1、UDC 628.92.021 : 628.972 :628.98:001.4: 521.9 Daylight in interiors Principles DEUTSCHE NORM February 1985 DIN 5034 Part 2 Tageslicht in Innenrumen; Grundlagen Together with DIN 5034 Part 1, February 1983 edition, supersedes DIN 5034, December 1969 edition, which was withdrawn in 1982. In keeping wi
2、th current practice in standards published by the International Organization for Standardization (ISO), a comma has been used throughout as the decimal marker. I DIN 5034 “Daylight in interiors“ consists of the following Parts: Part 1 General requirements Part 2 Principles Part 4 (at present at the
3、stage of draft) Part 5 (at present at the stage of draft) Measurement Simplified method of determining minimum window sizes for living areas Contents Page Page 1 Scope and field of application . 1 2.12 Clear sky. 2 2 Terms and definitions 1 2-13 Overcast sky 2 2.1 Altitude of the sun ys . 1 2-14 Ave
4、rage sky. 2 2-2 Solar azimuth 3 Astronomical principles . 2 2.3 Declination of the sun 6 . 1 4 Photometric principles. . 5 1 . . 2.5 Duration of sunshine. 1 4-1 Overcast sky 2.4 Equation of timeZgl. . 2.6 Potential duration of sunshine. . 2 4-2 Iear sky* . 2.7 Relative duration of sunshine 2 4.3 Ave
5、rage sky. . lo 2.8 Sunshine probability. . 2 5 Physical radiation principies 11 2.9 Solar constant it is a function of the time of day, the time of year and the geographical latitude of the place concerned. 2.3 Declination of the sun 6 The angle between the centre of the sun and the celestial equato
6、r; it is a function of the time of year. (1) + 23 26,Y 2 2 - 23 26,5 2.4 Equation of time Zgl The difference between true local time (WOZ) and mean local time (MOZ), because of the fluctuations in the length of the solar day according to the time of year. 2.1 Altitude of the sun ys + 16rnin252Zgl2-1
7、4rnin 17s (2) The angle between the centre of the sun and the horizon, from the observers viewpoint; it is a function of the time of day, the time of year and the geographical latitude of the place concerned. 2.5 Duration of sunshine The sum of the intervals of time within a given period of time (ho
8、ur, day, month, year) during which the irradiance Continued on pages 2 to 13 euth Verlag GmbH, Berlin 30. has exclusive sale rights for German Standards (DIN-Normen) DIN 5034 Part 2 Engl. Price group 10 03.86 Sales No. O1 10 Page 2 DIN 5034 Part 2 of the direct solar radiation on a plane perpendicul
9、ar to the direction of the sun is equal to or greater than 120 W/m2 (about 11 O00 Lx). Note. This irradiance level is recommended as the threshold value for bright sunshine by the World Meteorological Organization (WMO) 1 1. Earlier sets of data are based on a threshold value of about 200 W/m2. 2.6
10、Potential duration of sunshine The sum of the time intervals within a given period during which the sun is above the actual horizon, which may be limited by mountains, buildings, trees, etc. 2.7 Relative duration of sunshine Ratio of the duration of sunshine to the possible dura- tion of sunshine wi
11、thin the same period of time. 2.8 Sunshine probability The long-term mean of the instantaneous values of the relative duration of sunshine. 2.9 Solar constant Eo The irradiance from the extraterrestrial solar radiation on a plane perpendicular to the direction of incidence at the mean distance of th
12、e sun. ( 3) E, = 1,37 kW/m2 2.10 Total radiation Sum of direct and diffuse solar radiation. Unless other- wise specified, the overall radiation is referred to the horizontal plane. Note. Diffuse solar radiation was formerly referred to as (diffuse) sky radiation. 2.11 Turbidity factor T The ratio of
