LED vs Incandescent: What Installers Should Spec — and What to Tell the Client
For anyone speccing lighting professionally, the LED-versus-incandescent question is settled. The useful questions are narrower: where the cost actually breaks even on a job, which spec lines prevent callbacks, and how to handle a client attached to the warm glow of a filament. Here’s the working answer for permanent, landscape, and holiday installs.
LED vs incandescent: what’s the difference?
The difference is in how each one makes light. An incandescent bulb heats a filament until it glows, so most of the energy leaves as heat — incandescent bulbs lose about 90% of their input to heat, according to the U.S. Department of Energy. An LED passes current through a semiconductor that emits light directly, with very little waste. That’s why LEDs use at least 75% less energy and last up to 25 times longer than incandescent.
| Feature | LED | Incandescent |
|---|---|---|
| Power for the same brightness (~800 lumens) | ~9 watts | ~60 watts |
| Lifespan | 25,000–50,000 hours | 1,000–2,000 hours |
| Replacements over ~25,000 hrs | About 1 | 12–25 |
| Heat | Runs cool | Runs hot |
| Color options | Warm to daylight (2200K–5000K+) | Warm only (~2700K) |
| Cost | Higher upfront, lower over its life | Lower upfront, higher over its life |
Are LEDs brighter than incandescent? Not inherently — brightness is measured in lumens, not watts. An LED just produces the same lumens at a fraction of the wattage, which is why a low-wattage LED replaces a much higher-wattage incandescent. “Brighter” is a spec you choose by lumen output, not a property of the technology.
cost that matters is relamping labor, not the bulb
Costs only look close on the shelf. Over the life of an install they aren’t — and the deciding number isn’t the energy bill, it’s relamping labor. On embedded, high, or sealed fixtures (soffit runs, recessed cans, permanent channel), sending a tech back to swap a $2 incandescent bulb every 1,000–2,000 hours dwarfs the bulb itself. A quality LED runs 25,000–50,000 hours, so those cycles mostly disappear — which is exactly why federal purchasing guidance counts longer lamp life as a labor saving, not just an energy one. Quote the job on LED and the callback math goes away.
How to spec LED so it doesn’t come back
Cheap LED is where reputations get damaged, so the spec matters more than the technology. Four lines do the work:
- CRI 90+ for any living space, façade, or display work. Below ~80, finishes and skin tones look wrong, and the client just says “it looks cheap.”
- Color temperature and binning. 2200K–2700K gives the warm incandescent look; tight binning keeps every fixture in a run reading as one continuous color instead of a patchwork.
- Driver and dimmer compatibility. “Dimmable” on the box isn’t a guarantee — flicker, drop-out, and buzz are driver/dimmer mismatches. Confirm against the client’s control system before ordering the case.
- L70 and warranty. LEDs fade rather than fail, so spec a stated L70 (the point output drops 30%) and a real warranty — that’s what makes the rated life mean something.
LED vs incandescent by application
Permanent lighting. Fixtures mounted to stay reward a long maintenance life and consistent color far more than a cheaper bulb, because relamping a permanent run means ladders, lifts, or pulling trim.
Landscape and outdoor. Long dusk-to-dawn run hours, weather exposure, and heat punish incandescent fastest, where LED’s low heat output and vibration resistance decide it.
Holiday and Christmas lights. Durability is the buying factor — LED strings run cooler, resist breakage, draw a fraction of the power, and survive the storage-and-redeploy cycles that destroy incandescent. The DOE notes an LED string could still be running 40 seasons from now. Stock up on commercial-grade wholesale holiday lighting before the seasonal rush.
When incandescent still fits
Incandescent still turns up on legacy and replacement jobs, or with a client attached to the look — and the objections are all solvable at the spec level:
- “I like the warm glow.” → 2200K–2700K at CRI 90+ replicates it without the heat or the relamping.
- “I’ve had LEDs flicker.” → That’s a driver/dimmer mismatch or bottom-bin product, not a property of LED.
- “It costs more.” → One relamp cycle of labor on an embedded fixture usually erases the difference.
FAQs
What is the difference between LED and incandescent bulbs?
An incandescent bulb heats a filament until it glows, losing most of its energy as heat; an LED passes current through a semiconductor that emits light directly. As a result, LEDs use at least 75% less energy and last up to 25 times longer.
Are LED lights brighter than incandescent?
Not inherently. Brightness is measured in lumens, not watts — an LED just produces the same lumens at far lower wattage. A 9W LED and a 60W incandescent both put out about 800 lumens.
What CRI should I spec for residential and façade work?
CRI 90 or above for living spaces, façades, and color-critical areas. Below ~80, finishes and skin tones look off — the most common complaint on budget LED.
Why do some LED installs flicker or buzz?
Almost always a driver-to-dimmer mismatch, not a defect. Confirm the driver is compatible with the client’s dimmer or control system before ordering.
How do I match the warm look of incandescent with LED?
Spec 2200K–2700K color temperature at CRI 90+, with tight-binned product so fixtures in the same run read as one consistent color.
Are LED holiday lights worth it for install crews?
Yes — LED strings run cooler, resist breakage, draw far less power, and survive storage and redeployment, so replacement and labor costs drop season over season.
Thunder Lighting supplies installers, contractors, and distributors by the case across permanent, landscape, and holiday categories — spec’d, binned, and warrantied for professional installs.
