@fergal_whatever @FinchTH Have you considered upper room UVGI? It seems to be far more mature and probably less expensive than far UV and capable of achieving very high equivalent ventilation rates.
@fergal_whatever @FinchTH 你考虑过楼上的 UVGI 吗？它似乎比远紫外线更成熟，可能更便宜，并且能够实现非常高的等效通风率。