Retrotec USACE - Manual (Page 229)

Appendix D D99
There are some LED retrofi t kits for exit signs, but the cost of new LED
exit signs are now quite competitive and it might be best just to replace the
existing fl uorescent or incandescent exit sign with new LED signs. The more
you get of these, the lower the cost per unit, so why not change them all to
maximize savings on the overall electric bill?
Figure D156. Non-LED exit sign (left); LED exit sign (right).
D.5.15 Using High-Pressure Sodium Lighting in Indoor
Environments (Ineffi ciency)
Figure D157. High-pressure sodium lighting
(left side of image); high output T8 (right side
of image).
Replace high-pressure sodium lighting with high color temperature lighting
and save approximately 50% in energy costs (Figure D157). High-pressure
sodium (HPS) lighting is not good lighting for interior applications. The color
rendition is terrible, and it is not good for performing visual tasks due to its
very low color temperature and CRI. Recent studies have shown that lamps
with higher color temperatures and CRIs provide better vision and allow for
reducing energy input while maintaining equal vision. In the case of HPS light-
ing, the color properties are so bad that equivalent vision can be obtained using
high color temperature fl uorescent lighting, such as the 850 (high CRI, 5000K)
lamps or metal halide lighting (typically 3900–4200K). The improvement in