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!
Most of that model use a recip compressor. Only the 5 ton uses a scroll. Sometimes they make more vibration than the recip. Might have to do some detective work to see which machine is the culprit. Or could be a bad compressor.
At our office, the single A/C is 2 floors above mine. In cool weather I can hear the thing some on. In hot weather I can't. I'm guessing things are just stiffer in the cold plus the machine strains more from cool oil. Is there any difference in temps when you hear more noise?
Thanks for the response BaldLoonie. It's interesting you mention that about the scroll vs. recip compressors, I noticed that too when I looked at the spec sheet. I had always thought that scrolls were quieter and vibrated less, but after reading some old posts on this forum it seems like some other people noticed vibrations transmitted through refrigerant lines when upgrading to a newer scroll unit. It actually makes perfect sense, because my next-door neighbor recently moved in, aligning with when I started noticing the noise. I have a 4 ton unit, and their condo is bigger than mine, and since the YCJD doesn't come in a 4.5 ton size, logic would only dictate they'd have a 5 ton unit with a scroll compressor.
I don't think it has anything to do with cold weather, because it was in the high 80s/low 90s that evening. I'm going to try and get back up on the roof so I can take some pictures, and maybe do some detective work as you said. It's really tempting to start throwing disconnects to see which one is causing the noise, but I don't think that would go over too well with the neighbors