Demineralized water (also known as kaodemi water) is water from which almost all dissolved minerals, ions and salts, such as calcium, magnesium, sodium and chlorides, which normally form scale, have been removed. The demineralization process is usually performed by passing the water through ion exchangers or reverse osmosis
Due to the absence of minerals that cause the formation of scale, demineralized water is ideal for use in various devices and processes:

- Refrigeration systems: Used to top up or fill engine cooling systems (often in combination with antifreeze) to prevent limescale from forming on metal surfaces.

- Accumulators: Essential for refilling lead batteries, because minerals from ordinary water can damage the battery cells.

- Household appliances: Recommended for use in steam irons, air humidifiers and inhalers, because it prevents the accumulation of scale and extends the life of the device.

- Industry and laboratories: It is used as a solvent, washing agent, raw material for the production of chemical products and everywhere where chemically clean water is needed.