13、 the vertical optical thickness of a turbid atmosphere to the vertical optical thickness of a clean, dry atmosphere (Rayleigh atmosphere) referred to the complete solar spectrum. 2.12 Clear sky Cloudless sky for which the relative luminance distribu- tion is specified in CIE Publication No. 22 (TC-4
14、.2) 2. 20 min 10 O - 10 -7n 2.13 Overcast sky Completely overcast sky for which the ratio of the luminance at an altitude y above the horizon to the luminance L, at the zenith is specified as L, (1 + 2 sin y) 3 L, = (4) 2.14 Average sky The mean over several years of all sky states, the day- light i
15、llumination and physical radiation data of which are described by means of the local probability of sun- shine. 3 Astronomical principles The daylight conditions are essentially determined by the position of the sun, which for the given place, is described by the altitude of the sun yc and the solar
16、 azimuth es as a function of the time of day and the time of year. The following equations refer to the centre of the suns disc. Normally the calculation is based on true local time (WOZ). For statements in Central European Time MEZ), it is necessary to convert as follows: MEZ = MOZ + 4. (15“-A) . m
17、ini0 and MOZ = WO2 - Zgl where MO2 is the mean local time; A is the geographical longitude of the place of observation east of Greenwich; Zgl is the equation of time, in min. Summer time, where applied, shall also be taken into account in stating times (Central European Summer Time MESZ = MEZ + 1 h)
18、. The equation of time Zgl and the declination of the sun 6 change during the year. They can be obtained from astronomical almanachs 3, or calculated from equa- tions (7) and (8) 4, or read off from figures l and 2. In equations (7) and (81.J is the day of the year (e.g. for Ist January, J = 1 and f
19、or 31st December, J = 365 or 366). - Jan. Feb. Mar. Apr. May Jun. Jul. Aug. Sep. Oct. Nov. Dec. Figure 1. Equation of time Zgl over the year DIN 5034 Part 2 Page 3 Jan. Feb. Mar. Apr. May Jun. Jul. Aug. Sep. Oct. Nov. Dec. Figure 2. Declination of the sun 6 over the year J indicates 360“- JI365 or 5
20、1366. Zgl # = 0,0066 + 7,3525. COS COS (2. J + 1 08,s“) + + 85.9“) + 9,9359 . + 0,3387. cos (3. J + 105.29 cn = (0,3948 - 23,2559. cos (y + 9,iq - 0,391 5. . COS (2J + 5.49 - 0,1764. COS (3. J + 26,O)J“ For calculating the position of the sun it is necessary also to specify w = hour angle = (12.00h
21、- WOZ). 15“/h; p = geographical latitude of position of observer. The hour angle w is counted from the meridian as positive towards the afternoon and negative towards the morning. The following then applies for the height of the sun (7) (8) (9) ys = arc sin (cos w. cos (a. cos + sin rp. sin 6) (10)
22、and for the solar azimuth sin ys. sin rp - sin cos ys. cos rp as = 1 80“ - arc cos for WO2 12.00 h or as = 1 80“ + arc cos sin ys. sin rp - sin 6 cos YS cos (p for WOZ 12.00 h The method of counting for the solar azimuth (see figure 3) is North: as = Oo; East: as = 90“; South: as = 180“; West: as =
23、270“. Note. Other methods of counting than the system used here are found in the relevant literature. (12) Page 4 DIN 5034 Part 2 Zenith Nadir Figure 3. Designation of angles for specifying or determining the position of the sun Figures 4 to 6 show the variation of the altitude of the sun ys and the
24、 solar azimuth as as a function of the time of day and time of year for 54O, 51 and 48O latitude North, .e. for northern, central and southern Germany respectively. t wo2 20 h 18 16 225“ 14 210“ 195“ 12 1 80“ 165 10 150“ 135O 8 6 4 Jan. Feb. Mar. Apr. May Jun. Jul. Aug. Sep. Oct. Nov. Dec. Figure 4.
