No, not much. While HVAC systems do offer some prevention, it is far from ideal because an HVAC system will most often not intervene where the real mode of transmission is occurring. The closer people are to each other in an indoor space the lower the the intervention and mitigation effect of an HVAC system. That is because HVAC air vents are designed for broad dispersion rather than focused stream that intervenes in close-contact settings. In contrast, prevention based on the crosswind technique does work very well, and when added to an HVAC system, greatly enhances mitigation performance.