Implementation of CIE General Sky Model Approach in Ukraine and Effects on Room Illuminance Mode

Transcription

1 , pp Implementation of CIE General Sky Model Approach in Ukraine and Effects on Room Illuminance Mode Oleg Sergeychuk 1* and Dmitriy Radomtsev 2 Department of architectural constructions Kiev national university of construction and architecture, Kiev, Ukraine 1 ovsergeich@mail.ru, 2 graphichart65@gmail.com Abstract New standard CIE S 011/E:2003 CIE standard general sky was accepted in Ukraine in With its adoption the question of its appropriate usage with national documents became an important event. Feasible way of standard s utilization with Ukrainian daylighting standards and effects of its implementation are given in the paper. Keywords: Building climatology; CIE general sky; systems of room daylighting 1. Introduction In 2003 an international standard CIE S 011/E:2003 [1] was accepted, which provide 15 main types of standard skies for daylight calculation. Document is basing on the comprehensive study of R.Kittler, S.Darula and R.Perez [2]. This primary standard was identical translated and applied in Ukraine in 2010 [3]. Mentioned documents describing only mathematical modeling of daylight spatial distribution but not providing method of usage in architectural practice for estimation and designing systems of room daylighting. Ukrainian designers have some questions: which sky type is required under designing systems of room daylighting in specific geographical locality? how to take into consideration fact that standard sky types are varying in the course of year? From the moment of new standard enactment a numerous foreign investigations of standard sky types gradations for different specific localities have been taken. PR Tregenza proposed the method for defining of sky types occurrence [4]. It is basing on the best fit comparison of the observed sky spatial luminance data retrieving by the 145 patches camera and summary horizontal illuminance with the results of luminance modeling under CIE Standard General sky. Basing on the provided method W.Li, L.Tang, M.Lee and T.Muneer take study in which they perform measurements of sky luminance in Hong Kong from 1999 to On the minimal RMSE approach using neural networks they defined 3 standardized sky types with the greatest repetition frequency in the course of year [5]. Afterwards other group of researchers made more accurate derivation and proposed a set of 4 general skies for Hong Kong [6]. In addition to existing efforts in [2] R.Kittler and S.Darula proposed an approach for definition adjustment of sky types by vertical illuminance [7]. Following M. Fabian made exploration of types occurrence in Bratislava [8]. Also well-known investigations of general sky gradation in Chile [9] and Singapore [10]. Listed papers is not enough responding to the formulated questions. * Corresponding Author ISSN: IJSH Copyright c 2016 SERSC

2 In 2010 in Ukraine standard DSTU-N B V :2010 «Building climatology» was accepted [11], in which presented behaviors of cloudiness, irradiance and climatology indicators for Ukraine regional centers. Quantities of zenith luminance can be derive from the Satellight program data [12]. The main aim of paper is the development of offer for utilization mentioned above standards for designing of room daylighting systems for Ukrainian localities basing on the existing climatology data [11, 12]. Effects of CIE general sky usage on reference room s illuminance mode are given in the paper. 2. CIE General Sky Application in Ukraine 2.1. Geometric Apparatus of General Sky Model In [3] all sky types deriving by 3 groups of cloudiness: overcast, intermediate and clear. Each of sky conditions is describing mathematical by single formula of spatial luminance distribution. Geometric apparatus consist of following components (Figure 1): sky dome which is representing by hemisphere with relative radius in spherical coordinate system; sun point on the hemisphere surface which position is defining by azimuth and elevation in specified time and day; arbitrary sky element calculation with specified azimuth and elevation for which relative and absolute luminance point is determining. The main parameters of system are two functions that combine relative position of elements: φ(z) luminance gradation function that incorporate vertical position of sky element and zenith describing vertical distribution form horizon to zenith; f(χ) relative scattering indicatrix that combine horizontal position of element and sun describing horizontal pattern of luminance distribution. Figure 1. Geometric Apparatus of General Sky Model Each of sky types is deriving by six light-climatic parameters and individual set of coefficients by meaning of two mentioned functions [3, Table 1] that is placing into formula of relative luminance distribution calculation: 58 Copyright c 2016 SERSC

