Air purifiers help reduce airborne viral load.
"$11.6m HVAC (heating, ventilation and air conditioning) infrastructure, equipment, materials, contractual"
https://www.montgomeryschoolsmd.org/uploadedFiles/departments/budget/fy2021/ESSER-1Pager.pdf
That seems low when you consider there are at least 210 schools plus other buildings (less than 55,238 per if you assume all buildings were serviced).
Did anyone notice that their school didn't upgrade their HVAC / fans and ducts? If you're in a classroom, spray a mist into the air. Is it carried away only in one direction? Ex. up a duct, out the hallway, etc?
If the mist hangs on the air, it means MCPS wasted the money.