Product Overview
Sylvania 20921 FP21/835/ECO 21W T5 3500K Neutral White Fluorescent Lamp
The Sylvania 20921 (FP21/835/ECO) is a 21W T5 miniature bi-pin (5/8" diameter) linear fluorescent lamp from the PENTRON High Performance ECOLOGIC series. It measures 34.0" in overall length and produces 3500K neutral white light with an 85 CRI. Rated average life is 20,000 hours based on 3-hour starts, extending to 22,000 hours on 12-hour starts.
Wattage 21W T5 | Color Temp 3500K Neutral White | Lumens 1,900 Initial @ 25°C | Length 34.0" 36" Nominal | Rated Life 20,000 Hours (3hr starts) |
Technical Specifications
| Sylvania Product Number | 20921 |
| Ordering Abbreviation | FP21/835/ECO |
| Series | PENTRON High Performance ECOLOGIC |
| Bulb Type | T5 Miniature Bi-Pin (5/8" diameter) |
| Base | G5 Mini Bi-Pin |
| Wattage | 21W |
| Nominal Length | 36" |
| MOL (Maximum Overall Length) | 34.0" |
| Color Temperature | 3500K (Neutral White) |
| CRI | 85 |
| Initial Lumens @ 25°C/77°F | 1,900 (mean 1,765) |
| Initial Lumens @ 35°C/95°F | 2,100 (mean 1,955) |
| Average Rated Life (3hr starts) | 20,000 hours |
| Average Rated Life (12hr starts) | 22,000 hours |
| Standard Package Quantity | 40 per case |
| Mercury Content | Contains mercury – not for sale or shipment in CA, CO, HI, ME, MN, OR, RI, VT; recycle per lamprecycle.org |
Product Overview
The Sylvania 20921 is part of the PENTRON High Performance ECOLOGIC lineup, built on the 5/8" diameter T5 miniature bi-pin platform. ECOLOGIC® designates Sylvania's reduced-mercury-dose fluorescent formulation, and this lamp is rated at 20,000 hours average life on 3-hour starts (up to 22,000 hours on 12-hour starts), with 3500K color temperature and 85 CRI for consistent, accurate color rendering.
Lumen output is rated at two ambient temperatures – 1,900 lumens at 25°C/77°F and 2,100 lumens at 35°C/95°F – since T5 fluorescent output varies with the operating temperature inside the fixture. Use the 35°C figure for enclosed or high-ambient-temperature fixtures.
Compatible Applications
- Fixtures specified for a 21W T5 G5 mini bi-pin lamp at 34.0" length
- Commercial, retail, and office linear fluorescent fixtures using T5 lamps
- Direct replacement for the Sylvania 20921 or its FP21/835/ECO ordering abbreviation
Before Ordering – Verify
- Confirm your fixture accepts a 21W T5 lamp with a G5 mini bi-pin base
- Confirm lamp length of 34.0" matches your fixture's socket spacing
- Confirm the ballast is compatible with T5 lamps of this wattage
- Confirm 3500K color temperature matches the rest of your installation
Safety and Handling Guidelines
- Turn off and allow the fixture to cool before relamping
- Handle by the base/end caps; avoid flexing or striking the glass tube
- Contains mercury – if broken, ventilate the area and follow EPA cleanup guidance
- Dispose of / recycle in accordance with state and local regulations
Compliance
- Contains mercury – not for sale or shipment in CA, CO, HI, ME, MN, OR, RI, VT
- Recycle per lamprecycle.org
Ordering Information
- Sylvania Product Number: 20921
- Ordering Abbreviation: FP21/835/ECO
- Manufacturer Part Number: FP21/835/ECO
- UPC: 046135209215
- Standard Package Quantity: 40 per case
For wholesale pricing, bulk availability, or help confirming the correct replacement lamp, contact ADL Supply at 1-800-235-3489.
