Laboratory and on-site measurements of natural ventilation rate with solarchimney system

Development of a unique measuring unit for airflow volume within the vertical shaft of naturalventilation system with solar chimney with theresults of laboratory test and on-sitemeasurement is presented. As it was considerednecessary to make a continuous, siniultaneousmeasurement of a fluctuating air flow within thevertical shafts towards solar chimney, thesimple measuring unit was devised. This unitconsists of pressure detector and data logger tobe installed at several locations. First therelationship between the air velocity and thepressure difference was obtained in thelaboratory test. Then this device was installed inseveral different locations near the grillstowards the vertical shafts to measure thepressure difference from which the air flowvelocity could be calculated using therelationship obtained from the laboratory test.Based on the pressure difference measured bythis device, the air flow velocity at all grillestowards the vertical shafts of a real buildinghaving natural ventilation system with solarchimney could be inferred to obtain the air flowrates, where sometimes reverse flow occurs.The results of the on-site measurement agreedquite well with the laboratory test results so thatthe effects of the natural ventilation system withsolar chimney could be estimated. Thismeasuring unit can be used for estimating airflow volume within the underground pit as well.