Restaurant exhaust fan

Hi there - I'm in Los Angeles. I have a commercial space and I don't have to worry about sound isolation as far as disturbing the neighbors is concerned, however, there is a pizza joint in my building and their very large commercial exhaust fan sits on the building's roof directly over my space. The fan from the motor on that thing sends vibrations through the wood framed ceiling and I hear a low rumbling when it's on, seems to be around 200-300Hz and below. Has anyone dealt with these types of exhaust systems - I've been told they are typically installed with springs or insulation but for whatever reason this seems not to be enough here? Is there some kind of dampening or isolation that can be done to the unit itself so that it does not couple to the ceiling joists? Can I hire someone to stand there 24/7 and hold it in his arms while wearing shoes made of neoprene? Any takers?? Thank you for your help!

if you check out Mason Industries, they specialize in isolation frames that could decouple the roof unit but you probably would need to decouple the duct from the unit as well as possible decoupling/damping the duct depending on how much vibration is coming from the air flow through it.

I will check that out. You folks are so helpful around here!