My furnace filter trick from a 30 year HVAC guy

I had a repairman out last month for a blower issue on my 15 year old Payne furnace. He asked what filter I was using and I showed him the cheap fiberglass one from Home Depot. He told me those are basically useless and let too much dust through, but the problem is most people buy the expensive pleated ones that are too restrictive and burn out the motor. He said to get a MERV 8 rated filter, not higher, and change it every 60 days during heating season. Since I switched to that, my electric bill dropped about 15 bucks and the air feels cleaner. Anyone else get told something that goes against common advice?

3 comments

3 Comments

patricialee1mo agoMost Upvoted

Honestly, that MERV 8 advice is spot on. I ran a MERV 11 for years thinking it was better, but my electric bill was consistently higher and my furnace ran longer cycles. Switched to a MERV 8 and changed it every 2 months during winter, and I noticed my utility bill dropped by about 12 bucks a month. The air feels plenty clean too, not dusty at all. Ngl, the cheap fiberglass ones are basically glorified lint catchers, they do nothing for dust.

wendysanchez1mo ago

$12 a month is basically a free burrito for admitting you were wrong about filters lol.

smith.anna1mo ago

Read something from an HVAC guy once who said the real issue is people treat filters like they're buying tires for a sports car. He explained that higher MERV filters are meant for commercial buildings with big fans, not a standard home furnace. It made sense after I thought about it, most houses just don't have the airflow to handle that extra resistance.