Interior Lighting for Designers

tube is called thewindow.Intensity of light
emitted through the window is significantly
increased; total light output is reduced, how-
ever. Except in special applications, regular
lamps in efficient luminaires perform better
(figure 7.7).

Compact fluorescent lamps
Compact fluorescentlamps provide high effi-
cacy, a CRI of 82, and 10,000- to 20,000-
hr lives in a single-ended, multi-tube fluores-
cent lamp (figure 7.8). They operate in the
preheat and rapid-start circuit modes; many
have a starter built into the lamp base.

Compact fluorescent lamps have signifi-

cantly higher lumen output per unit length

than conventional small fluorescent lamps.

This is the result of high phosphor loading,

which is necessary because of their small

diameter and sharp-cornered, multi-tube

bulb shape. As with all fluorescent lamps,

compact ones require a ballast in order to

start and operate properly.

The compact lamps use the same high-

color-rendering rare-earth phosphors as the

T5 and T8 lamps mentioned earlier. Color

temperature varies according to the relative

balance among the phosphors. The 2700 K

INTERIOR LIGHTING FOR DESIGNERS

Figure 7.7Reflector and aperture fluorescent lamps at one-half actual size.