Excess molar enthalpies, measured at the temperature 298.15 K and atmospheric pressure conditions by means of a flow microcalorimeter, are reported for the ternary mixtures {x(1)(dibutyl ether or dipropyl ether) + x(2) 2,2-dimethylbutane (1 - x(1) - x(2)) 2,3-dimethylbutane}. A smooth representation of the results is described and the constant-enthalpy contours for each ternary system are displayed on the respective Roozeboom diagrams. The results serve to show that good estimates of the excess molar enthalpies of the ternary systems can be obtained from the Liebermann-Fried model by using the physical properties of the constituent pure components and the parameters determined from the binary mixtures of these components. (C) 2011 Elsevier Ltd. All rights reserved.