Hybrid cooling towers also known as cooling tower without visible plume. hybrid cooling tower is a wet cooling tower in which the process fluid is pre‐cooled by air comes out of evaporative cooling in finned coils. In hybrid cooling towers the plume is mixed with a dry, hot air stream prior to leaving the cooling tower. This air stream is generated in heat exchangers, the water to be cooled serve as the heating medium. No additional energy is therefore required to heat the air.