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What T5 lamps are available?
T5 lamps are available for standard output and high output. The wattages for standard T5 lamps are 14, 21, 28, and 35 watts. The high-output T5 (T5 HO) lamps are available in 24, 39, 54, and 80 watts (49-watt T5 HO lamps are also available from GE Lighting). Table 1-2 summarizes the features of the standard T5 and T5 HO lamps available in the United States. A four-foot long, 54-watt version that delivers 5,000 lumens is popular in the United States. The high light output allows fewer luminaires to achieve the same illuminance levels as when using other fluorescent lamps. As Table 1-2 shows, however, T5 HO lamps are slightly less efficacious than standard T5 lamps.
Table 1-3 illustrates features of four-foot standard T8 and T12 lamps. Standard T5 and T5 HO lamps have a rated average lamp life of 20,000 hours, the same as most standard T8 and T12 lamps. New prolonged-life T8 and T12 lamps have lives of 4,000 to 10,000 hours longer than T5 lamps. (Table 1-3 excludes these lamps.) The lamps in Table 1-2 all use RE80, a rare earth phosphor with a color rendering index (CRI) value of 85.
Table 1-2. T5 and T5 HO Lamps |
(From manufacturers' catalogs; Philips Lighting 2001/2002; GE Lighting 2001/2002) |
|
Lamp Type |
Nominal Length |
CCT |
Light Output* (lm) |
Lamp Efficacy** |
|
(in) |
(K) |
|
(lm/W) |
|
Initial |
Mean |
|
|
T5 14W |
22 |
3,000-6,500 |
1,350 |
1,269-1,275 |
96 |
T5 21W |
34 |
3,000-6,500 |
2,100 |
1,974-2,000 |
100 |
T5 28W |
46 |
3,000-6,500 |
2,900 |
2,726-2,750 |
104 |
T5 35W |
58 |
3,000-6,500 |
3,650 |
3,431-3,450 |
104 |
|
T5 HO 24W |
22 |
3,000-6,500 |
2,000 |
1,880-1,895 |
83 |
T5 HO 39W |
34 |
3,000-6,500 |
3,500 |
3,290-3,320 |
90 |
T5 HO 54W |
46 |
3,000-6,500 |
5,000 |
4,700-4,740 |
93 |
T5 HO 80W |
58 |
3,000-6,500 |
7,000 |
6,580-6,650 |
88 |
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Table 1-3. Four-Foot T8 and T12 Lamps |
(From manufacturers' catalogs; Philips Lighting 2001/2002; GE Lighting 2001/2002) |
|
Lamp Type |
Nominal Length |
Phosphor* |
CCT |
CRI |
Light Output** (lm) |
Lamp Efficacy** |
|
(K) |
|
|
|
(in) |
|
Initial |
Mean |
(lm/W) |
|
T12 40W |
48 |
RE70 |
3,000-6,500 |
70-75 |
3,050-3,250 |
2,775-2,950 |
81 |
|
48 |
RE80 |
3,000-5,000 |
80-82 |
2,200-3,400 |
1,775-3,090 |
85 |
|
T12 34W |
48 |
RE70 |
3,000-6,500 |
70-75 |
2,650-2,800 |
2,430-2,520 |
82 |
|
48 |
RE80 |
3,000-5,000 |
80-82 |
2,025-2,900 |
1,775-2,610 |
85 |
|
T8 32W |
48 |
RE70 |
3,000-6,500 |
75-78 |
2,700-2,850 |
2,550-2,710 |
89 |
|
48 |
RE80 |
3,000-5,000 |
86 |
2,800-2,950 |
2,660-2,800 |
92 |
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