Reliable azeotropic data have been measured for the following four binary systems: methanol + diethoxymethane, 2-propanol + diethoxymethane, diethoxymethane + dimethyl carbonate and 2,2-dimethoxybutane + toluene by means of a wire band column. Additionally, solid-liquid equilibria (SLE) for the six binary systems of benzene and cyclohexane with diethoxymethane, 2,2-dimethoxybutane, and 1,1-diethoxyethane have been measured by a visual technique. Due to correlation requirements of the SLE experimental data, the heat of fusion for 2,2-dimethoxybutane and 1,1-diethoxyethane have been measured using a Tian-Calvet batch calorimeter. The azeotropic data were compared with literature values, when available, or with predicted data by Modified UNIFAC (Dortmund) when all required parameters were at disposal, too. For the description of the SLE data the NRTL model has been used with good results. Also, the results of the Modified UNIFAC (Dortmund) model have been checked using the already available "ether" group parameters. The work was carried out in order to supplement the available data base for acetal systems required for the introduction of a new "acetal" group in the Modified UNIFAC (Dortmund) model.