3 , (1) where L γ luminance of arbitrary sky element, cd/m 2 ; L z zenith luminance, cd/m 2 ; γ angle of elevation of arbitrary sky element, rad; Z angular distance between a sky element and the zenith, rad; χ shortest angular distance between sky element and sun, rad; Z s angular distance between the sun and zenith, rad; a,b,c,d,e coefficients that deriving group of gradation and scattering indicatrix of sky type [3, table 1] Defining of General Sky Types for the Territory of Ukraine On the assumption of [2] basic parameters that describing sky types are: sky dome group by cloudiness; D v /E v ratio of diffuse illuminance to extraterrestrial horizontal illuminance; T v luminous turbidity factor; L z /D v ratio of absolute zenith luminance to horizontal diffuse illuminance. 1. By cloudiness behavior sky dome can be derive by the repetition frequency of days with certain cloudiness value basing on the available Satellight data [12] with subsequent attitude to specific group. Table 1. Kiev CIE General Sky Types Month І ІІ ІІІ IV V VI VII VIII IX X XI XII Cloudy Intermediate Cloudless Group II II II III III III III III II II II II II 2. For the reason that solar data in DSTU-N «Building climatology» [Table 8, 11] are radiant quantity for the comparison it has to be convert into luminous quantities. Generally luminous flux of lighting source with continuous spectrum is: e ( ) V ( ) d, (2) 380 where Ф luminous flux, Lm; Φ eλ (λ) spectral density of radiation flux; V(λ) spectral luminous efficiency function [13]. Thereby spectral density of diffuse and direct radiation flux for horizontal surface has been got basing on the climatic data [11] for of June, 15 and December, 15 for Kiev and other 24 regional centers. Calculations are provided with usage of bundled software SMARTS [14-16]. Atmosphere profile, volume fractions of atmosphere elements, model of atmospheric aerosol and optical thickness received from international documents and satellite data [17-19]. Basing on the diagrams of solar radiation s spectral distribution tables of the spectral density for the June, 15 and December, 15 has been got. Values of the relative spectral density for other days ca be obtain with the interpolation. Thereby Copyright c 2016 SERSC 59

4 using formula (2) with coefficients of the relative spectral density and knowing quantities of spectral luminous efficiency function (ISO 11664:2007(E) [13]) for the CIE 1931 standard observer, the values of the direct and diffuse illuminance were obtain. Figure 2. Solar Radiation s Spectral Distribution, Kiev, Ukraine Figure 3. Solar Radiation s Relative Spectral Distribution in Visible Range For the determining of D v /E v ratio diffuse irradiation data D e_mon from DSTU-N «Building climatology» need to be lead to instant value D e and then to instant luminous quantity D v basing on formula (2). D e mon D e n t _ (3) where D e instant horizontal diffuse radiation in real cloudiness conditions, W/m 2 ; D e _ mon summary monthly horizontal diffuse radiation in real 60 Copyright c 2016 SERSC

5 cloudiness conditions, MJ/m 2 [table 8, 11]; n day s amount in specific month; t duration of daylight hours, sec. As mentioned above E v horizontal illuminance reaching outer limit of Earth s atmosphere and can be define by: E v E v 0 sin, (4) γ s where E v0 luminous solar constant, , lx [20]; γ s solar altitude, rad. Table 2. Defining of D v / E v Data D e_mon, MJ/m D e, W/m E v, D v, D v/e v T v luminous turbidity factor that in this mathematical model can be determine by following formulas: Tv ln( Pv / E v ), (5) a v m where P v instant direct horizontal illuminance, lx; a v luminous extinction coefficient; m optical air mass. 1 a v , (6) m sin γ s m (7) (γ s ) Instant direct horizontal illuminance can be calculated similarly to diffuse value. Table 3. Defining of T v Data D e_mon, MJ/m P e, W/m P v, m a v T v Copyright c 2016 SERSC 61

