sähköresistanssilämmitystä

Sähköresistanssilämmitys, known in English as electrical resistance heating, is a method of heat generation that occurs when an electrical current flows through a conductor with resistance. This resistance causes some of the electrical energy to be converted into thermal energy. The fundamental principle behind this phenomenon is Joule's law, which states that the heat produced is proportional to the square of the current, the resistance of the conductor, and the time for which the current flows.

The core component of most resistance heating systems is a heating element, typically made of a material with high electrical resistance and capable of withstanding high temperatures, such as nichrome (an alloy of nickel and chromium). When electricity passes through this element, its resistance impedes the flow of electrons, leading to collisions that generate heat. This heat can then be transferred to the surrounding environment through conduction, convection, or radiation.

Electrical resistance heating is a widely used technology due to its simplicity, reliability, and controllability. It finds applications in a vast array of devices, from domestic appliances like toasters, electric heaters, and ovens, to industrial processes such as metal melting, drying, and space heating in buildings. The efficiency of resistance heating is generally very high, as most of the electrical energy is converted directly into heat, although some energy may be lost due to heat escaping the intended area. The power output can be easily controlled by adjusting the voltage or current supplied to the heating element, or by altering the resistance itself through design.