**5. Conclusions**

A scenario with a virus-infected patron sneezing in a restaurant was modeled and three vent configurations were compared. The first two configurations had supply and return vents on the ceiling and one configuration had supply vents parallel to the return vents and the other with staggered supply vents. The third configuration had supply vents on the wall. It was found that the percentage of airborne particles was lowest for the staggered supply configuration. The percentage of exhausted particles was also highest for the staggered supply configuration. Hence, the staggered supply vent configuration was considered as the one with least risk of virus transmission. The effect of increasing air changes per hour was studied by comparing 6, 9 and 12 ACH for the staggered supply configuration. The percentage of airborne particles reduced with increasing ACH.

A scenario with multiple restaurant patrons talking was also modeled. A comparison of the parallel and staggered ceiling supply configurations with talking showed that percentage of airborne particles was similar in both cases but the percentage of exhausted particles was higher in the staggered supply case. This supports the argument that the staggered supply vent configuration is the safest. A summary of the results is given in **Table 2**. Talking particles larger than 5 *μ*m are considered as aerosols as they are smaller than most droplets and behave similar to aerosols.

It was found that aerosols (0.5 *μ*m–5 *μ*m) being lighter, rise and were carried by the airflow and droplets (5 *μ*m–150 *μ*m) being heavier were not affected much by the airflow and settled. Sneeze particles consist of a majority of droplets. Hence, most of the sneeze particles were deposited on the floor and not more than 10% were exhausted. Very few sneeze particles were deposited on the adjacent tables (placed 2 m apart). On the other hand, talking particles mostly consist of aerosols. The percentage of exhausted particles in the talking scenario (about 20%) was higher than the sneeze scenario. In case of talking, a 2 m distance between tables may not be sufficient.


*Assessing Ventilation Strategies to Reduce the Spread of Pathogens in Restaurants DOI: http://dx.doi.org/10.5772/intechopen.109634*

**Table 2.**

*Summary of particles airborne, exhausted and deposited for sneezing, ACH and talking cases.*
