Society. 76 (5), 523-544. Huang, Y. J., Thom, B., & Ramadan, B. (1989). A daylighting design tool for Singapore based on DOE-2.1 C simulations. In Proceedings of the ASEAN special session of the ASHRAE Far East conference on air-conditioning in hot climates. 26-28 October. Kuala Lumpur. IES (1993). Lighting Handbook: Reference and Application. (8thEd.) Illuminating Engineering Society of North America (IESNA). Lam, J. C. & Hui, S. (1996). Sensitivity Analysis of Energy Performance of Office Buildings. Building and Environment. 31 (1), 27-39. Lam, J. C. (1995). Building Envelope Loads and Commercial Sector Electricity Use in Hong Kong. Energy, 20 (3), 189-194. Lam, J. C. (2000). Energy Analysis of Commercial Buildings in Subtropical Climates. Building and Environment. 35(1), 19-26. Li, D. H. W. & Lam, J. C. (2000). Measurements of Solar Radiation and Illuminance on Vertical Surfaces and Daylighting Implications. Renewable Energy. 20 (4), 389-404. Li, D. H. W. & Lam, J. C. (2001). Evaluation of Lighting Performance in Office Buildings with Daylighting Controls. Energy and Buildings. 33 (8), 793-803. Li, D. H. W. & Tsang, E. K. W. (2008). An Analysis of Daylighting Performance For Office Buildings In Hong Kong. Building and Environment. 43(9), 1446-1458. Yeang, K. (1996). Bioclimatic Skyscraper, London, Uk: Artemis London. The IISTE is a pioneer in the Open-Access hosting service and academic event management.  The aim of the firm is Accelerating Global Knowledge Sharing.  More information about the firm can be found on the homepage:  http://www.iiste.org  CALL FOR JOURNAL PAPERS There are more than 30 peer-reviewed academic journals hosted under the hosting platform.   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Daylight Parameters and Operation Quality Case Studies: Public Office Buildings in Kerman, Iran

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Daylight Parameters and Operation Quality Case Studies: Public Office Buildings in Kerman, Iran

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