Thermal effectiveness was performed as preliminary research in shell and coiled tube heat exchanger with addition of Al 2 O 3 nanoparticles. In the present study, the effect of small concentration of Al 2 O 3 nanoparticles analysis for steady state. Water is selected as the working fluid of cold fluid and refrigerant R-22 as hot fluid. The present work also includes the effect of nanoparticles on logarithmic temperature difference (LMTD), amount of heat absorbed by the water as a time series function. Based on the result, the effectiveness of water-Al 2 O 3 nanoparticles as cold fluid shows good agreement on heat transfer parameter enhancement. The heat exchanger effectiveness increase until 2.2% compare to that of heat exchanger without Al 2 O 3 nanoparticles. This phenomenon indicates an increases of heat transfer process inside heat exchanger. The application of water-Al 2 O 3 nanoparticles on shell and coiled tube heat exchanger enhanced the convective heat transfer passively.