25、 Solar azimuth as and altitude of the sun ys for 54 latitude North (Northern Germany, Cuxhaven-Lbeck) as a function of time of year and time of day DIN 5034 Part 2 Page 5 I woz 225“ 210“ 150“ 135“ Jan. Feb. Mar. Apr. May Jun. Jul. Aus. Sep. Oct. Nov. Dec. Figure 5. Solar azimuth as and altitude of t
26、he sun ys for 51“ latitude North (Central Germany, Aachen-Cologne-Kassel) as a function of time of year and time of day 20 h 18 16 1 : woz 10 a 6 4 Jan. Feb. Mar. Apr. May Jun. Jul. Aug. Sep. Oct. Nov. Dec. 225“ 21 O“ 195“ 165 150“ 135O 180“ 1 Figure 6. Solar azimuth as and altitude of the sun ys fo
27、r 48“ latitude North (Southern Germany, Freiburg-Munich-Traunstein) as a function of time of year and time of day 4 Photometric principles In order to calculate the daylight illumination conditions in interiors, it is necessary to know the sky luminance values and the outdoor illuminance values. The
28、se magnitudes are specified for the various sky conditions. 4.1 Overcast sky The axisyrnrnetric luminance distribution of an overcast sky is described by 5: 1 + 2. cos e 3 L(e) = Lz or Lo4 = Lz . 1 + 2. shy is the luminance of points in the sky at an angle e from the zenith; is the luminance of poin
29、ts in the sky at an angle y from the horizon; is the angle between the point observed in the sky and the zenith; is the angle between the point observed in the sky and the horizon. Page 6 DIN 5034 Part 2 175 W/m* 150 125 I O0: 75 E, 50 25 0.- The zenith luminance L, is defined as (15) 9 7x LZ = -. (
30、300 + 21 000. sin YS). cd/m2= (1 23 +, 8594. sin YS) cd/m2. The horizontal illuminance E, outdoors with a clear horizon is dependent on the altitude of the sun ys (see equation (IO) and is defined as: E, = (300 + 21 000. sin ys). ix (16) Figure 7 shows the horizontal illuminance E, as a function of
31、time of day and time of year for 51O latitude North - - - - - Figure 7. Horizontal illuminance E, and horizontal irradiance E, with overcast sky for 51“ latitude North as a function of time of year and time of day The iliuminance on inclined surfacesEa,F (angle of inclination yF to the horizontal) c
32、onsists of a component emanating from the sky and a component reflected from the ground (6): If the reflectance of the ground e, is unknown, pu = 0,2 is to be used as an average value. 4.2 Clear sky A clear sky, as a light source, is always associated with the sun. The relative luminance distributio
33、n of a clear sky is described by 2: l - exp (- 0,32/cos e) . 0.856+ 16. exp (- 3 glrad) + 0,3. cos2g Lp/Lx = ,- 0,27385. 0,856+ 16.exp 1-3. (-)+0.3- 2 rad cos2 (?-)I 2 rad I - where (see also figure 8) Lp L, is the zenith luminance; E t7 t7 ys as ap is the luminance of point P of the sky; is the ang
34、le between the zenith and point P; is the angle between the sun and pointP; = arc cos (sin YS . cos e + cos is the altitude of the sun (see equation (IO) is the solar azimuth (see equation (1 1) or (12); is the azimuth of point P, counted as for as. sin e. COS jas DIN 5034 Part 2 Page 7 Solar meridi
35、an Figure 8. Angle designations for assessing the luminance distribution in a clear sky For the ratio of the horizontal illuminance from the sky EH to the zenith luminance Lz, the following applies: - 7,6752 + 6.1 096 . 1 O-* . ys - 5,9344 . 1 O-4 . ys2 - 1.601 8 . 1 O-4 . ys3 + 3,8082 , ys4 - EH LZ
36、 - -3,3126. 10-8.ys5+ 1,0343- lo-. ys6 (20) The horizontal illuminance values resulting from the sun Es, the sky EH and the sun and sky E, depend on the altitude sun ys 6,7: of the where KS KH Ea SR- m P/P o P/Po is the photometric radiation equivalent for sunshine as a function of the altitude of t
37、he sun ys is the photometric radiation equivalent for sky radiation = 125,4 m/W; (25) is the radiance of the extraterrestrial sunshine; is the product of the mean optical thickness of the clean, dry Rayleigh atmosphere and the relative optical air mass; = (0,Q + 9,4. sinys)- al is the air pressure c
38、orrection for = exp (-H/HR); (27) (26) H HR =8km; (28) TL is the height of the place of observation above sea level; is the Linke turbidity factor; see table 1 for values; is the transmittance of the atmosphere with respect to absorption = (0,506 - 1,0788. 1 O-2. TL) . (1,294 + 2,441 7. 1 O-2. ys -.
