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Fibrous materials, such as cellulose papers, fibres, or textiles, are regarded as potential evaporation materials used in evaporative cooling systems. The fibrous material’s wettability and evaporation characteristic have significant influences on heat and mass transfer performance of evaporative cooling systems. This paper studied the wicking performance of selected fibrous materials including cellulose/PET fibre, Coolmax fabric and wood pulp paper by numerical modelling and dedicated experiment based on transient weight and optical measurements. The effect of evaporation on the performance of wicking rise were analysed in depth using the obtained experimental data. The measured data show good agreements with the predicted results, within ± 6.67%, 7.47% and 3.78% errors for the three types of materials, respectively. The microstructure parameters that control water diffusion performance of porous materials, i.e., permeability to effective pore radius ratio, were found to be highest for cellulose/PET fibre followed by Coolmax. Additionally, the study compared water evaporation rate of the selected materials by a few validated preliminary tests operating under various ambient air velocities and surface temperatures. Coolmax and cellulose/PET fibres were found to have similar higher evaporation rate than wood pulp paper. This paper presented numerical and experimental approaches for accurately characterising and differentiating wicking and evaporation performance of fibrous materials which would contribute to optimise evaporation materials for evaporative cooling systems.

Recently there has been growing interest in regenerative evaporative coolers (REC), which can reduce the temperature of the supply air to below the wet-bulb of intake air and approach its dew-point. In this paper, we designed, fabricated and experimentally tested a counter-flow REC in laboratory. The REC’s core heat and mass exchanger was fabricated using stacked sheets composed of high wicking evaporation (wickability of available materials was measured) and waterproof aluminium materials. The developed REC system has a much higher cooling performance compared to conventional indirect evaporative cooler. However, the decision to use the REC for China buildings depends on a dedicated evaluation of the net energy saved against the capital expended. Such an evaluation requires the hourly-based data on the availability of cooling capacity provided by the REC for various climates. The paper used an experiment-based method to estimate the cooling capacity and energy savings provided by the proposed REC for China’s various climates. By using the experimental results and regional hourly-based weather data, the energy saving potential of the REC against an equivalent-sized mechanical air conditioner alone was analysed. The results indicate that, for all selected regions, the REC could reduce 53–100% of cooling load and 13–58% of electrical energy consumption annually.