6 4. For the derivation of L z /D v ratio zenith luminance satellite data [12] can be taken. In this work is used information of the 1996 year as the closest data to the basic CIE S 011/E 2003 measurements. Absent information in east regional centers was defined with the Satellight approach in use of ARSC-CIE sky model [21], according which zenith luminance is: / z v i i s i s i L D [ a c c o s Z c e x p ( 3 Z ) d ], (8) where a i, c i, c / i, d i coefficients that describe light-climatic parameters by e sky s clearness, [table 4, 21] which can be determine by: e [( D v E v _ n ) / D v 3 3 kz s ] /[1 kz s ], (9) E v_n instant normal direct radiation in real sky condition, Lx; Δ sky s brightness given by:, (10) D v m / E v 0 m relative optical air mass. Table 4. Defining of T v Data L z, kcd/ m L z /D v Basing on information about cloudiness group, D v /E v, T v, L z /D v ratios monthly CIE general sky types for Kiev have been defined (Table 5). Table 5. Defining of CIE General Sky Types for Kiev, Ukraine Month І ІІ ІІІ IV V VI VII VIII IX X XI XII Sky type ІV.2 9 ІV.3 10 ІV.4 11 ІV.4 11 ІV.3 10 ІІІ.2 6 For the comparison of the defining results we can use the horizontal diffuse illumination data from the Ukrainian climatology standard [11], absolute zenith luminance quantities and calculated values of horizontal illuminance that have been obtained during modeling of the sky luminance surface according to the formula 1. Surface modeling is processing with the bundle software Diffused solar radiation. Illuminance can be calculated as the integral behavior of light field by formula: E L (, ) c o s d, (11) 62 Copyright c 2016 SERSC

7 where L (, ) - luminance of arbitrary sky element in specified direction by angles and, cd/m 2 ; cosβ function of radiation value; ω solid angle in which radiating surface is defining, ster; Table 6. Comparison of Meteorological and CIE General Sky Calculated Horizontal Diffused Illuminance Data for Kiev, Ukraine Data D v, Sky type ІV.2 9 ІV.3 10 ІV.4 11 L z, kcd/m E d_calc, E,% ІV.4 11 ІV.3 10 ІІІ.2 6 On basis of proposed method was analyzed the remaining part of Ukraine (Table 7) and proposed a map of light-climatic zoning by D v (Figure 4). Figure 4. Map of Light-climatic Zoning of the Territory of Ukraine by D v Copyright c 2016 SERSC 63

8 Table 7. Source Data, Intermediate Calculations and Defining of CIE General Sky Types for the Territory Of Ukraine Regional center D e, W/m 2 D v_year_mid, Lx L z_year_mid cd/m 2 L z/d v D v_calc, Lx E,% 1 Vinnytsia 114, , ,16 2 Dnipropetrovsk 116, , ,11 3 Donetsk 113, , ,56 4 Zhytomir 115, , ,72 5 Zaporizhia 114, , ,12 6 Ivano-Frankivsk 112, , ,10 7 Kiev 117, , ,41 8 Kirovohrad 118, , ,64 9 Luhansk 114, , ,20 10 Lutsk 114, , ,26 11 Lviv 112, , ,68 12 Mykolaiv 119, , ,04 13 Odesa 120, , ,64 14 Poltava 115, , ,70 15 Rivne 114, , ,14 16 Simferopol 121, , ,82 17 Sumy 113, , ,20 18 Ternopil 111, , ,80 19 Uzhhorod 115, , ,50 20 Kharkiv 114, , ,17 21 Kherson 120, , ,92 22 Khmelnytskyi 111, , ,60 23 Cherkasy 117, , ,17 24 Chernivtsi 113, , ,68 25 Chernihiv 117, , ,23 sky type 2.3. Defining of Calculation Sky Types for the Territory of Ukraine As seen from the Table 5 annual sky condition of Ukraine response to the single sky type -. But over a year period light-climatic behaviors have a wide general skies range [22] that is why more appropriate approach is a data calculation of luminance distribution by per month defining of sky type with subsequent derivation of annual year data of relative luminance distribution. Evaluation of luminance distribution have been held for 15-th of every month. For the defining of daily annual distribution for each whole hour modeling luminance data by the appointed CIE general sky type (Figure 5, a) and on basis of received information annual daily/monthly values are defining (Figure 5, b). Modeling occur in software environment «MatLAB» with utilization of bundled software «Atmospheric radiation» [23]. Figure 5. Luminance Distribution Surfaces for Kiev. a Hourly Distribution, March,15; b Monthly Distribution, March 64 Copyright c 2016 SERSC

