专业人士? and STC

Thanks for your reply.

Maybe I asked the builder designated closing agent for attorney referral. The builder suddenly became reponsive. They will arrange an acoustic engineer to investigate the noise issue. Again, this person is also referred by the builder. I guess he is the 专业人士. Would he be able to tell me the STC level? Is there anything else I should be particularly watch out for when he comes with the builder to do the examination next week?

It sounds like you may be familar with soundproofing. I received following advise regarding how to fix the problem. Wonder if you have any comments: (單身老貓, I am sorry that this part of the post does not have any legal aspect)

If you can't do anything to the HVAC units themselves, you could add another layer of 5/8" drywall to your ceiling using the Green Glue visco elastic damping compound applied to the backside of the new drywall. You would still use screws to attach the drywall with the Green Glue sandwiched between the 2 layers of drywall. I would recommend at least 2 to 3 tubes of Green Glue per sheet of drywall. You apply the Green Glue with a caulk gun quart sized. You would need to do the entire ceiling of the area where you have the problem. The Green Glue will damp the existing layer and the new layer of drywall and will stop at least 60% of the noise that comes through that ceiling.

If you can do something beneath the HVAC units then we carry 4' X 6' recycled rubber tile that could be fitted underneath the units and they would give you more isolation from the ceiling. I personally think that the Drywall application would be your best bet.