Of course, not all activated carbon filters are created equal. That's just a fact. Some work better than others. (Don't ask me to rate every mfg cuz I aint no expert) Some work LONGER than others. They wear out ... or their microscopic pores become saturated and it can hold no more.
Whatever. I use a CanFilter66 $200. It will be replaced every 12 months. I use a Elicient 8" 750cfm inline fan with a TV2 temp/speed controller. I exhaust through my roof vent in the attic. I'm at week 7 of flower. 8 large plants, including the super stanky Lemon Skunk. ZERO SMELL outside or inside my house.
In my opinion: if you are having smell issues, you either ... 1) have the wrong equipment. 2) have the right equipment hooked up wrong.
Your post is MOSTLY accurate.
Im a running a fresh canfan 33 venting out through my attic.
Im also running an air lazer ozone generator at the same time.
My room is pretty much air proof except for a small vent at the bottom of the floor thats needed for proper air circulation.
With the use of 2 odor removal devices, It never takes away all the smell.
I would say its 80% effective.
If you say your house is 100% odor free,
I wont be able to believe that.
Your probably used to the smell is all.
Ill bet if someone walked into your house, they would be able to pick up on the smell, even if its a hint of a Cannabis odor.
I have been in many grow houses in my time, and I can ALWAYS pick up on the scent.
If you got it Zero'd down, then more power to ya!! Good job! Consider yourself "Lucky"