Sylvania Dulux L 55W 3500K 4-Pin Compact Fluorescent Lamp – Natural White | 4800 Lumens | CRI 82 | 2G11 Base | 12,000 Hours | Code 20591

The Sylvania Code 20591 Dulux L is a 55-watt 3500K natural white long twin tube compact fluorescent lamp delivering 4,800 initial lumens with CRI 82, 2G11 4-pin base, and 12,000-hour rated life. Compatible with magnetic, electronic, and dimming ballasts, this lamp is a direct form-factor equivalent to the 4100K Dulux L 55W for applications specifying 3500K natural white output in 2G11 base commercial and institutional fixtures.

Quick Specs

• Brand: Sylvania
• Series: Dulux L
• Code: 20591
• Lamp Type: Long Twin Tube Compact Fluorescent (T5 × 2)
• Wattage: 55W
• Color Temperature: 3500K (Natural White — 835)
• CRI: 82
• Initial Lumens (at 25°C): 4,800 lm
• Mean Lumens (at 25°C): 4,128 lm
• Rated Average Life: 12,000 hours
• Base: 2G11 (4-Pin)
• Bulb Type: Twin Tube (T5 × 2)
• Overall Length (MOL): 21.1 inches (535mm)
• Diameter: 0.709 inches (18mm)
• Ballast Compatibility: Magnetic, electronic, or dimming ballast

Product Overview

The Sylvania Dulux L 55W 3500K  is a 55-watt long twin tube compact fluorescent lamp in the 2G11 4-pin format — the 3500K natural white variant of the Sylvania Dulux L 55W platform. Producing 4,800 initial lumens at 3500K with CRI 82 and a 12,000-hour rated life, this lamp is specified for commercial and institutional 2G11 fixture applications where natural white color temperature is preferred over the cooler 4100K alternative.

3500K natural white sits between warm white (3000K) and cool white (4100K) — producing a balanced, comfortable light quality suited for offices, healthcare facilities, retail environments, and hospitality spaces where 4100K feels too clinical. All other specifications are identical to the 4100K Dulux L 55W (Code 20592): same wattage, base, dimensions, ballast compatibility, and rated life. When replacing existing lamps, verify the installed color temperature before ordering to ensure consistency across the fixture installation.

The 2G11 4-pin base requires an external ballast — this lamp is not self-ballasted. Life ratings are based on 3-hour burning cycles with ANSI-compliant ballasts. Initial lumens (4,800 lm) are measured after 100 hours of operation. Mean lumens (4,128 lm) are measured at 40% of rated lamp life.

Why Choose This Product

• 3500K natural white — balanced commercial color temperature: Neither the warmth of 3000K nor the clinical coolness of 4100K — the preferred specification for mixed-use offices, healthcare corridors, retail environments, and hospitality spaces where comfortable, neutral light quality is required.
• 4,800 initial lumens at 55W: Full high-output Dulux L lumen performance at 3500K — same output as the 4100K version with a warmer color quality.
• CRI 82 — good color rendering: Above the 70-series standard, appropriate for commercial and institutional environments where color accuracy supports task performance and occupant comfort.
• 12,000-hour rated life: Long service life reduces replacement frequency and maintenance cost in large commercial lamp installations.
• Magnetic, electronic, and dimming ballast compatibility: Works with virtually all 55W 2G11 ballast types — same ballast compatibility as the 4100K Dulux L 55W, so no ballast change is required when switching color temperature within the same Dulux L platform.
• Same dimensions and base as Dulux L 4100K: Physical drop-in replacement in any fixture currently running 55W 2G11 lamps — no fixture modification required when switching from 4100K to 3500K for a color temperature upgrade or correction.

Technical Specifications

Replacement Ballasts for 55W 2G11 Lamps

The following ballast models are compatible with this lamp and the full Sylvania Dulux L 55W platform:

Always verify ballast ANSI code and rated lamp compatibility before ordering a replacement ballast.

Applications

The Sylvania Dulux L 55W 3500K is specified for 2G11 CFL fixture applications where natural white color temperature is preferred over cool white:

• Commercial offices and mixed-use workspaces – 3500K natural white is widely specified for offices where 4100K feels too clinical — provides comfortable, balanced illumination for desk tasks, reception areas, and conference rooms.
• Healthcare facilities – 3500K is appropriate for patient waiting areas, corridors, and clinical support spaces where a warmer feel than 4100K is preferred without sacrificing light output.
• Retail environments – Natural white enhances merchandise appearance for apparel, home goods, and general retail without the blue-shift of cool white sources.
• Hospitality and institutional buildings – Hotels, schools, and institutional facilities where 3500K balanced light quality supports visual comfort for occupants across extended periods.
• Color temperature upgrades – Installations currently running 4100K Dulux L 55W lamps where a shift to 3500K is required — direct physical replacement with no ballast or fixture change needed.

Ballast Compatibility and Installation Notes

• 4-pin 2G11 base — requires external ballast: This lamp is not self-ballasted. Verify your fixture’s ballast type (magnetic, electronic, or dimming) before ordering.
• Life rating basis: 12,000-hour rated life is based on 3-hour burning cycles with ANSI-compliant ballasts. Longer operating cycles extend lamp life.
• Initial lumens: 4,800 lm is measured after approximately 100 hours of operation. Mean lumens (4,128 lm) are measured at 40% of rated average lamp life.
• Minimum starting temperature: Depends on ballast type — consult the ballast manufacturer’s specification sheet.
• NEMA end-of-life notice: T5 compact fluorescent lamps on high-frequency ballasts may experience an abnormal end-of-life phenomenon resulting in bulb wall cracking near the base or base area overheating. NEMA recommends high-frequency CFL ballasts include an end-of-life shutdown circuit. See NEMA.org for additional information.
• Color temperature consistency: If replacing lamps in a multi-lamp installation, replace all lamps with the same color temperature (3500K) to maintain consistent light quality across the space.

Ordering Information

• Brand: Sylvania
• Code: 20991
• Series: Dulux L
• Lamp Type: 55W Long Twin Tube CFL
• Color Temperature: 3500K Natural White
• Base: 2G11 4-Pin
• Case quantities and bulk pricing: Contact ADL Supply for volume orders.

Compliance

• Verify RoHS / TCLP / California Title 20 compliance with manufacturer specification sheet.
• This lamp contains mercury — dispose per local lamp recycling regulations. Visit lamprecycle.org.

ADL Supply recommends confirming all compliance data with the Sylvania official product data sheet prior to installation.