EXP COVID-19 Offices White Paper

PATH FOUR (FECAL ORAL) TRANSMISSION To protect against transmission risk from the sewer system, floor drains must have trap primers or barrier type trap seal protective devices (i.e., to prevent trap seal evaporation and the backwards flow of sewer gases). If trap primers or trap guards are not installed, the WHO suggests preventing dried-out floor drains by regularly adding water (every three weeks depending on climate) so that the water seal works properly. As noted earlier, the primary source of this transmission path is from what is referred to as the fecal cloud which is created when we flush water closets. The WHO also proposes as precautionary measure to flush toilets with closed lids. Unfortunately, commercial facilities in the USA do not have lids on water closets. It follows, it is suggested high ventilation rates and airflow patterns that draw contaminants to the WC exhaust is important. The bathroom areas must be held at a negative pressurization to other low risk areas. If exhaust can be modified to exhaust air at the water closet bowl, it would be of value. In addition, EXP proposes adding UV systems in the restroom environment is positive upgrade. Upper Air UVC is a good option. However, an EXP developed UVC concept may be able to stop the fecal cloud at its source. As shown in the sketch below, UVC fixtures installed in each stall would be interlocked with the stall door and occupancy sensor to increase bulb life and protect occupants. Indicators would show when a stall has been treated.

Figure 36. Restroom WC stall Far-UV concept

SOLUTIONS TO EFFECTIVELY COMBAT COVID-19 IN OFFICES

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