Different electric water heaters use different heating element, and the insulating materials used are different. In the market, electric water heaters generally use two types of tubular heater:
One is a non-metallic Stainless steel immersion heater, such as a glass Stainless steel immersion heater, a ceramic heating tube, etc., such as glass or ceramic itself is a poor conductor of electricity. They all put electricity on the outside of the heating element, and the water is inside the heating element. In this way, the material of the heating element itself is insulated. Ceramic heating tube, water and electricity are completely isolated. This kind of heating tube is anti-dry!
The second type is a metal Stainless steel immersion heater, such as a Industrial immersion heater, a copper heating tube, and the like. Such a heating tube is composed of a heating wire, an outer stainless steel tube and magnesium oxide for insulation. Magnesium oxide is filled between the heating wire and the stainless steel tube, and the magnesium oxide is only thermally conductive and non-conductive. This also achieves the purpose of insulation.
Throughout the heating body of the market water heater, the copper heating element and the stainless steel heating element are the mainstay of the heating body. This type of heating element has high heat generation efficiency and mature technology. For example, the European Union uses a stainless steel tubular heating element.