закрытое помещение

см. тж. в закрытом помещении

Gaseous agents are indispensable for disinfecting rooms or other large enclosed spaces.

The vehicle may have a body (an enclosed compartment for people or commodities).

Architectural acoustics is the science of planning and building an enclosure (дальше приравнивается к room) to ensure the most advantageous flow of properly diffused sound to all listeners.

Источник: Русско-английский научно-технический словарь на Gufo.me