INCOMPLETEMIXING IN VENTILATEDAIRSPACES. PART I. THEORETICALCONSIDERATIONS1

Abstract

The heat and moisture balance equations for a ventilated room cannot be solved without making some hypothesis concerning air distribution within the airspace. The usual approach is to assume complete mixing which equates the thermodynamic properties of the exhaust air to the average thermodynamic properties of the bulk airspace. A theoretical analysis suggests that departure from complete mixing may be caused by the formation of multiple flow regions within the airspace, or by short-circuiting of supply air to the exhaust outlet. This report will alert designers of livestock buildings to the possibilities and consequences of various forms of incomplete mixing.