Is there a difference in the airflow between a Merv 7 -vs- Merv 11?
These are the filters http://www.airguard.com/pleated.html I'm talking
about in case brand makes any difference. I'm looking at the "DP Max"
(merv 7) vs "Powerguard" (merv11)
I see they have an efficiency rating, whatever that is. Does a Merv 11
restrict more air than a Merv 7?
I'm looking for good airflow and a "HEPA type" filter combined.