LED bulbs
Light-emitting diode bulbs produce light by passing current through a semiconductor junction. They are the current standard for almost every residential and commercial application.
Key specifications
| Property | Typical value |
|---|---|
| Efficacy | 60–150 lm/W |
| Lifespan | 15,000–50,000 hours rated |
| CRI | 80+ standard; 90+ high-CRI; 95+ premium |
| Color temperature range | 2700 K, 3000 K, 4000 K, 5000 K, 6500 K |
| Warm-up time | Instant — full brightness at switch-on |
| Mercury | None |
| Heat output | Low — most heat dissipates via heatsink/base |
Color temperature guide
| Temperature | Appearance | Best for |
|---|---|---|
| 2700 K | Warm white — matches incandescent | Living rooms, bedrooms, restaurants |
| 3000 K | Soft white — slightly cooler | Kitchens, bathrooms, reading lamps |
| 4000 K | Neutral / cool white | Offices, garages, workshops |
| 5000 K | Daylight | Task lighting, art studios, detail work |
| 6500 K | Cool daylight / blue-white | Commercial displays, security lighting |
Lumen equivalents — replacing incandescent
| Old incandescent | Lumens needed | LED wattage |
|---|---|---|
| 40 W | ~450 lm | 5–6 W |
| 60 W | ~800 lm | 8–10 W |
| 75 W | ~1,100 lm | 11–13 W |
| 100 W | ~1,600 lm | 14–18 W |
| 150 W | ~2,600 lm | 22–26 W |
Dimmability
Most LED bulbs are dimmable, but require an LED-compatible dimmer switch. Standard incandescent dimmers (TRIAC/leading-edge) cause buzzing, flickering, and early failure with many LEDs. Replace with a trailing-edge or ELV dimmer rated for LED loads. Non-dimmable LED bulbs will fail quickly on any dimmer.
CRI guide
- CRI 80+ — acceptable for general home use
- CRI 90+ — recommended for kitchens, bathrooms, art spaces
- CRI 95+ — photography, retail display, medical
When buying: look at lumens (brightness), color temperature (K), CRI, and whether the bulb is labeled dimmable. The watt number on an LED package is power consumption, not brightness.