convector vs radiator

convector

noun
  • A space heater that transfers heat by convection; a radiator 

radiator

noun
  • A finned metal fixture that carries hot water or steam in order to heat a room. 

  • A type of antenna. 

  • Anything which radiates or emits rays. 

  • A device that lowers engine coolant temperature by conducting heat to the air, through metal fins. 

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