'HEPA filter systems cost $1,000 to $4,000 with installation'

KITCHENER — It would cost nearly $1.7 million — plus another $600,000 in annual costs — to outfit all remaining classrooms with HEPA filters, the Waterloo Region District School Board says.

Overall, staff are not confident that deploying a HEPA unit to each classroom is feasible from a cost or procurement perspective

Cheap for you, perhaps.

Dunno why you need to start going to the insult route. I thought we were just exchanging ideas from different perspectives.

I'll compile a list of high quality published research

Looking forward to it.