Investigation of the characteristics of materials for use in an enthalpy exchanger

This paper investigates membrane materials and their properties for use in an enthalpy heat exchanger. Six membrane materials out of a total of twelve measured samples were evaluated. The first part of this research compares these materials by measuring them and calculating the permeance using a measuring apparatus, and the second part is devoted to the selection of a suitable type of material based on a multicriteria analysis. The results show that a semipermeable membrane based on a crosslinked polymer (sample no. 7) and two types of thermoplastic elastomers (samples no. 11 and 3) achieve better average permeance results than reference sample no. 1 (a paper-based material). Sample no. 7 even reaches more than twice the permeance of sample no. 1. The average permeances of the samples are in the range of 7.27–485.67 ng/s.m ² .Pa, with the highest values for sample no. 7. The uncertainty was determined to range from ± 4.1 to 71.1 ng/s.m ² .Pa. According to the multicriteria analysis, sample no. 7 also achieved the best evaluation result. Shape changes, stretching, shrinking, and deformation of the samples and returning of the samples to their original shapes, which have major impacts on the mechanical construction of an exchanger and its subsequent use in practice, are significant findings. Moreover, importantly, additional reinforcement materials for mechanical strength could be added.