To view and edit a specific room, go to
Ribbon: DM HVAC->Rooms and Walls-> 
Query Room
Pulldown Menu: DM HVAC->Building Definition->Rooms->Query Room
You will be prompted to identify which room on the drawing to be queried.
Specify point inside room to query:
The Room List dialog box will appear.
Changes can be made to the room in the same way as when using the Edit Rooms command.