RE:A questionJohn I posted this yesterday. It's an air and surface study for Covid but the net conclusion was "
All the air samples collected from contaminated areas were positive" https://www.sciencedirect.com/science/article/pii/S0048969720340626
BioCloud is supposed to cover 1000 sq ft . Anything more and you need two so your 30x30ft example only needs one unit.
I don't know what that means when it is connected to an HVAC though. I presume it would cover that entire space so much mote than 1000sqft... you'll just have more people to test on a positive.