摘要 |
A pressureless electric water heater for domestic use having a cylindrical double-walled tank for holding a quantity of a heat transfer liquid such as water. Cold water enters a copper coil immersed in the heat transfer liquid. The heat transfer liquid is heated by an electric heating element that extends down a double-walled top. The inner walls and the outer walls of the tank and the upper and lower walls of the top may be spaced apart using any convenient spacing distance, in order to accommodate an amount of thermal insulation, such as fiberglass, foam, cellulose or cardboard, preferably includes open air spaces between the linings of insulation or between a lining of insulation and a wall or surface.
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