This report is about the design of heat recovery system in a sheet rock plant. A sheet rock is basically a gypsum board which is mainly used as a finish for walls, ceilings in households and commercial buildings. According to the given problem, during summer months the city water supplies to the manufacturing plant at a higher temperature of 900 F but during other months the temperature of water supply as 450 F. The de mand of water temperature is 85o F for the process so the city water is heated by natural gas burners when it’s in a storage tank. During the final stage of sheet rock production, heated air is used in a closed oven with sheet rock for the drying process. The air gets exhausted from aluminum stacks. This waste heat energy is being recovered it in the form of energy with the help of specially selected heat exchanger. The energy recovered will be minimising the need of natural gas burner which is to heat the city water receiving at a temperature of 450 F. This would reduce the need of natural gas to use as the main source of heating the city water for production of sheet rock. The heat recovery system would be compatible to work for 24 hr in a 6 days week frame till 8 months. The report will include the type of heat exchanger selected, pump for heat recovery and piping system with fittings and be routing for heat recovery. This would also include the cost involved in the whole additional process as installation, operational and maintenance cost with a calculated payback period of time for investment.