Certified Energy Auditor Practice Exam

Reducing voltage in general lighting systems typically leads to a color shift in the emitted light. This shift occurs because different light sources, particularly incandescent and fluorescent lamps, respond variably to lower voltage levels. For incandescent lamps, reducing the voltage causes the filament to operate at a lower temperature, resulting in a warmer color temperature and a shift towards red hues. Similarly, for fluorescent lamps, a drop in voltage can affect the ionization process, potentially altering the color spectrum of the light emitted. Although reduced brightness might seem like a potential effect of lower voltage, it is more nuanced; while light output does decrease, the primary change is in the color of the light rather than an overall reduction in visual effectiveness. Hence, the most direct and significant consequence of lowering voltage in these systems is indeed the color shift.