Convection Flows from an Overhead Projector and a Data Projector

When room ventilation is based on the stratification or zoning strategy, the ventilation airflow rate is determined on the grounds of the convection flows of the heat sources. Thus, inthe design phase of office ventilation, the convection flows of common office devices shouldbe known. Especially, to correctly dimension the ventilation air flow, it is important to knowthe volume flow rates. However, even if the convective power of an office appliance isknown, the cooling fan makes the prediction of the characteristics of the convection flow verydifficult. Therefore, direct measurement data is needed. In this study, the convection flows ofan overhead projector and a data projector were examined. Cross sections of the velocity andtemperature fields were measured and analyzed to obtain the volume and momentum flowrates.