How does a room heater work?

Every electric heater turns 100% of its electricity into heat, yet a halogen warms your face in a second while an oil radiator needs many minutes to get going. Radiant heaters (rod, quartz, halogen, carbon) make something glow, and their infrared warms whatever it shines on, in seconds.

Read how it works: How does a room heater work? · The history of the room heater · More boxes on Glassbox

Chapters in this interactive model

1. A family of heaters: Nine ways to warm a winter room: glowing tubes, hot oil, blowing air and a pot of charcoal.
2. Glow, flow and touch: Radiation warms you. Convection warms the air. Conduction lets it leak out through the walls.
3. Inside an oil radiator and a PTC heater: Oil that stores heat, a strip of two metals that switches it, and a stone that can’t overheat.
4. Heat a room on a Delhi winter night: How long it takes, how warm it gets, and what the night costs.
5. Dry air and the silent gas: Why heated rooms feel dry, and why a fire in a closed room can kill while you sleep.
6. Use a heater safely: Distance from fabric, the right socket, fresh air, and a heater that switches itself off.