39、 3,973 . ys + 3,8034 . ys3 -2,2145. 1 O-. ys4 + 5,8332. 1 O- . YS) ; Page 8 DIN 5034 Part 2 Table 1. Mean monthly turbidity factors TL in the Federal Republic of Germany 9 Monthly mean of TL Month I I Maximum January February March April May June July August September October November Decem ber Annu
40、al mean 4.8 4.6 54 5,7 5.8 74 6,9 63 6,O 4.9 4.2 4.1 54 Mean 3.8 f 1 .O 4,2 f 1 ,I 4,8 ? 1.5 5,2 I 1,s 5.4 k 1.7 6,4 k 1,9 6,3 I 2,O 6,l 11.9 5,5 t 1.6 4.3 2 1.3 3,7 I 0,8 3.6 k 0,9 Minimum 4.9 I 1,5 4,7 Note. The following approximate formulae Es = 85 000. sin ys + 6500. sin (2 YS) . Lx and EH = 28
41、0. arc tan (YS/ : 18.9) . Lx can also be used and provide an accuracy normally sufficient for practical purposes. They apply for a mean turbidity of T = 4,9. Figure 9 shows tnese variations of the illuminance values as a function of the altitude of the sun. 3;- Figure 9. Horizontal illuminance Es fr
42、om the sun, EH from the sky and E,from the sun and sky, as a function of the altitude of the sun ys, with a clear sky and a (Linke) turbidity factor of TL = 4,9. The illuminance on inclined surfaces (this represents the interval during which the sun is not shining). A T , SSW = 24 min AT. (1 -SSW) =
43、36 min During the interval, AT. SSW, Em,F,S can be calculated as Em. F, s = Es, F ES . 0.5 . Qu . (1 - COS YF) . Rs (39) where eu YF ES,F Es Rs is the reflectance of the ground; is the inclination of the surface to the horizontal: is the illuminance produced directly by the sun on the inclined surfa
44、ce when the sky is clear; is the horizontal illuminance resulting from the sun when the sky is clear; is a correction factor for a partly overcast sky (used, inter alia, for taking account of systematic errors in recording duration of sunshine with a sunshine autograph recorder 6); = 1,48 - 4,07 . S
45、S W + 6,92 . SS W2 - 3,34 . SS W3. (40) During the interval A T. (1 - SSW), the following applies: Em,F,S = o (41) The component Em,F,H produced by the sky direct and by reflection from the ground in the case of an average sky is to be calculated from the relevant illuminance values for a clear sky
46、and an overcast sky and applies for the entire interval AT, .e. irrespective of whether the sun is shining or not. A division of the interval so as only to take account of the clear sky for the interval AT - SSW and only of the overcast sky for the interval AT (1 - SSW) is not possible, because the
47、average sky includes all sky conditions, in particular a partly overcast sky. A partly overcast sky. however, occurs both with and without sunshine. Em,F,H= (EH,F+ EH 095 eu (1 -cosYF) ssw+ E,F. (1 -ssw) RH (42) where EH.F EH Ea,p R, is the illuminance produced on the inclined surface direct from th
48、e sky when the sky is clear; is the horizontal illuminance produced by the sky when the sky is clear; is the illuminance produced on the inclined surface direct from the sky and by reflection from the earth with an overcast sky; is a correction factor for a partly overcast sky 6); = 1 + 2.54 I SS W
49、- 2,98. SSW2 + 0,444. SSW3. (43) DIN 5034 Part 2 Page 1 1 The illuminance in the case of an average sky on any inclined surfaces in the interval AT. SSW is then obtained as Em.F= Em, F, s + Em, F, H Em, F* = Em, F, H (44) The illuminance in the case of an average sky on any inclined surfaces in the interval AT . (1 - SSW) is obtained as (45) In order to calculate the period of use (.e. the number of hours of effective daylight), these two intervals and hence also Ern, and E,“ have always to b
