convector vs kiln

convector

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

kiln

noun
  • An oven or furnace or a heated chamber, for the purpose of hardening, burning, calcining or drying anything; for example, firing ceramics, curing or preserving tobacco, or drying grain. 

verb
  • To bake in a kiln; to fire. 

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