Oil heater

An oil heater, also known as an oil-filled heater, oil-filled radiator, or column heater, is a common form of convection heater used in domestic heating. Although filled with oil, it is electrically heated and does not involve burning any oil fuel; the oil is used as a heat reservoir (buffer), not as a fuel.

How it works

Oil heaters consist of metal columns with cavities, inside which silicone oil(mostly siloxanes like polydimethylsiloxane) flows freely around the heater. A heating element at the base of the heater heats up the oil, which then flows around the cavities of the heater by convection. The oil acts as a heat reservoir, with a relatively high specific heat capacity (approximately 2 kJ.kg⁻¹.K⁻¹) and high boiling point (approximately 150–300 degrees Celsius). The high specific heat capacity allows the oil to store a large amount of thermal energy in a small volume, while the high boiling point allows it to remain in the liquid phase for the purpose of heating, so that the heater does not have to be a high pressure vessel.