Open cooling towers are devices used to remove heat from water by exposing it to air. They work by allowing warm water to flow over fill material, which increases the surface area for heat exchange. As the water trickles down, some of it evaporates, taking heat away and cooling the remaining water, which is then recirculated back into systems like HVAC or industrial processes. These towers are commonly found in large facilities, such as power plants and manufacturing plants, where efficient cooling is essential. Open cooling towers are typically more cost-effective than closed systems but require regular maintenance to prevent issues like algae growth and scale buildup.