9 Definitive annual year data of spatial luminance distribution deriving as value from all-month annual monthly information (Figure 6). As the result we obtain array of annual year data and table of relative quantities of luminance distribution arbitrary sky elements in spherical coordinate system with 10 step. Figure 6. Surface of Year Spatial Luminance Distribution for Kiev Table 8. Year Coefficients of Luminance Distribution for Kiev Elevation/ Azimuth Application in national building standard can be obtain by the replacement of calculation formula of q і, coefficient that considering irregular luminance of arbitrary sky element, with the obtained table of annual year relative luminance distribution for every regional centre of Ukraine. At the meantime coefficient is calculating for the standard overcast CIE sky: 3 q (1 2 sin θ ), i (12) 7 where θ angular height of centre of the arbitrary sky element relatively to the calculation point. Intermediate quantities can be obtain using interpolation. Subsequent calculations execute according to the existing method of daylight computation. More detailed information is given in [24] Influence of CIE General Sky Model on Room Luminance Conditions Analysis of house illuminance mode is basing on comparison and analytic review of illuminance data of working plane in conditions of CIE standard overcast sky and determined CIE general sky types. Study provide for Kiev (50 34 N, E) over whole year for AM and 15 th date of each month. For analysis typical living room Copyright c 2016 SERSC 65

10 with dimensions 3.0x6.0m is select. Window size is 1.7x2.1m with double glazing and transmitting efficiency 78%. Calculation points are choosing according to the national sanitation standard with step 1 meter and height 0.8m above floor. Study results of month data for CIE standard overcast sky (Figure 7, Table 9) and determined CIE general sky types (Figure 8, Table 10) are shown below. Figure 7. Illuminance Mode of Reference Room from January to December in Conditions of CIE Standard Overcast Sky Table 9. Illuminance Mode of Reference Room December in Conditions of CIE Standard Overcast Sky for Kiev, Ukraine Data Sky type CIE standard overcast sky E d_calc, E d_ext, DF,% Copyright c 2016 SERSC

11 Figure 8. Illuminance Mode of Reference Room from January to December in Conditions of Determined CIE General Sky Types Table 10. Illuminance Mode of Reference Room December in Conditions of Determined CIE General Sky Types for Kiev, Ukraine Data Sky type E d_calc, E d_ext, ІV.2 9 ІV.3 10 ІV.4 11 ІV.4 11 ІV.3 10 ІІІ DF,% As seen from the mentioned above tables usage of CIE general sky model have a great influence on room illuminance mode with identical window s dimensions in both cases annual horizontal illuminance on working plane and daylight factor is 31% and respectively 35% higher than with CIE standard overcast sky model. Detailed analysis of both cases is presented in Table 11. Table 11. Comparison of Average Illuminance Mode Data Data E d_calc, E d_ext, CIE standard overcast sky CIE standard general sky E, % DF,% Copyright c 2016 SERSC 67

