Overview of Electrical Heating
Electric heating is the process by which electrical energy is turned into heat. This process occurs when an electric current passes through a resistor, a device that turns the current into energy.
Electric heating can also occur through a heat pump, which uses an electric motor to draw heat from a source and pump it into an area to be heated. There are a wide variety of devices that provide electric heat.
While the basic principles of these devices are the same, the manner in which they deliver heat is different. Radiative heaters (commonly referred to as space heaters) contain a coil that reaches a high temperature and emits heat.
Convection heaters produce warm air that is released into the surrounding area through vent holes. Some convection heaters use an electric fan to speed up the airflow.
Radiant heating systems use electricity to heat tubes of water, which are generally located under the floor of a building. These tubes of water heat the floor, which then heats the surrounding area.
Mechanics of Electrical Heating
When an electric current passes through a resistor, the moving particles that form the current interact with the resistor's atomic ions so that heat is produced. The resistor creates an electric field that accelerates the charged particles in the electric current, and these particles give up part of their kinetic energy each time they collide with the atomic ions.
The atomic ions absorb this kinetic energy, which manifests itself as heat and causes an increase in the temperature of the resistor. A typical electric heater has many resistors, which pass their heat to the heater's conductor (typically a series of metal coils).
In this manner, energy is transferred from an electric power supply to the resistor and ultimately to the conductor, which then disperses the energy into the surrounding environment.
Environmental and Economic Considerations
Electric heating is considered environmentally-friendly and economically-efficient because of the high conversion rate of electric particles to heat. Modern electric heating systems have an ability to convert nearly all of purchased electricity into heat.
Many newer electric heating systems have storage capabilities that allow these systems to purchase electricity when the price is low, such as overnight, and store that electric energy until it is needed to produce heat. You can calculate the cost of an electric heating system by estimating the system's cost per kilowatt hour, multiplying this number by the heater's efficiency, and then multiplying this quantity by the number of kilowatt hours the system will be used.