Water curtain walls, also known as wet curtain walls, consist of water curtain panels and frames, commonly used in negative pressure ventilation and cooling systems. In negative pressure ventilation and cooling systems, negative pressure fans are used to extract polluted and hot air from indoors, while the water curtain wall opposite the fans is utilized for intake. Fresh, hot outdoor air is cooled and filtered as it passes through the wet holes of the water curtain wall, undergoing a heat exchange with the water.