Ratio IV/D=Effective width of window to one side of normal: Distance from window
Table 1
SKY COMPONENTS (C.1.E. OVERCAST SKY) FOR VERTICAL GLAZED RECTANGULAR WINDOWS
Ratio H/D=Height of window above working plane: distance from window
0
0.J
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1.0
J.J
1.2
1.3
1.4
15
1.6
1.7
1.8
1.9 2.0 2.2
2.4
2.6
24
3.0
3.5
4.0
3.0
8
0.1
0
→
.0.1 0.1
0.2
0.2
0.3
0.4
0.5
0.6
0.6
0.7
0.8
0.8
0.9
0.9
0.9 1.0
1.0
1.0
11
1.1
1.1
I 1
1.2
1.2
1.2
1.2
#3
0.2
0
0.1
0.1 0.2
0.4
0.5
0.7
0.8
1.0
1.1
13
1.4
1.5
1.6
1.7
1.8
1.9
1.9
2.0
20
21
22 2.2
23
2.3
24
24
2.4
25
0.3
0
0.1
0.2
03
0.5
0.7
1.0
1.2
1.5
1.7
1.9
2.1
2.3
24 2.6
2.7
2.8
2.9
3.0
31
3.2
33
3.4
3.4
3.5
3.4
3.6 3.7 3.7
0.4
0
0.1
0.3 0.4
0.5
0
01
0.3
0.5
0.6
0.1
0.3 0.6
0.7
0
0.2
0.4
0.7
0.8
0.1
1.0
0.1
1.2
1.4
1.6
1.8
8 6 3 3
0.1
0.1
៩ ៩ ៩ ៩
0.4
0.7
0.4
0.8
0.4
0.8
05
0.9
0.2
0.5
0.9
0.1
0.2
0.9
0.1
2.0
01
222
0.5 0,9
0.2
0.5
10
ཊྛ ཋ ཋ ཋ - མུའ- ་ ་ ་
0.7
10
1.3
16
1.9
2.2
2.5
2.7
2.9
3.2
3.3
35
3.6
3.8
3.9
4.0
4.1
4.3
44
4.5
4.5
46 47 41
4.9
1.2
1.5
1.9
2.2
2.6
3.0
3.3
3.6
3.8
4.0
4.2
4.4
4.6
4.7
4.3 $.0
5.2
5.3
5.4
5.5
57
5.8 59
5.9
13
1.7
2.2 · 26
3.0
3.4
3.8
4.1
4.4
46 4.9
5.1
5.3
5.4
5.6 5.8 6.0
6.2
6.3
64
6.6
67 6.8 69
1.5
1.9
2.4 2.8
3.3
3.8
4.2
4.5
4.3
5.1
5.4
56
5.8
6.0
12
62
6.4
66
68 7.0 7.1 73
7.4 7.6
7.7
1.6
21
26
3.1
3.6
41 4.5
4.9
5.2
5.6
5.8
6.1
6.3
6.5
67
67
7.0
7.3 7.5 7.6 7.8
8.0
8.2
8.3
2.4
17
2.2
2.7
3.3
3.8
4.3
4.3
5.2
5.6
5.9
62
65
6.7 6.9 71 7.4
7.7 7.9 8.1
8.2
8.5
0.7
9.0
1.8
2.3 2.9
3.4
4.0
4.6
5.0 55 5.9 6.2
6.3
63
71 73 75
79
1
84
#6
87
9.0
9.2
9.4
9.6
1.9 2.5
3.1
3.7
4.3
4.9
5.4
5.9 6.4
6.8
72
7.5
71
1.1
-
83
87
91
93
9.6 9 8 10 1
10 3
10 3 10.7
19
2.5 32
3.8
4.5
51 $7
62
67
71
75
78
#2
85
0.7
9.1 9.5
98 100 10.2 106
109
|| 1
11.6
2.0 2.6
3.3 3.9
4.6
5.3 59 64
70
7.4
7.8
82
8.5
. 1
91
96 100
10.2 105 107 111
13.4 117 12.2
2.0 2.6
3.3 4.0
47
54 60 6.6
7.2
7.6
容量
85
**
9.2
95
10.0
10 4
10.1
|| | 113 118
120 123 126
0.2
1.0 0.5
15 2.0
2.6
3.3
4.0
47
54 61
67
73
78
82
$6 90
94
97 102
10.7
1! 1
114
117 122
124
12.7 130
2.5
3.0
0
3 3 3 3 84
B
0.1 0.2 0.5 1.0
0.1 0.2 0.5 1.0
1.5 2.1
1.5 2.1
2.6 3.3
4.0
40
5.5
62
6.8
74
79
84
8 &
9.2 96
9.9
10.5 110
114
117
120 126 129 133 13.7
זל
2.7 3.4 4.1
4.8 5.6
62
6.9
75
8.0
#.5 6.9 93 97
10.0 107 112 117 12.0 124 12.9 133 137 14 2
4.0 0.1 0.2 05 1.0
6.0 0.1 0.2 0.5
1.5
21
1.0 15 21 2.8
2.7
3.4 41
49
56
63
69
75
80 86 90
94
94
10 1 10.3. 11.3
122 125 132 13.5 140 14.6
34 4.2
5.0
5.7
63
6.9
7.6
81
24
91
95
0.1 0.2 0.5 1,0 1.5 2.1 28 3.4 4.2
5.0
5.7
63
7.0
76 81
9.1 16
11* 17° 22* 27*
31* 35* 39*
42°
45*
50*
52" 54' 56* 58'
60*
41*
9.5 99
62*
102 109 114 119
10.9 10.J
12.3 11.5 119
63*
67"
123 126 132 136 14 1 149
127 13.3 137 14.2 15.0
70* 72" 74" 76* 79"
Angle of obstruction
designers in this country. The pro- tractors are quicker to use than grid methods although they may not be so accurate when the obstructions and window are of complicated outline. For the majority of cases it is usually possible to assume an average simple outline for external obstructions with- out serious loss of accuracy.
The protractors are available as five pairs:
Nos. 1 and 2 for vertical glazing Nos. 3 and 4 for horizontal glaz-
ing
Nos. 5 and 6 for glazing sloping
at 30° to the horizontal Nos. 7 and 8 for glazing sloping
at 60° to the horizontal
Nos. 9 and 10 for unglazed aper
tures.
were
The protractors
designed originally for determining, from drawings, sky components from a sky of uniform luminance. The cor- rection for the luminance distribu- tion of an overcast sky can be made quite simply with the aid of Fig. 2, which gives the sky luminance ratios for various angles of altitude. Mul- tiplication of the protractor readings by the ratio for a particular angle gives the desired sky component.
Each pair of protractors consists of a basic protractor, graduated to give percentage sky components for windows of infinite length, and an
auxiliary protractor which gives the correction factor to be applied to these values for windows of finite length. The correction factor for a particular length of window varies with the average angle of altitude of the patch of visible sky and this is allowed for in the auxiliary protrac- tors by a series of concentric scales each corresponding to a particular angle of altitude.
Example Application of Protractors 1 and 2
Assume that the room being examined has one rectangular glazed window and that there is a long horizontal obstruction, parallel with the plane of the window (see Fig. 6).
70 %.
ALARENCE
PINT
118
Fig. 3. Ways in which daylight reaches indoor position
FLOOR LEVEL
simplified
Fig. 4. Application of B.R.S. daylight tables
THE HONG KONG & FAR EAST BUILDER-VOLUME 19. NUMBER 2
'ding Research Station Digest (2nd Series)—41
No comments yet.
Private notes are available after approval.