Many folks have added high volume external in-line fans that are much quieter and quit using the regular fan at all. If you are still under warranty you might want to go for the replacement but ~$100 for a fan would be cheaper and faster, and much quieter, if you are out of warranty.
I have a Vivo 195 CFM that is inadequate for smokey cuts but the bigger fans usually have 6" hoses that need to be compensated for. A bit of searching for in-line fans will find all sorts of discussions about brands prices and systems,