Sylvania 20594 FT18DL/835/RS/ECO

Sylvania 20594 FT18DL/835/RS/ECO – 18W Dulux® L ECOLOGIC® Twin-Tube CFL | 1,250 lm | 3500K | 82 CRI | 2G11 4-Pin | Rapid Start | TCLP Compliant

The Sylvania 20594 (FT18DL/835/RS/ECO) is an 18W Dulux® L ECOLOGIC® twin-tube compact fluorescent lamp with a 2G11 4-pin base and Rapid Start (RS) designation, delivering 1,250 lumens at 3500K (Natural White) with 82 CRI. This is a single-ended T5-profile twin-tube CFL compatible with magnetic, electronic, and dimming ballasts. ECOLOGIC® reduced-mercury technology (3.0 mg) meets federal TCLP criteria for non-hazardous waste classification. The FT18DL and FT18DL/RS are not electrically interchangeable — this is the RS version; confirm the correct ordering code matches your ballast before purchasing. Please verify base type and ballast compatibility before ordering.

Technical Specifications

Product Overview

The Sylvania 20594 (FT18DL/835/RS/ECO) is the Rapid Start (RS) version of the 18W Dulux® L ECOLOGIC® twin-tube CFL at 3500K. The RS designation is critical for ordering: the FT18DL and FT18DL/RS are explicitly identified by Sylvania as not electrically interchangeable. They share the same 2G11 4-pin base and physical form factor but are wired differently internally for their respective starting methods. Installing the wrong version in a fixture wired for the other will result in incorrect operation or non-starting.

At 1,250 lumens from 18W at 3500K and 82 CRI, the lamp provides neutral-white light in a compact twin-tube T5-profile envelope suited to indirect fixtures, wall sconces, recessed downlights, surface-mounted luminaires, landscape lighting, signage, and task lighting. The 3500K color temperature sits between the warm 3000K (830) and cool 4100K (841) options in the family, offering a balanced neutral white commonly specified in offices and commercial interiors.

The ECOLOGIC® designation indicates reduced mercury content (3.0 mg) meeting federal TCLP criteria for non-hazardous waste classification, simplifying disposal compliance. NEMA recommends using high-frequency ballasts equipped with end-of-life (EOL) shutdown circuits to safely prevent overheating of the lamp base and socket in the rare event of an abnormal end-of-life failure.

Compatible Applications

• Indirect fixtures and cove lighting
• Wall sconces and wall washing
• Recessed and surface-mounted fixtures with 2G11 sockets
• Landscape lighting
• Signage and display backlighting
• Task lighting

Before Ordering – Verify

• RS version — FT18DL and FT18DL/RS are not electrically interchangeable. This is the RS (Rapid Start) version (NAED 20594). The non-RS version (NAED 20587, FT18DL/830/ECO) is a different lamp with a different internal wiring configuration. Confirm which version the ballast requires before ordering.
• Base: 2G11 (4-pin). Confirm the fixture socket is specifically 2G11.
• Ballast: Compatible with magnetic, electronic, and dimming ballasts rated for 18W 2G11 Dulux L RS lamps. Reported compatible ballasts (from existing listing, unverified): Sylvania 51833 QTP2x26CF/UNV DM; Universal Triad CT218UNVME.
• CCT: This lamp is 3500K (835, Natural White). The Dulux L ECO family is also available in 3000K (830) and other CCTs.
• Overall length: 267mm (10.51″). Confirm the fixture accommodates this length — note this is longer than the non-RS 830 sibling (214.5mm / 8.44″).
• NEMA recommends using ballasts with end-of-life (EOL) shutdown circuits for safe operation.

Safety and Handling Guidelines

• This lamp contains mercury (3.0 mg, ECOLOGIC®). If broken, ventilate the area and follow EPA fluorescent lamp breakage cleanup guidelines; do not vacuum broken pieces
• Recycle through a designated lamp recycling program per applicable local, state, and federal regulations
• Disconnect power before installing or replacing the lamp
• NEMA recommends ballasts with EOL shutdown circuits to prevent overheating in the event of abnormal end-of-life lamp failure

Compliance

• ECOLOGIC® — meets federal TCLP criteria for non-hazardous waste classification (3.0 mg Hg)
• Contains mercury — dispose of per local, state, and federal regulations
• 2G11 4-pin base; Rapid Start (RS) version

Ordering Information

• NAED: 20594
• Ordering Abbreviation: FT18DL/835/RS/ECO
• UPC: 0046135205941
• Case Quantity: 10 per case
• Non-RS 830 sibling: 20587 (FT18DL/830/ECO) — not interchangeable

For wholesale pricing, bulk availability, or help confirming the correct replacement lamp, contact ADL Supply at 1-800-235-3489.