Final answer:
A metal grid of inverted tees in a suspended ceiling is used for supporting acoustical tiles, which improve the acoustics of a room and provide access to overhead systems.
Step-by-step explanation:
The metal grid of inverted tees used in a suspended ceiling is for supporting acoustical tiles. These grids are a crucial component of drop ceilings or suspended ceilings, which are often used in offices, schools, and other commercial buildings for both aesthetic and practical purposes.
The inverted tees provide a modular framework onto which the acoustical tiles are placed. These tiles serve the purpose of improving the acoustics of the room by reducing noise levels, absorbing sound, and preventing echo. The grid also allows for easy access to ductwork, wiring, and plumbing that may be routed above the ceiling, without needing to dismantle the entire ceiling.