aerator vs hand fan

aerator

noun
  • A device which mixes air with a substance, particularly soil or a liquid. 

  • A fumigator used to bleach grain, destroying fungi and insects. 

  • A device used for charging mineral waters with gas and in making soda water. 

hand fan

noun
  • A hand-held device designed to be waved back and forth in order to induce airflow for the purpose of cooling the user. 

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