wade,
my boss ( i was a meat cutter at the time, before i started construction, told me not to waste my money. His father and father in law were hvac contractors. ( one independent, one company man. )
He is who i use to fix my problems so i trust his judgment. he learned a lot working on the side for these guys.
just another opinion. frequent filter changes.
One hint i've read, is to during the off season (spring / fall ) before changing the filter..... turn to the fan only setting and take your leaf blower and shoot down each outlet.
I haven't done this but it seems like it might work. i would probably fabricate an attachment to fit the registers.
if anyone has a problem with this, please post, i don,t want anyone to do anything without research.
good luck and do your dd.
tom
" The most certain way to assure total victory is to understand that anything less, is a defeat."