US Patent 11859864 Particulate and virus barrier

An air plenum provides protection from viruses and particulates to a user located beneath the air plenum. The air plenum has a housing with a fan centrally located within the housing. Low-velocity air is emitted downwardly from the fan through a perforated screen on a lower side of the housing onto the user. A slot diffuser extends around a lower periphery of the housing and emits high-velocity air downwardly to form an air curtain around the user. The higher velocity air of the air curtain reduces the ability of unwanted particulate matter to enter the area that is below the perforated screen.