The International Institute of Refrigeration has established a series of Commission B1 (Thermodynamics and Transfer Processes) Conferences, held every 4 years, to discuss refrigerants thermophysical properties and transfer processes. This conference follows the 2001 Conference in Paderborn, Germany, the 2005 Conference in Vicenza, Italy and the 2009 Conference in Bolder, USA. Welcome to the next conference on Thermophysical Properties and Transfer Processes of Refrigerants, TPTPR2013 Delft, the Netherlands, June, 17th -19th, 2013. Themes: Heat and Mass Transfer Phenomena in Refrigeration Systems & Natural and low GWP refrigerants.