How an incandescent bulb makes light
Incandescent means "to give off light from being heated," and that is exactly how the classic bulb works. Electricity runs through a thin filament, the filament heats until it glows, and you get warm, familiar light. It is beautifully simple, and beautifully inefficient: about 90% of the energy becomes heat, not light.
For over a century, the incandescent lit the world and paved the way for everything that came after. Today, U.S. efficiency standards have phased out the everyday general-service incandescent in favor of LED. But that is not the whole story. Specialty incandescent bulbs are still made and still needed, in ovens, appliances, heat lamps, and the countless odd sockets where nothing else quite fits. When you need one of those, GoodBulb stocks the hard-to-find ones.
The many shapes of incandescent
Here is a quick tour of the specialty incandescent world, and where each one shows up.
- Standard A-shape (A15, A19, A21): the classic teardrop, in lamps, fans, and everyday fixtures.
- Vintage / Edison-style: exposed decorative filaments for restaurants, bars, and homes that want character.
- C bulbs (C7, C9): Christmas strings, night lights, and signs.
- Chandelier / candelabra: flame-tip and torpedo shapes for chandeliers and sconces.
- Globe: round bulbs for vanities, bathrooms, and string lighting.
- Grow lights: for indoor gardens and seedlings that need more than a window.
- Heat lamps: infrared bulbs that keep bathrooms warm, keep food warm at the buffet, and warm a reptile's basking rock.
- Low and high voltage: 12V and 24V for campers and boats; 230V and 277V for warehouses, hotels, and hospitals.
- Appliance and microwave bulbs: the little ones you only think about when they burn out.
- Pool lights: to light the water and keep swimmers safe after dark.
- S-type (S6, S11, S14): indicator lights for panels, signs, and marquees.
- Shatter-resistant: coated bulbs that contain the glass if they break, for safety-sensitive spaces.
- Half-chrome / silver-bowl: a mirrored top that redirects light and cuts glare, common in restaurants.
- Flood and spot: for recessed cans and outdoor fixtures.
- Tubular: appliances, exit signs, and office fixtures.
- Colored bulbs: a rainbow of options, and part of our Buy Light, Give Light program, where colored-bulb sales fund good causes.
- Bug lights: yellow bulbs that shift to a wavelength insects are far less drawn to, so the bugs stay away from you.
The honest advice
For everyday lighting, LED is the answer: it uses about 90% less energy, lasts up to 25 times longer, and now comes in every color and shape people used to buy incandescent for. But for the specialty jobs a real incandescent still does best, you should be able to get exactly the right one, made or sourced honestly, and told plainly where it comes from. That is what we do.
(Curious why the "A" in A19 stands for "arbitrary"? We wrote a whole short post on that.)