We are in a multi-story, multi-unit building that uses packaged through-the-wall HVAC systems in each unit. These units often go under the name of "Magic-Pak" or "Comfort Pack" depending on the manufacturer. What's especially unique about these systems is that they are not free standing, but are instead mounted on hardware that is directly integrated into the wall structure and facade of the building.
Here's an example of what this would look like from the outside. In our case the surrounding structure is more of a steel and glass curtain wall, but the principle is the same:
In some cases these systems produce notable low-frequency structure-borne noise that can be a problem, especially when the noise transfers between units overnight. The problem is not universal though (some systems are very quiet), and when there is a problem it does not seem to be correlated with the individual HVAC system's age. This would imply that there are some inconsistencies in the way the HVAC systems are mounted or in the attenuation/dampening characteristics of the surrounding structure.
There are certainly lots of ways to tackle soundproofing, but I do not think the structure-borne noise component in this residential case has a DIY solution. However, finding the right support is very elusive:
- I've contacted numerous HVAC contractors (both commercial and residential) and they all say they don't deal with noise transmission.
- I've contacted numerous soundproofing specialists and they all say they don't deal with mechanical HVAC noise.
- I've contacted the OEMs for the HVAC systems and the related mounting equipment and they won't discuss anything with anyone other than a licensed HVAC provider.
- I've contacted the association and building management and they are not sure if they have any role in this issue as the maintenance of the HVAC systems are the individual unit owner's responsibility.
I also know that specialized acoustical engineers exist, but have been told they only get involved in big-money commercial projects or extremely high-end luxury residential, so that does not seem like an option either.
What sort of entities should a homeowner reach out to in this situation?