Membrane evaporative cooling to 30 degrees C or less: 2. Membrane evaporative air cooling

Microporous hydrophobic membranes were examined for use in steady state membrane evaporative air cooling. The examination consisted of calculating membrane performance as a function of overall heat and mass transfer coefficients already obtained and reported in Part 1 (previous paper, this volume). This performance was compared with that obtained by similar calculations made on existing evaporative air coolers. It was found that the cooling performance of the membrane evaporative air cooler was not as good as that of the existing evaporative air cooler. This is to be expected since the existing cooler has only one resistance, the air boundary layer (ABL), whereas the membrane cooler has the ABL and the membrane resistance. However, the membrane air cooler has advantages, such as appreciably lower water consumption and operation under more sanitary conditions, that is, without intimate conjunction of flowing air and liquid water on solid surfaces.