Elevators are a critical element of "last mile" transportation infrastructure in high population density environments whose carrying capacity is severely constrained by recent social distancing recommendations. The design presented here aims to mitigate this loss by employing a system of disinfected downward airflow to effectively reduce the social distancing length scale. In addition a system to provide ultraviolet light disinfection of surfaces is employed to reduce indirect transmission.
As illustrated in figure 1, the downward airflow system consists of sensor directed, patterned airflow from an upper, ceiling level air handling array to form what amounts to an air curtain between passengers so that infectious particulates emitted by a given passenger will be deflected and end up at or near floor level before they have a chance to reach any other passenger(s). After collection of air through an air permeable floor and/or floor level air ducts the air is directed through suitable filtering and disinfecting stages before returning to the upper air handling array. Optional downward directed columnated lighting can be used to indicated air curtain location(s).
As illustrated in figure 2, the ultraviolet light flash disinfection system engages when, during normal usage, the elevator happens to be empty. Alternately a minimum time between flash cycles can be enforced with suitable audible and or visual alerts to direct passengers to exit the elevator to allow a subsequent disinfection cycle to engage.
Both the disinfected downward airflow and ultraviolet flash designs can be implemented with current technology and should be relatively straight forward to retrofit into existing infrastructure and while the current COVID-19 crisis is likely to be resolved in the near future, widespread adoption of this design could have a lasting impact in reducing transmission of disease in general and thus save lives and money year after year long after "social distancing" becomes nothing more than a fading memory.