Another company installed these new (tore out perfectly good basement Otis tractions) and now they are no longer in business. The piping is isolated pretty good (fire caulk at wall penetrations) and the power units do sit on rubber isolation pads. I was called in for my opinion and to see what we could do. I am going to use Otis style thick platen plate isolation pads, air bladder mufflers, and isolation couplers to see if we can make it better (it should), but I still think it's internal to the power units themselves. They just have a hum to them like a damn transformer hum as soon as they start up. Even when just bumping them up on hoistway access they are LOUD.
