Which term is used to describe plumbing systems in private bathrooms of hotels or apartments?

The term that best describes plumbing systems in private bathrooms of hotels or apartments is "Private Use." This designation is appropriate because these bathrooms are intended for personal use by individuals or guests, distinguishing them from facilities that are accessible to the general public.

In a hotel or apartment, the bathroom serves a specific private need, aligning with the nature of "Private Use." This implies that the plumbing is installed for individual occupants rather than for public access, as would be the case in restrooms found in a commercial setting.

While "Residential Plumbing" could seem applicable, as it encompasses plumbing in residences, the context of hotels or apartments means that "Private Use" more accurately captures the specific function of those plumbing systems within non-public settings. Commercial Plumbing generally refers to plumbing systems in businesses and public places, which does not apply to the individual use context. "Public Plumbing" is typically related to facilities accessible to everyone, like those found in parks or community centers, making it irrelevant in this context.