Issues with compressor vibration in condo
I recently moved into a new construction condo in the greater Boston area. Due to the design of the building, the roof above my condo is the only part that's flat, so all 26 condensing units for the entire building are on top of my condo. When I realized this (before I bought it) I made the sale contingent on the developer taking measures to prevent vibration issues in the condo. They installed vibration isolation pads, and after they did I requested that they turn on all the units with me in the condo so I could listen and make sure it wasn't an issue. They turned on at least 20 of them (verified by me up on the roof) and I couldn't hear a thing in the condo, so I went ahead with the purchase.
Fast-forward to yesterday. I started hearing a dull, loud, pulsating noise that definitely seemed like it was coming from a compressor. It ran for a while, but cycled on and off later. The problem seemed to be coming from 1 or 2 units, not all of them (thank god). I was running my AC at the time, and I couldn't hear a thing from my unit. I climbed up on the roof, and everything was the same as before, and I managed to narrow down which might be the problem units (since only a few were running).
The condensers are York YCJD (http://www.york.com/residential/prod...unit-ycjd.aspx) units. They range from 2-5 tons in capacity.
My main questions are 1) Is there anything that might have caused one of these systems to become more noisy?
and 2) In your experience, what are the best products/methods to solve this problem? Doing some internet searching, it seems like there are many different products out there that try to isolate vibration in a variety of ways. Which way is most effective?
I've contacted the developer but he's currently being unresponsive, and he may or may not be able to solve the problem. Trying to get in contact with a neighbor at this point is hard because I don't know which compressor is the problem and not all condos are occupied yet.
Getting access to the roof is a bit of a pain, but I figure I'll have to do it a few more times anyway, so I can post pictures if you think they'd be helpful!
Thanks for any insights you might have!