engine room vs machine room

engine room

noun
  • A compartment on a ship in which the engine machinery is located. 

  • The front row. 

  • The midfield. 

  • The pair of locks in a team. 

  • The source of power in a team or other group. 

machine room

noun
  • A limited-access room in a larger building dedicated to HVAC equipment and other machinery. 

  • A dedicated room for computers and related data processing equipment, often having a raised floor, abundant and dedicated air conditioning, and specialized power supply and fire suppression systems. 

How often have the words engine room and machine room occurred in a corpus of books? (source: Google Ngram Viewer )