Sylvania 67500 - LU35 HPS 35W High Pressure Sodium Bulb

The Sylvania LU35 is a 35-watt High Pressure Sodium lamp producing 2,250 initial lumens at a correlated color temperature of 1900 Kelvin — the lowest CCT of any mainstream lamp technology. That deep amber output is not a flaw but a defining characteristic of HPS chemistry: the sodium vapor discharge is efficient, long-lived, and highly stable, but the narrow spectral emission produces a CRI of just 22. To put that in context, a CRI-80 LED renders colors with reasonable fidelity; at CRI 22, the LU35 renders the world in monochromatic amber. What it lacks in color accuracy it compensates for in efficacy — approximately 64 lumens per watt — and longevity, with a 16,000-hour rated life that minimizes maintenance cycles in continuously operated fixtures.

The LU35 belongs in applications where continuous illumination, long lamp life, and operating cost are the primary criteria, and color rendering is irrelevant: parking structures, perimeter security lighting, roadway fixtures, and industrial yard lighting. The E26 medium base and universal burn position rating give it wide fixture compatibility within HPS-rated luminaires, but it requires an S76-coded ballast — a hard requirement that limits it to dedicated HPS fixtures. It is not a lamp for studios, retail display, or any environment where the human eye needs to distinguish colors. For facilities managers and maintenance teams running HPS infrastructure, the LU35 is a proven, cost-effective source that prioritizes uptime and operating economics over spectral quality.