A device designed to displace the entire air mass within an enclosure (e.g., a room), with uniform velocity and parallel direction, to remove contaminants; it is part of a mobile cabinet or mount. Air is typically drawn from the environment into the system by negative pressure created by a blower; air particles and liquid droplets are removed usually using high-efficiency particulate air (HEPA) filters. Filtered air is then circulated into the enclosure and exhausted or recirculated. The device is intended to provide temporary isolation of patients avoiding contamination and/or to perform procedures in a contaminated-free environment in emergency situations.