Visualising Full-Scale Ventilation Airflows PDF

Notes the difficulty of clearly visualising air currents, even with the use of tracer particles. Describes a system using the schlieren technique, a form of optical flow visualisation keyed to thermal differences in the flow which permits the clear visualisation of air currents. States that the direct observation of full-scale HVACR air flows by this technique has been shown to be feasible and useful. The key innovation is the use of a large grid and a small lens in place of former limiting optical elements. Provides some full- scale schlieren photographs of air flows in typical situations involving people and notes the new information they reveal. Concludes that a new tool is now available for full-scale ventilation and indoor air quality studies, validation of computational results and the diagnosis of air flows created by all types of HVACR equipment. Mentions work on developing portable equipment.