Haihduttamisjäähdytystä

Haihduttamisjäähdytystä, known in English as evaporative cooling, is a physical process that cools air through the evaporation of water. It is a method of heat rejection used in various applications, from industrial processes to residential air conditioning. The principle behind evaporative cooling is that when water evaporates, it absorbs heat from its surroundings, thus lowering the temperature of the air. This phenomenon is commonly observed when one perspires; the evaporation of sweat from the skin cools the body.

In practical applications, such as air conditioning units, warm, dry air is passed over a wetted medium, like a pad or a porous material. As water evaporates from this medium, it absorbs heat from the air, causing the air's temperature to drop. The now cooler, more humid air can then be circulated into a space. The effectiveness of evaporative cooling depends on the ambient humidity. It works best in dry climates where the potential for evaporation is high. In humid conditions, less water can evaporate, making the process less efficient.

Evaporative cooling systems are generally considered more energy-efficient than traditional refrigeration-based air conditioning systems because they do not rely on compressors and refrigerants. They also add moisture to the air, which can be beneficial in dry climates. However, their cooling capacity is limited by the wet-bulb temperature of the air, and they are not suitable for applications requiring very low temperatures or in environments where high humidity is undesirable. Examples of evaporative cooling include swamp coolers, cooling towers, and even natural processes like a breeze blowing over a body of water.