This paper reports an experimental investigation of condensation heat transfer and pressure drop of an ozone friendly refrigerant, R-134a, inside a helical tube for climatic conditioning of hot regions. This study concerns the condensation of R-134a flowing through annular helical tubes with different operating refrigerant saturated temperatures. The average pressure drop is measured and compared with data from relevant literature. The measurements of R-134a were performed on mass flow flux ranges from 50 to 680 kg/m(2) s. The study provides experimental data that could be used for the design and development of more efficient condensers for refrigeration and air conditioning (A/C) systems working with the same refrigerant. (C) 2007 Elsevier Ltd. All rialits reserved.