In plumbing systems and heat exchangers, of the important criteria for selecting common fluids such as ethylene glycol and water is to create a very low pressure loss, which as a result of this intrinsic feature, accurate flow measurement is possible. In present study, the numerical study of pressure loss and Nano fluid flow rate with base fluid has been investigated to measure other parameters. In present study, the flow of Al2O3 and TiO2 Nano fluids in residential building plumbing systems were studied in laboratory under calm and turbulent flow conditions with different boundary conditions, different concentrations of Nano fluid. The results show that the use of nanoparticles, especially metal nanoparticles in base fluids, leads to an increase in pressure loss, which is caused by the vortex currents created at the end of the pipe path, especially the parts where the sudden change in pipe cross section and also the bends.