You cannot search for a specific room by size (e.g., Kitchen). You can, however, search by Room 1 Length, Room 1 Width, Room 2 Length, Room 2 Width, etc.
In your filters, go to Add a Field, search Room, and the full list will appear to choose from. You can search up to 11 Rooms by Width and Length.
Results may vary based on how the listing agent numbered the rooms. The measurements are searched in metres, not feet.