Thermal diffusion of water vapour in porous materials: Fact or fiction?

This paper resolves that contradiction. A critical analysis of the investigations supporting the occurrence of thermal diffusion reveals that all are flawed. A correct reinterpretation of all measurements allows concluding that no consistent nor significant thermal diffusion can be observed. This brings these investigations in line with their earlier opponents. This conclusion also agrees with thermodynamics, which confirms the actual existence of thermal diffusion, but also indicates its negligible magnitude. It can in conclusion be stated that thermal diffusion is of no importance for building science applications, leaving vapour pressure as the sole significant transport potential for the diffusion of water vapour in porous materials.