8.) We have a two Room comparison for this problem with Room A and Room B: Room A: Room A measures 18’ x 18’ in plan ar
Posted: Mon May 16, 2022 12:35 pm
8.) We have a two Room comparison for this problem with
Room A and Room B:
Room A: Room A measures
18’ x 18’ in plan area with a ceiling height of 9.7 feet (plan view
similar to (g) in Figure 19.8 (Text 6th Edition Page
426; Text 5th Edition Figure 17.7 Page 455). For
purposes of this problem only, assume that each gridded square in
Plan (k) in your class text represents 2 feet by 2 feet.
Therefore, Room A is 9 squares or 18’ x 9 squares or 18’ and with
each square at 2’ in length and width, this shows that the
fluorescent luminaires are at 2’ x 2’ square as well. These
single-lamp fluorescents are 34-watt with 2200-lumen bulbs.
The workplane height is at 2-1/2 feet (For CU numbers see Table 2
below). The light fixtures will be recessed in the
ceiling. The reflectances are 80% ceiling; 50% walls, and 20%
floor.
Room B:
Room B measures (plan view similar to (e) in Figure 19.9 (Text
6th Edition Page 427; Text 5th Edition Page
456). For purposes of this problem only, assume that each
gridded square in Plan (e) in your class text represents
approximately 5 feet by 5 feet. Therefore, Room B is 4
squares or 20’ in width x 19 squares or 95’ in length and with each
square at 5’ in length and width, this shows that the fluorescent
luminaires are at 5’ in length as well. [Note that in
order to have both Room A and Room B with the same plan view areas,
the lengthwise dimension of Room B was slightly stretched out to 95
feet.]
Like Room A, Room B will also have fluorescent luminaires that
are at 5’ in length as well. These though will be TWO-BULB
fluorescents are with each bulb at 2900-lumen bulbs and at
34-watts/bulb. The Room B ceiling height and workplane height
is the same as for Room A (For CU numbers see Table 2 below).
The light fixtures will be recessed in the ceiling. The
reflectances are 80% ceiling; 50% walls, and 20% floor.
Table 2: Coefficient of Utilization – All floor
reflectances = 20%
RCC%
80
80
80
70
70
70
50
50
RW%
70
50
30
70
50
30
50
30
RCR
0
.97
.97
.97
.94
.94
.94
.90
.90
1
.89
.86
.82
.87
.84
.81
.80
.78
2
.82
.76
.71
.80
.74
.70
.71
.68
3
.75
.67
.61
.73
.66
.61
.64
.59
4
.69
.60
.54
.68
.59
.53
.57
.52
5
.64
.54
.47
.62
.53
.47
.52
.46
6
.59
.49
.42
.58
.48
.42
.47
.41
7
.55
.45
.38
.54
.44
.38
.43
.37
8
.51
.41
.34
.50
.40
.34
.39
.34
9
.48
.38
.31
.47
.37
.31
.36
.31
10
.45
.35
.29
.44
.34
.28
.34
.28
(a) (b) (c) (d) (e) ( Ο Ο Ο Ο Ο. (g) (h) (k)
Room A and Room B:
Room A: Room A measures
18’ x 18’ in plan area with a ceiling height of 9.7 feet (plan view
similar to (g) in Figure 19.8 (Text 6th Edition Page
426; Text 5th Edition Figure 17.7 Page 455). For
purposes of this problem only, assume that each gridded square in
Plan (k) in your class text represents 2 feet by 2 feet.
Therefore, Room A is 9 squares or 18’ x 9 squares or 18’ and with
each square at 2’ in length and width, this shows that the
fluorescent luminaires are at 2’ x 2’ square as well. These
single-lamp fluorescents are 34-watt with 2200-lumen bulbs.
The workplane height is at 2-1/2 feet (For CU numbers see Table 2
below). The light fixtures will be recessed in the
ceiling. The reflectances are 80% ceiling; 50% walls, and 20%
floor.
Room B:
Room B measures (plan view similar to (e) in Figure 19.9 (Text
6th Edition Page 427; Text 5th Edition Page
456). For purposes of this problem only, assume that each
gridded square in Plan (e) in your class text represents
approximately 5 feet by 5 feet. Therefore, Room B is 4
squares or 20’ in width x 19 squares or 95’ in length and with each
square at 5’ in length and width, this shows that the fluorescent
luminaires are at 5’ in length as well. [Note that in
order to have both Room A and Room B with the same plan view areas,
the lengthwise dimension of Room B was slightly stretched out to 95
feet.]
Like Room A, Room B will also have fluorescent luminaires that
are at 5’ in length as well. These though will be TWO-BULB
fluorescents are with each bulb at 2900-lumen bulbs and at
34-watts/bulb. The Room B ceiling height and workplane height
is the same as for Room A (For CU numbers see Table 2 below).
The light fixtures will be recessed in the ceiling. The
reflectances are 80% ceiling; 50% walls, and 20% floor.
Table 2: Coefficient of Utilization – All floor
reflectances = 20%
RCC%
80
80
80
70
70
70
50
50
RW%
70
50
30
70
50
30
50
30
RCR
0
.97
.97
.97
.94
.94
.94
.90
.90
1
.89
.86
.82
.87
.84
.81
.80
.78
2
.82
.76
.71
.80
.74
.70
.71
.68
3
.75
.67
.61
.73
.66
.61
.64
.59
4
.69
.60
.54
.68
.59
.53
.57
.52
5
.64
.54
.47
.62
.53
.47
.52
.46
6
.59
.49
.42
.58
.48
.42
.47
.41
7
.55
.45
.38
.54
.44
.38
.43
.37
8
.51
.41
.34
.50
.40
.34
.39
.34
9
.48
.38
.31
.47
.37
.31
.36
.31
10
.45
.35
.29
.44
.34
.28
.34
.28
(a) (b) (c) (d) (e) ( Ο Ο Ο Ο Ο. (g) (h) (k)