Experimental Investigation of an Integrated Wind Induced Ventilation and Evaporative Cooling System
Abstract
Low energy systems such as earth-air tunnels (EAT) and evaporative coolers are effective ways of reducing the energy demand for building ventilation and cooling. Direct evaporative coolers are effective in regions of low humidity. Their performance can be enhanced by coupling them to an EAT as pre-coolers. The reliance on electrical fan power can be reduced by using low pressure evaporative coolers and capturing wind when available. The paper reports on an experimental system developed to simulate a wind induced low pressure evaporative cooler, using mains pressure misting nozzles which is open to a 10.1 m2 room with window opening. A section is included in the duct to simulate the pressure drop in EAT. The system performance is evaluated for different wind speeds, ambient conditions, and pressure drops. The results show that significant cooling and ventilation can be achieved with this combination. They also demonstrate that the prevailing wind velocity can play a major role in inducing air flow in an EAT and hence reducing the reliance on mechanical fan usage.