Engr. Dr. Muhammad Nawaz Iqbal
Electric heating techniques have a number of advantages over other types of heating, including the ability to precisely control temperature and heat energy distribution, the absence of combustion as a source of heat, and the ability to reach temperatures that are difficult to reach with chemical combustion. With a high concentration of power per unit area or volume, electric heat can be precisely administered where it is needed in a process. Anywhere in a facility is a potential location for an electric heating device, which can be constructed in any desired size. Electric heating systems often produce little heat as a byproduct and are quiet and clean. Electrical heating equipment responds quickly, making it ideal for fast-cycling mass manufacturing machinery.
Electric heating uses relatively inexpensive tools to directly convert electrical energy into heat energy with a conversion efficiency of roughly 100%. Applications that are frequently used include industrial processes, cooking, water heating, and space heating. An electrical appliance that transforms an electric current into heat is called an electric heater. Every electric heater contains a heating element that is an electrical resistor and operates on the principle of Joule heating. When an electric current flows through a resistor, the electrical energy is transformed into heat energy. The active element in most contemporary electric heaters is nichrome wire; the heating element shown on the right is nichrome wire supported by ceramic insulators.
In a convection heater, the heating element uses thermal conduction to warm the air that comes into contact with it. Since hot air is buoyant and less dense than cool air, it rises as a result, making room for additional cool air to enter in its place. This creates a hot air convection current that rises from the heater, warms the area around it, cools, and then repeats the process. Thermo fluid or oil may occasionally be used to fill these heaters. They are perfect for heating a room that is enclosed. Compared to radiant electric heaters, they run quietly and pose a smaller risk of igniting a fire if they accidentally come into contact with furniture.
Heating wires are buried in the floor of a structure with an electric under floor heating system. A conductive heating substance conducts current that is either directly provided by the line voltage (120 or 240 volts) or at low voltage through a transformer. Direct conduction heats the flooring by the heated cables, which turn off when the temperature specified by the floor thermostat is reached. A hotter floor surface transfers heat to cooler adjacent surfaces (ceiling, walls, furniture), which absorb the heat and reflect it back to still cooler surfaces. When equilibrium is reached everywhere, the cycle of radiation, absorption, and reflection stops. It begins slowly, slows down as set point temperatures are approached.
The fundamentals of heating are constant. Old-fashioned electric and warm water (hydronic) under floor heating systems built into the floor structure are both slow and unable to adapt to internal demand or lifestyle demands. The most recent variation inserts specialized electric heating systems, blankets, and additional insulation immediately underneath floor décor and on top of construction floors. Floors in construction remain chilly. It can adjust in a matter of minutes to changing weather conditions as well as internal demand demands, such as lifestyle factors like being indoors or outside, at work, resting or sleeping, having more people around or cooking, etc.
Any system’s effectiveness is dependent on how its limits are established. Electric room heating is 100% efficient for a client of electrical energy because all purchased energy is transformed into heat. However, the overall efficiency is significantly reduced when a power plant that generates energy is added. For instance, for every 10 units of fuel energy discharged by a fossil fuel power plant, only 3–5 units of electrical energy are produced. Despite the electric heater’s 100% efficiency, more fuel is required to generate the same quantity of heat than if the fuel were used in a furnace or boiler within the building. Burning the fuel at the end user’s building would be more effective overall if the same fuel could be utilized for space heating by a consumer. On the other hand, switching from electric heating to heaters that burn fossil fuels isn’t always a smart idea because it eliminates the option for sustainable electric heating, which is possible by obtaining the power from a renewable source.
An electrically powered heat pump can increase the temperature within a building more effectively by drawing energy from the ground, the outside air, or waste streams like exhaust air. When compared to resistive heating, this can reduce the amount of electricity required by as much as 35%. Transferring electricity via the grid is practical when hydroelectric, nuclear, or wind power is the dominant source of energy because these sources may be too far away for direct heating applications (with the notable exception of solar thermal energy).