Experimental excess molar enthalpies of the ternary systems (dibutyl ether (DBE) + 1-butanol + heptane) and the corresponding binary systems at T = 298.15 K and T = 313.15 K at atmospheric pressure are reported. A quasi-isothermal flow calorimeter has been used to make the measurements. All the binary and the ternary systems show endothermic character. The experimental data for the binary and ternary systems have been fitted using the Redlich-Kister equation, the NRTL and UNIQUAC models. The values of the standard deviation indicate good agreement between the experimental results and those calculated from the equations. C 2009 Elsevier Ltd. All rights reserved.