1.   ...badly ventilated rooms.

2.   She opened the windows to ventilate the room.

3.   The room was adequately ventilated.

4.   And if worst comes to worst, ventilate the room by opening windows twice a day to release the water vapor.

5.   But in warm weather they ventilate that room nicely.

6.   There is not much you can do about the studs showing dirty, except to ventilate the room occasionally to reduce the water vapor.

7.   You ventilate the room.

8.   A security guard who spoke on condition of anonymity said no one would be allowed back in until all rooms were ventilated.