Efficiency of Induction Heating

A Comparison of Efficiency and Power Consumption for Induction Heating versus other Heating Methods

UltraFlex Power Technologies often has customers who ask about the potential power savings for using Induction over other common heating methods. The following provides a guide for potential power savings that customers may see.
Heating by Induction has minimal wasted heat, with direct transfer of energy to the part being heated. This high efficiency results in significant power savings. Induction heating proves to be a highly efficient method for industrial heating applications. 


1.) A 1998 study conducted by Lawrence Berkeley National Laboratory for the Department or Energy, found induction cooktops to transfer 84% of the power to the load vs. only 71% for electric coils and 40% for gas.

Type of Heating Element Efficiency Factor
Electric – Induction 84.00%
Electric – Radiant* 71.00%
Gas 40.00%

Efficiency Chart Source: US Department of Energy (1998)

*Electric radiant efficiency varies depending on size of heating element relative to part size. If the element is larger than the part to get sufficient power, the efficiency will be much less.


2.) UltraFlex’s testing and research is comparable to these results. Below is our more conservative estimate of the efficiency of power delivered to the desired load vs. heat transferred to other parts and environment for a variety of heating methods.

Examples Stated Power vs. Delivered Power
Type Input Power (kW) Efficiency Delivered Power (kW)
Induction* 2.8 90% 2.52
Electric – Radiant 2.0 55% 1.1
Gas 3.5 50% 1.75

* Into a magnetic steel load below curie.


3.) If we “normalize” the above data, to show delivered power of 1.0 kW for all methods, we see the difference in required input power. We can then easily calculate the power savings of other Induction vs Electric and Gas.

Required Input Power for 1.0 kW Delivered Power and Associated Power Savings
Type Input
Power (kW)
Efficiency Delivered Power
(kW)
Power Savings of Induction vs Alt
Induction 1.11 90% 1.0
Electric – Radiant 1.82 55% 1.0 39%
Gas 2.00 50% 1.0 44%

4.) For batch heating processes, the efficiency can be even greater since you only spend energy with Induction Heating when you need to heat. There is no wasted energy with Induction Heating versus keeping furnaces and ovens running or delays in pre-heating ovens.


References:
Berkeley, Lawrence. “Technical support document for residential cooking products, volume 2: Potential impact of alternative efficiency, Levels for residential cooking products.” n.d.

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