HVAC filter MERV ratings vs pressure drop
Heat pump (GSHP)—- system rated for a MERV 11 filter with a 2 speed compressor and motor —–
I want to temporarily (during construction completion) install a filter at the return grille in the ceiling (to keep any potential dust out of the return ducts) in addition to the normal filter at the AHU.
1) Are there adverse effects to doing this?
2) What combination of filter MERV ratings could I use so there aren’t any adverse affects?
a) How about MERV 8 at both locations.
b) How about MERV 2 at the ceiling and MERV 8 at the AHU?
3) Is there an algorithm for determining what combination of multiple filter MERV ratings are equivalent to a single filter MERV rating?