Commercial wind towers for heating and cooling based on climatic conditions

Commercial wind towers are passive ventilation technology based on traditional vernacular wind towers of the Middle East, particularly in climates of hot, arid conditions. By manipulating pressure differences and the buoyancy effect, caused by wind driven flow and density stratification of internal air due to temperature differences, adequate levels of ventilation can be provided to buildings utilising wind towers in a low energy process. This negates the use of mechanical air-conditioning systems which require substantial amounts of energy. One current limitation of commercial wind towers which exists is the inability to condition the incoming air for thermal comfort to occupants. This relates to cooling demand in hot climates and heating and cooling demand in temperate climates. At present, commonly used methods to provide thermal comfort rely on energy intensive mechanical processes to cool or heat the incoming air which is not sustainable given pressure to reduce energy use and global greenhouse gas emissions. Low energy methods for cooling and heating of air passing through a wind tower have not yet been comprehensively explored. A cooling system utilising the combination of heat pipes and a heat sink has been developed and incorporated into a commercial wind tower. This system has been analysed using CFD and tested experimentally in a hot climate and showed positive results in reducing the temperature of the incoming air. A heat recovery system utilising a rotary thermal wheel to transfer the thermal energy from the exhaust airstream of a wind tower has been developed and incorporated into a four-sided commercial wind tower.