Abstract Various industrial equipment is utilizing water as a cooling agent for maintaining their operating temperatures within the stipulated range. The water-cooled equipment produces a large quantity of hot wastewater, which is generally sent to the chiller units for cooling. Proposed reduced scale model of a long single basin, single slope still is an attempted to utilize this waste energy for desalination. Experimental and theoretical evaluation has been carried out by feeding hot water at 70 ± 1℃ at a constant flow rate of 1100 l/h. Dunkle, Kumar & Tiwari and Tsilingiris models have been used for the comparative theoretical analysis of long hot waste water still. The maximum and minimum values of partial pressure have been recorded at the water and glass surfaces are 32492.648 & 10658.271 N/m2 and 19906.001 & 5660.855 N/m2 respectively. At 0.1, 0.3, 0.5, and 1.2 m the partial pressure at the water surface is 63.23, 81.39, 71.77 and 88% higher than the glass surface. Kumar & Tiwari leads Dunkle and Tsilingiris models at 0.1 m by 6.91 and 4.63%, whereas this difference grows to a maximum value of 42.093 and 55.07% at 1.1 m respectively.