12 3. Conclusions and Future Prospect Research Adoption of new calculation model brings an opportunity for more accurate evaluation of daylighting over a period of a whole year. In case of annual year lighting behaviors rising relative to CIE overcast sky, calculation level of daylighting will increase what will bring for more rationally utilization of artificial lighting and increment of whole energy efficiency level. For the future research derivation of annual year luminance distribution tables and detailed investigation of new sky model impact onto the lighting behaviors of buildings is planning. Acknowledgment The authors thank to DSc R.Kittler for the valuable remarks during the research and organizing committee of ACE2015 conference for the possibility of publication. References [1] J. Clerk Maxwell, A Treatise on Electricity and Magnetism, vol. 2, (1892), pp [2] R. Kittler, R. Perez and S. Darula, A set of standard skies, (1998). [3] Kiev: State Enterprise, "Ukrainian Scientific-Research Center of Standardization", National standard of Ukraine, (2013), p. 7. [4] P. R. Tregenza, Analysing sky luminance scans to obtain frequency distributions of CIE Standard General Skies, Light. res. and tech., vol. 36, (2004), pp [5] W. Li, L. Tang, M. Lee and T. Muneer, Classification of CIE standard skies using probabilistic neural networks, International journal of climatology, vol. 30, (2009), pp [6] E. Ng, V. Cheng, A. Gadi, J. Mu, M. Lee and A. Gadi, Defining standard skies for Hong Kong, Building and Environment, vol. 42, (2007), pp [7] S. Darula, R. Kittler and L. Komar, Sky type determination using vertical illuminance, Przegląd elektrotechniczny, vol. 6, (2013), pp [8] M. Fabian and S. Darula, Occurrences of standard skies and luminous turbidity factor in Bratislava, Advanced Materials Research, vol. 855, (2014), pp [9] M.. B. Piderit, C. Cauwerts and M. Diaz, Definition of the CIE standard skies and application of the HDRI technique to characterize the spatial distribution of daylight in Chile, Journal of Construction, vol.13, (2014), pp [10] S. Wittkopf and L. Soon., Analysing sky luminance scans and predicting frequent sky patterns in Singapore, Light. res. and tech, vol. 39, (2007), pp [11] Кiev, Building climatology, National standard of Ukraine, (2011), p [12] Satellight, The European database of daylight and solar radiation, [13] CIE Colorimetry - Part 1: Standard Colorimetric Observers, CIE Central Bureau Vienna, (2007). [14] Standard Tables for Reference Solar Spectral Irradiances: Direct Normal and Hemispherical on 37 Tilted Surface, [15] Simple Model of the Atmospheric Radiative Transfer of Sunshine (SMARTS), rredc/smarts/. [16] Standard solar constant and zero air mass solar spectral irradiance tables, Standards/E490.htm. [17] AFGL Atmospheric constituent profiles (0-120km), Optical physics division, Air force geophysics laboratory, [18] Guide to reference and standard atmosphere models, _2010_9-10.pdf, (2010). [19] Aerosol optical thickness, NASA database, MODAL2_M_AER_OD&date= [20] Guide to Recommended Practice of Daylight Measurement, CIE Tech. Rep., Commission Internationale de l Eclairage, Vienna: CIE Central Bureau Vienna, (1994). [21] R. Perez, P. Ineichen, R. Seals, J. Michalsky and R. Stewart, Modeling daylight availability and irradiance components from direct and global irradiance, Solar energy, vol. 44, (1990), pp [22] D. Radomtsev, Defining of sky types for Kiev basing on DSTU ISO 15469:2008, Energy efficiency in construction and architecture, vol. 7, (2015), pp [23] V. Bazhenov, P. Lizunov, O. Pidgorny, V. Plosky and O. Sergeychyk, Applied Software «Atmospheric Radiation» for an Energy Efficient Building, 14th International Conference on Computing in Civil and Building Engineering, (2012); Moscow. 68 Copyright c 2016 SERSC

13 [24] O. Sergeychuk and D. Radomtsev, Employment features of CIE S 011/E:2003 (ISO 15469:2004) CIE standard general sky under designing systems of room daylighting, 9 th International Conference of Future generation communication and networking, (2015); Jeju Island, South Korea. Authors Sergeychuk Oleg, he is a Doctor of technical sciences, professor of the Department of architectural constructions. Radomtsev Dmitriy, he is a Post-graduate student at Department of architectural constructions. Copyright c 2016 SERSC 69

14 70 Copyright c 2016 SERSC