Ofjäähdytysneste

Ofjäähdytysneste, commonly known as antifreeze or coolant in English, is a vital fluid used in internal combustion engines to regulate temperature. Its primary function is to prevent the engine from overheating during operation and freezing in cold conditions. This dual capability is achieved through the addition of specific chemicals to a base fluid, typically water.

The most common base for ofjäähdytysneste is water, which has excellent heat transfer properties. However, pure water has a freezing point of 0°C (32°F) and a boiling point of 100°C (212°F) at atmospheric pressure. To overcome these limitations, ethylene glycol or propylene glycol is added. These glycols significantly lower the freezing point and raise the boiling point of the mixture. For example, a 50/50 mixture of water and ethylene glycol can protect against freezing down to -37°C (-34°F) and prevent boiling until around 108°C (226°F).

In addition to freeze and boil protection, ofjäähdytysneste contains additives to prevent corrosion and scale formation within the engine's cooling system. These inhibitors protect the various metal components, such as the radiator, engine block, and water pump, from damage. Different types of coolants exist, often categorized by their chemical composition (e.g., IAT, OAT, HOAT), which dictates their service life and compatibility with specific engine designs. Regular checks and replacement of ofjäähdytysneste are essential for maintaining engine health and preventing costly repairs.