English to Italian Tech/Engineering Mechanics / Mech Engineering

When the indoor unit is installed where the inside of the ceiling is 30°C (86°F) RH80% or greater, the dew point temperature of the outer perimeter may become higher than the cabinet surface temperature and moisture will condense on the surface of the cabinet and water drops may fall inside the room.
→Refer to Fig.A
In addition, the humidity may vary considerably the same as when the inside of the ceiling is close to hermetically sealed and used as the outside air intake path.

non credo che "close" in questo caso stia per "sigillato" perché sennò altrimenti dovrebbe essere "the ceiling is closed and hermetically sealed". In ogni caso, anche se close to sia letteralmente inteso come "vicino a" non mi suona molto bene in questo contesto. Un'idea per renderlo più carino stilisticamente?

grazie in anticipo