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How is performance affected by ambient temperature?
Performance characteristics of high-wattage compact fluorescent lamps (HW-CFL) will be affected by lamp base position and by operation in cold or hot environments. Temperature impacts both short-term and long-term performance. In the short-term, temperature impacts HW-CFL light output, electric power, and luminous
efficacy, with most lamps operating at their peak in an ambient temperature of about 77°F (25°C). Over long periods of time, elevated temperatures may shorten ballast life and consequently reduce lamp life in self-ballasted HW-CFLs.
Short-term thermal effects
Operating fluorescent lamps in cold or hot environments will lead to reduced light output, reduced power, and reduced efficacy, as shown in Figure 9. (Note: This graph is not specific to HW-CFLs.)
Figure 9. Impact of ambient temperature on power, light output, and efficacy of many fluorescent lamps |
 °F = (°C x 1.8) + 32 |
Adapted from: Bleeker and Veenstra, 1990 |
Some manufacturers of HW-CFLs report information about light output at a range of temperatures (see How does lamp orientation affect performance of HW-CFLs?). If this information is not available, users can generalize from other curves showing fluorescent output for minimum bulb wall temperature or ambient temperature, such as Figure 9.
As shown in Figure 10, reduction in light output can be minimized with the use of a mercury amalgam. (Note: This graph is not specific to HW-CFLs.) Use of mercury amalgam with HW-CFLs is often not reported in lamp catalog information. However, users can request this information from the lamp manufacturer. NLPIP obtained this information for products on the market (at the time of publication) and listed the results under “Mercury Type” in Table 7 and Table 8 (see What HW-CFL products are available?).
Figure 10. Impact of ambient temperature on light output of amalgam and nonamalgam fluorescent lamps |
 °F = (°C x 1.8) + 32 |
Rea MS (ed.). 2000. IESNA Handbook, ninth edition. 6-43.
New York: Illuminating Engineering Society of North America. |
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