“…According to “Ending Isolation and Precautions for People with COVID-19: Interim Guidance” of the WHO, the negative pressure isolation unit can be formed by using the existing 3 M (10 ft) outdoor etiquette tent skeleton and some PVC coated fiber cloth skin from the market, replacing one or more local transparent PVC films, making proper air tightness enhancement, adding necessary air inlets and outlets, and taking material reinforcement measures. No matter whether there is a fresh air supply or not, the isolation unit of the infection department needs a special air distribution; therefore, the air flow from the top to the bottom, or from the height of the medical staff to the head of the hospital bed, and the occurrence of turbulence are minimized [ 9 ]. Therefore, the best way is to undertake laminar flow organization.…”