How do space heaters work?
Space heaters generally work by sucking in cold air, passing it over a heating element, and then expelling it via vents. The heating element is basically a block or coil (shapes that conduct heat well) of heat conducive material, such as porcelain or metal. These heating elements are provided heat via a resistor, in essence a circuit is made with a resistor placed in it, this resistor resists the flow of electricity, gaining heat as it does so, and transfers this heat to the heating elements, which then heat the cold air that has been sucked in, and the now hot air is expelled into the room. This electric circuit heating method is mostly used in portable space heaters, which are the most common kind. Permanently installed space heaters generally generate heat by burning various fuels, such as natural gas or propane. Such space heaters generally contain “flues”, i.e. ducts that expel waste gases created by the burning of fuel by the space heater. It is extremely dangerous to use such fuels in a portable heater, as such heaters usually cannot contain permanent flues in their basic design.
A now obsolete, and so often unconsidered, example of a space heater is a fireplace. A fireplace provides heat to a specific area and cannot be used as a central heating system. In this case, the fuel would be wood and the flue wood be the chimney.
How the hot air is expelled, as well as what heating element is used, depends on the type of space heater in question. Most space heaters radiate the heat through vents, a method that usually successfully heats the isolated are the space heater is being used to heat. This is usually why space heaters cannot successfully heat large rooms, as their radiated heat often dissipates before reaching the opposite end of the room.
For information about a heater thermostat check out this smart thermostat comparison.