An experimental and theoretical study was undertaken for three ether glycols (mixtures of isomers). The present paper, being the first part of a complex study, reports the experimental part of the study using a static apparatus, namely, the vapor-liquid equilibria of dipropylene glycol methyl ether (DPM), dipropylene glycol n-butyl ether (DPnB), and propylene glycol n-butyl ether (PnB), and the vapor-liquid equilibria of their pseudo-binary mixtures composed of (PnB + DPM), (DPM + DPnB), (PnB + DPnB), and the aqueous solutions of each ether. The explored temperature range is between 283.15 and 363.15 K. The experimental points were fitted using the Antoine equation. No literature data was found for comparison. The aim of this paper is not only to provide the obtained experimental data but also to highlight the eventual challenges when working with very low vapor pressure compounds and mixtures. The second part is related to a theoretical study with the development of a thermodynamic model for the representation of the experimental data.