Heat Moves Three Ways, and Heaters Use All of Them
A heater warms a space. Understanding how heat travels explains why some heaters feel warmer than the thermometer says.
A heater is a device producing warmth. Heat moves by three mechanisms and heaters exploit different ones: conduction through direct contact, convection through moving air, and radiation through infrared waves. A radiant heater warms you directly even in cold air, which is why a patio heater works outdoors where a fan heater would not.
- A warming device. *An electric heater.*
- Heat — thermal energy. *Turn up the heat.*
- Heater in baseball slang — a fast pitch. *He threw a heater.*
Word forms
| Form | Word | Example |
|---|---|---|
| Noun | heater | A fan heater. |
| Plural | heaters | Two heaters. |
| Verb | heat | Heat the room. |
| Noun | heating | Central heating. |
| Related | radiator | A hot radiator. |
How it is used in a sentence
- A radiator mostly heats by convection.Despite the name.
- Radiant heaters warm objects, not air.Which is why they work outdoors.
- Heat pumps move heat rather than making it.Which is why they can exceed 100 per cent efficiency.
How heat travels
- Conduction — through direct contact between materials
- Convection — carried by moving fluid or air
- Radiation — infrared waves, needing no medium
- Radiators — despite the name, mostly convect
- Heat pump — moves existing heat instead of generating it
From *heat*, Old English *hætu*, from *hat*, hot. The agent suffix *-er* forms the device name.
Why is a radiator called that if it convects?
Early cast-iron models did radiate a significant share of their heat. Modern panel radiators move most of it by convection, but the name stuck.
How can a heat pump be more than 100 per cent efficient?
It does not create heat; it moves heat from outside to inside. The output can exceed the electrical input several times over.