kühlen

The German verb kühlen means to lower the temperature of something or to refrigerate. It describes the act of making something cooler, either to preserve its quality, ensure safety, or increase comfort. The related noun Kühlung denotes the cooling process, while Kühlgerät and Kühlkette refer to cooling devices and the cold chain. The verb is regular: ich kühle, du kühlst, er/sie kühlt, wir kühlen, ihr kühlt, sie kühlen; past participle gekühlt.

In physics and engineering, kühlen refers to heat transfer from a warmer body to its cooler surroundings. This occurs mainly by conduction, convection, and radiation, and may involve phase changes such as freezing or condensation that absorb latent heat. In technical contexts, cooling often uses energy input to move heat from a low-temperature reservoir to a higher-temperature one, as in vapor-compression or absorption refrigeration cycles.

Practical applications are widespread. In households, kühlen covers refrigerating food and beverages (Kühlschrank, Gefrierschrank) and maintaining beverages at a desired temperature. In industry, Kühlung removes heat from engines, turbines, and electronic equipment, using heat exchangers, cooling towers, and refrigeration systems. The term also appears in medicine and sports, where surface cooling or systemic cooling is used for safety or treatment. Overall, kühlen is a core concept across daily life, food safety, and industrial temperature control.