Thermal Performance of ‘Still-on-Roof’ System with Water Flowing through the Roof

In the present communication, authors propose and analyze a system which consists of a solar still kept over the roof of a room, and a water-flowing arrangement in the roof. The performance of the system is studied under two modes of heat extraction, viz., constant flow rate, and constant collection temperature, An analytical model has been developed which provides explicit expressions for various performance parameters of the system. The model is useful in evaluating the system performance under the variation of different parameters. In order to appreciate the proposed configuration, numerical calculations are carried out corresponding to the typical climate of Delhi, India. The calculations show that the system is effective in reducing the heat flux entering the room and provides warm water in addition to the distilled water.