We can. Half a lifetime ago, I replaced the HVAC in my house and one of the add-ons, which I bought, was a UV disinfecting lamp. I have no idea if it was effe

We can. Half a lifetime ago, I replaced the HVAC in my house and one of the add-ons, which I bought, was a UV disinfecting lamp. I have no idea if it was effective or snake oil but it was on offer. Hospitals and medical labs have (demonstrably effective) UV lights in their HVAC systems.