There is no way to eradicate a more accurate answer, the degree of house insulation, the use of the environment has a lot to do with. Coal-fired heating is really cheap, but you have to transport coal, slag. Electric heating is a trend, the cost of central air conditioning is 200 / flat. Suggestions to understand the electromagnetic air heating unit, is a use of electromagnetic induction principle, the conversion of electrical energy into magnetic heaters, in the controller by the rectifier circuit will be 50/60HZ AC voltage into DC voltage, and then through the control circuit will be converted to DC voltage frequency of 20-25KHZ high-frequency voltage, high-speed changes in the current through the coil will produce a high speed magnetic field, when the magnetic field, the magnetic field will be converted to high-frequency voltage. High-speed magnetic field, when the magnetic field inside the magnetic lines of force through the metal conductor to produce countless small eddy currents, so that the conductor itself high-speed heating, and then the conductor of the body of the heat into the heating space to achieve the purpose of rapid heating. Electromagnetic heating furnace and resistance heating furnace comparison Electromagnetic heating furnace: 1, electromagnetic induction heating, the real sense of separation of water and electricity, circuit and water insulation. 2, low-voltage soft start, reduce the harm of current surge impact, to avoid damage to equipment due to voltage fluctuations, safety is guaranteed. 3, frequency conversion power output part of the voltage fluctuations according to changes in the size of the automatic regulation of the current to ensure constant power, will not be due to the voltage increases the current rises with it, resulting in damage caused by insufficient electrical load. Resistance heating furnace: 1, resistance heating, regardless of the resistance material within or outside, are through the thermal conductive medium conduction, not the true sense of water and electricity separation, there is a medium due to corrosion or breakdown caused by leakage of hidden trouble. 2, the relay directly to the resistance bar power supply, the impact current is large, easy to overcurrent shock and cause voltage fluctuations, other electrical appliances are also damaged. Structural design electromagnetic heating furnace: the entire structure of the water circuit, circuit separation, reasonable structure, high security Resistance heating furnace: the entire water and electricity are not separated, security risks Energy saving electromagnetic heating furnace: high-frequency electromagnetic induction heating, electromagnetic induction through the direct action of the water gallon, so that the water gallon itself heated to reduce the process of conduction through the medium, heat loss is less, high thermal efficiency, that is, the addition of that is hot, without the need to store heat containers, the thermal efficiency of the instant can be as high as 98% or more than than the medium, the heat loss is less, the thermal efficiency is high. Can be as high as 98% or more, more than 30% energy saving than resistance. Resistance heating furnace: 1, resistance heating, through the thermal conductive medium to conduct heat to the water gallbladder, heat loss 2, localized heat, easy to produce scale, affecting heat transfer 3, some materials attenuation is serious, resulting in thermal inefficiency Use of life Electromagnetic heating furnace: industrial-grade electromagnetic, high-temperature-resistant wire, the use of more than 15 years Resistance heating furnace: resistance wire is easy to deteriorate, the life of a short period of time, generally 3 to 5 years Mute electromagnetic heating furnace: Heating power frequency 20000Hz, beyond the normal human hearing frequency, not only to improve the thermal efficiency, but also silent and environmentally friendly. Resistance heating furnace: industrial frequency power supply work with "buzzing" industrial frequency noise, resistance to water heating, surface water temperature is high, there are bubbles produce the sound of boiling water. Maintenance electromagnetic heating furnace: electromagnetic induction heating, work, heating the core component is a fixed magnetic field, water through the magnetized, magnetized water department structure, maintenance-free system. Resistance heating furnace: resistance wire is generally replaced once every 3 to 5 years, and because it produces scale, to be descaled regularly. The above content is for reference only, if there is a problem, please communicate and correct.