Honestly no idea, they get heavy use and so bags are replaced as necessary and filters replaced often enough.

Maybe something in the earth, lime content perhaps?

The pads don’t hold their quality and the motors just kinda die with little warning they just burn themselves out.

Tried others hoovers based on Henry but they were terribly designed, poor quality and somehow more expensive.

Industrial cleaner. Last job we had a fleet of Henry’s and not a single issue in 3 years. Didn’t even replace the pads. Gone through 5 Henry’s this past year alone on a new job. Don’t make them how they used to.