Dryer Vent Getting Clogges

[Charles Heistand]

Hello everyone!

Have a question regarding dryer vents at our 6 unit complex. The dryer vent to the outside is consistently getting clogged and appears the lent doesn't blow through. This happens on all 6 units and it doesn't matter if the tenants clean the inside lent trap or not this still happens in about 3 weeks time. When we purchased the building in July 2021 we had everything professionly cleaned and they were spotless and then in 3 weeks time the outside looks clogged again like they were never cleaned.  The dryer vents on our main house look completely different than these where ours have lovers that open instead of having a grate for it to blow through. Is it possible these are the wrong type of vent when someone replaced them at some point in the past where these are exhaust vents and not dryer vents? Is there something that I'm missing on this? I try to clean them out when I'm at the building but doing it every 3 weeks seems excessive since at my main house I never have to do this. Would it be the tenants responsibility to clean the out?

Any ideas or suggestions would be much appreciated!