In the present study, heat transfer and friction characteristics of heat transfer exchanger with a new type of enhanced fin - convex fin was experimentally investigated. For comparison, a plain-fin heat transfer surface with the same dimension was also tested. At low Reynolds number the airside convective heat transfer coefficient of the convex-fin is 25% higher than that of the plain-fin. At high Reynolds number the heat transfer coefficients of the convex-fin is slightly higher than the heat transfer coefficient of the plain fin. The pressure drop of the new enhanced fin increases by 16%. The convex-fin is suitable for enhancing heat transfer at low and middle velocity condition commonly encountered in air-cooling industry. (C) 2017 Elsevier Ltd. All rights reserved.