This dataset represents experimental condensate mass flux values, obtainaned during experimental measurements of condensation of water vapor from humid air inside vertical channels formed by flat plates.Tables 1-3 show experimental condensation mass flux values, obtained at different operating conditions: temperature of humid air bulk flow, temperature difference between humid air bulk flow and main walls, and volume flow of humid air for three heights of vertical flat plates: 74 mm, 50 mm and 30 mm.Table 4 shows a dataset of 9 temperature measurements of the test section’s side wall on 16 locations with the height of vertical plates 50 mm.For more information about the experimental setup and the entire study related to condensation of water vapor from humid air inside vertical channels formed by flat plates, the readers are encouraged to check the published scientific article with the following DOI: https://doi.org/10.1016/j.isci.2021.103565THIS DATASET IS ARCHIVED AT DANS/EASY, BUT NOT ACCESSIBLE HERE. TO VIEW A LIST OF FILES AND ACCESS THE FILES IN THIS DATASET CLICK ON THE DOI-LINK ABOV