“…Before introducing nano fluid to improve performance of the thermal devices, it is necessary to analyse the geometrical parameters. In geometrical domain some investigation has been done to perform thermal or heat transfer analysis on various exchangers elements and parameters like analysis on diverse absorber plate shape 2,3,4,5) , specifically HVAC duct 6) , Ventilators 7) , flat surfaces 8) and tubes of different shape and size in solar air heater and collectors 2,3,4,5) , effect of perforation, shape and size of tapered hollow conical rings 9) , analysis the effect of helical coil, plain tubes, bundle of tubes with or without roughness in shell-tube type heat exchanger 10,11,12,13) , micro-channel 14,15,16,17) , mini channels 18,19) , analysis of number/location of fins in LED 20) with diverse fluids like air, water and nano fluid, 20,21,22) , nano-lubricant, bio-lubricants, bio-oils 61) , green bio-glycol nano fluid 23,24,25,26,60) , nano-fluidic or refrigerant 27,28) . Some researchers performed work on thermal storage with diverse material characterized as sensible materials under packed bed related to thermal storage like clay, dry clay, nylon 6 etc.…”