arsenal vs machine room

arsenal

noun
  • A store or supply of anything. 

  • A military establishment for the storing, development, manufacturing, testing, or repairing of arms, ammunition, and other war materiel; an armoury. 

  • Any supply of aid collected to prepare a person or army for hardship 

  • A stock of weapons, especially all the weapons that a nation possesses. 

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 arsenal and machine room occurred in a corpus of books? (source: Google Ngram Viewer )