For office buildings with an open-floor layout, some workstations may be over-ventilated and others may be inadequately ventilated, even though the total ventilation (outdoor air supply) rate may be adequate. This is because information related to workstation layouts rarely is available when designing the ventilation system. In addition, workstation layouts may be changed as the use of the space changes. To ensure that every workstation is adequately ventilated, building managers and designers need to know the influence of various design parameters, such as the types and design layouts of supply air registers and return air grilles on the performance of a HVAC system in a workstation.