Thanks for the reply Keith. Loose-fitting PAPRs are definitely the most comfortable to wear for porlonged time, but I'm not convinced that we can convince the general public to wear them - they're big, bulky, expensive, and putting them on is a hassle.
I'm thinking more along the lines of a...
I'm trying to get a rough idea of the optimum filter size & configuration for a face mask in different breathing conditions (sitting, walking, exercise etc.). I'm also trying to determine if it'd make sense to boost the airflow in the mask with a fan.
I'm struggling to find good resources on...