In this work we report the excess molar enthalpies at 298.15 K and atmospheric pressure of the mixtures 2,2,2-trifluoroethanol (TFE) + poly(ethylene glycol) dimethyl ether 250 (PEGDME 250), methanol + tetraethylene glycol dimethyl ether (TEGDME) and methanol + PEGDME 250. In the case of mixtures with methanol, the UNIFAC and DISQUAC group contribution models have been used to compare the predicted and experimental results. We have used three versions of the UNIFAC model due to Tassios et al., Larsen et al. and Gmehling et al., for which three group assignments were made. The best predictions were found with the Gmehling version of the UNIFAC model.