Is it better to have smaller or larger filter for exhaust fan?

I've been using carbon filters from amazon rated at 170m³/h but now i'm looking to get a better quality filter for my 4 inch 190m³/h duct fan because the ram filters only last 2 runs

From what i read you want the filter to be rated at 133% (one third) higher than the rating of the fan which is 250 m³/h

The filters i want is the rhino or AC infinity carbon filter but they're rated at around 300m³/h
So my question is, would it be better better to have a filter rated 10m³/h lower than the fan or a filter rated 50m³/s higher than the recommended 133%?

Thanks

Larger filter.

PadawanWarrior said:

Larger filter.

Click to expand...

Thank for quick answer, very appreciated

Be a size queen. Get the biggest filter you can

Nothing wrong with an oversized filter. Bigger the better IMO.

I've tried AC infinity 6" and 6" XL both were garbage in my opinion. I like the idea of these small light filters but if they don't filter scent then its pointless. I got another can 660 , its big and heavy but it works great.

Better companies give you a data sheet with min/max flow rates. If you're outsuide the range of that it won't work properly. If the filter is much larger than the fan, the flow is too low and it doesn't perform.
Dont forget the flow impedence of the added filter. Thats decreases flow of the fan.

Also each foot of duct reduces the efficiency of fan.