How to find the right Fluorescent Lamps AI guide
Written by an AI model from its trained knowledge.
What the AI looks for in Fluorescent Lamps
- Tube diameter and base
- T8 and T12 tubes use the G13 bi-pin base. T5 tubes use the smaller G5 base and are a different length. Match the T-size printed on the old tube. T8 and T12 tubes fit the same sockets but need different ballasts. T5 tubes do not fit those sockets at all.
- Ballast match
- T8 tubes need an electronic T8 ballast. T12 tubes run on magnetic or T12 ballasts. The ballast label lists the lamp types it supports. A tube on the wrong ballast flickers, starts slowly, or dies early.
- CFL pin type
- 2-pin plug-in CFLs (G23/G24d family) contain a starter and run on magnetic ballasts. 4-pin CFLs (G24q/GX24q family) need an electronic ballast. Plug-in CFLs with similar shapes are not interchangeable across pin counts.
- Color code
- The three-digit color code (e.g. 841, 850): the first digit is the color rendering class and the last two are the color temperature in hundreds of kelvin. This makes replacement tubes easy to match to the ones already installed.
- Length and wattage
- Match nominal length and wattage. Reduced-wattage energy-saver T8s may not start below about 60°F or on dimming ballasts. Energy-saver tubes fail in cold spaces and on some ballasts.
Brands that matter
- Philips (Signify): Alto low-mercury tubes are widely specified.
- Sylvania / LEDVANCE: Octron T8 and Pentron T5 lines.
- GE: Long-standing fluorescent tube maker.
- Ushio: Specialty and aquarium/plant fluorescent tubes.
- Satco: Good source of plug-in CFL replacements.
What to avoid
- Running T8 tubes on old T12 magnetic ballasts.
- Throwing used tubes in household trash; they contain mercury and many areas require recycling.
- Energy-saver tubes in unheated garages or on dimming ballasts.
Questions
Can I put an LED tube in my fluorescent fixture?
Type A LED tubes run on the existing ballast if it is on the tube's compatibility list. Type B tubes need the ballast removed and the sockets rewired to line voltage.