How do air cooler evaporative cooling pads work?

Air cooler evaporative cooling pads work based on the evaporative cooling effect, which is the physical process of water absorbing heat when it changes from liquid to gas. When water evaporates, it absorbs approximately 2,260 kJ of heat per kilogram of water, significantly reducing the temperature of the surrounding air. This process is particularly effective in dry air, because low humidity environments accelerate the evaporation of water, making the cooling effect more obvious. In contrast, in high humidity areas, the cooling effect is reduced due to the low evaporation rate due to the high water content in the air.

Air cooler evaporative cooling pads are usually made of highly absorbent honeycomb materials (such as plant fibers, specialty papers or synthetic resins) with a large surface area. A water pump delivers water to the top of the cooling pad, making it evenly wet and forming a water film. When the hot outside air passes through the wet cooling pad under the action of the fan, the water on the surface of the water film evaporates, absorbing heat from the air and causing the air temperature to drop. The cooled air is slightly more humid, but the temperature is significantly lower, and then it is sent to the target area. The water that is not evaporated will flow back to the bottom water tank, and will be recycled after being filtered, reducing water waste.

The cooling efficiency of the evaporative cooling pad is affected by multiple factors. The cooling effect is best in dry climates, while the effect is limited in high humidity environments. Materials with strong water absorption (such as high-quality plant fibers) can improve evaporation efficiency, while thicker cooling pads can extend the air contact time and enhance the cooling effect, but they will also increase wind resistance. Too high wind speed will reduce evaporation time and reduce cooling efficiency; too low wind speed will affect the ventilation volume, and the appropriate fan power needs to be matched. Hard water can easily form scale on the surface of the cooling pad, block the pores, and reduce efficiency. Therefore, it is recommended to use softened water or clean it regularly.

There are significant differences between evaporative cooling pads and traditional air conditioners in terms of cooling methods, energy consumption, and applicable environments. Evaporative cooling relies on water evaporation to absorb heat, which is a natural physical process, while traditional air conditioners rely on refrigerant compression cycles and consume more electricity. Evaporative cooling only requires water pumps and fans to operate, saving more than 80% energy than traditional air conditioners, and the operating cost is extremely low. Evaporative cooling increases air humidity and is suitable for dry areas, while conventional air conditioning reduces humidity and may cause dry air. Evaporative cooling works best in dry, well-ventilated environments, while conventional air conditioning is suitable for confined spaces and is not subject to humidity restrictions.