Electric Heating: Advantages and Applications

What is Electric Heating?

The process in which electrical energy is converted into heat by resisting the free flow of electric current is known as electric heating.

Whenever an electric current is made to pass through any circuit having a resistance of R ohms, then power dissipated in the circuit is equal to $\mathit{I^{\mathrm{2}}R}$ Watts. If the current flows for seconds, then the electric energy consumed in the circuit is equal to $\mathit{I^{\mathrm{2}}Rt}$ Joules. This energy is converted into heat and worked out as $\mathit{I^{\mathrm{2}}Rt}/4.2$ Calories, where 4.2 is a constant called mechanical equivalent of heat.

The use of heat produced by electricity is always economical proposition on the account of the present low cost and availability of electrical energy.

Advantages of Electric Heating

The chief advantages of electric heating over the other methods of heating such as oil, coal or gas heating are given as follows −

  • No Pollution

    The electric heating provides neat and clean atmosphere. As there is no coal dust or smoke and operators hand do not go black while operating an electric heating device. Also, the absence of flue gases does not result in pollution of atmosphere and there are no heat losses involved as that through smoke or flue gases. In electric heating, no irritating noise is produced and also radiating losses are very low.

  • Uniform Heating

    In case of electric induction heating, the heat can be produced within the work piece resulting in uniform heating of the job.

  • Easy Control

    The electric heating can be started instantaneously or stopped at a required time keeping a time gap between switching off and cooling of the heating circuit. With the electric heating, automatic switching controls are also possible.

  • Controlled Temperature

    In case of electric heating, the temperature can be controlled very precisely, say within ±5°C, which is not possible with non-electrical heating process.
  • Automatic Protection

    The electric heating is quite safe and respond quickly. It is because, the electric heating provides protection against over current and overheating by using fast control devices.

  • More Economical

    The electrical furnaces do not require big space for installation, no storage of coal and fire wood, no chimney to be constructed, no extra-heat insulation is required. All these factors make the electric heating more economical as compared to the non-electric heating.

    Also, the electrical heating appliance is cheaper and they do not require much skilled persons for their operating and maintenance.

  • Highest Efficiency of Utilisation

    The heat produced by electric heating does not go waste through chimney and other by-products whereas most of the heat produced is utilised, up to 75% to 100%, by the material being heated electrically.

  • Heating of Bad Conductors of Heat and Electricity

    The electric heating can be used for heating the poor conductors of heat and electricity such as wood, plastic and bakery items, etc.

Application of Electric Heating

The electrical heating is widely used in various heating processes in domestic, commercial and industrial applications, some of them are listed as follows −

Domestic & Commercial Applications

  • Electric heaters, such as room heaters, immersion heaters for water heating, hot plates for cooking, etc.

  • Electric irons

  • Electric kettles and coffee percolators

  • Popcorn plants

  • Hot air driers for drying wet hairs or laboratory equipment

  • Electric ovens / electric tandoors / electric toasters

Industrial Applications

  • Melting for extraction or purification of metals.

  • Heat treatment for various processes such as hardening, normalising, annealing, tempering, soldering, brazing, joining, case hardening, etc.

  • Enamelling of copper conductor.

  • Heat treatment of painted surfaces.

  • Making of plywood.

  • Making of biscuits, breads, etc.

  • Baking of potteries or insulators or sanitary fittings.

  • Moulding of glass for making glass appliances, etc.

Updated on: 23-Feb-2022

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