Computational analysis of a wind tower assisted passive cooling technology for the built environment

This work investigates a novel closed-loop thermal cycle containing cylindrical heat pipes integrated within a roof-mounted circular wind tower to achieve internal comfort. The water-filled copper heat pipes having an outer diameter of 20 mm were systematically arranged in a horizontal orientation. Water was used as the working fluid instead of synthetic refrigerants in order to make the system carbon- neutral alongside maintaining the indoor air quality of the built environment. The three-dimensional Reynolds-Averaged Navier-Stokes (RANS) equations along with the momentum, continuity and energy equations were solved using the commercial FLUENT code for velocity and pressure field simulations. Using the inlet wind speeds varying from 1 m/s to 5 m/s, the results of the study showed that the proposed cooling system was capable of meeting the regulatory fresh air intake requirements per occupant of 10 L/s. In addition, the results showed that a passive cooling capacity ranging between 6 K and 15 K depending on the operating configuration. The findings of the study were validated by comparing the results with similarly analysed wind tower structures found in previous literature. The present work successfully classified the sustainable operation of natural ventilation systems in delivering energy-free cooling in regions encompassing hot and moderately humid or humid climatic conditions. The technology presented here is subject to an international patent application (PCT/GB2014/052263).