furnace vs ventilator

furnace

noun
  • A device that provides heat for a building; a space heater. 

  • A place or time of punishment, affliction, or great trial; severe experience or discipline. 

  • Any area that is excessively hot. 

  • An industrial heating device, e.g. for smelting metal or baking ceramics. 

verb
  • To heat in a furnace. 

  • To exhale like a furnace. 

ventilator

noun
  • A device that circulates fresh air and expels stale or noxious air. 

  • A machine that moves breathable air into and out of the lungs of a patient who is unable to breathe sufficiently. 

  • Some behaviour or happening that relieves a tense atmosphere or situation. 

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