air out vs steam up

air out

verb
  • To expose to air; to leave open or spread out, as to allow odor or moisture to dissipate. 

  • To throw passes, especially long and high passes. 

  • To discuss in the open; to address an issue or conflict that has long been avoided. 

steam up

verb
  • To become coated with condensation. To fog up. 

  • To become steamy. 

  • To bring (a steam boiler) up to working steam pressure. 

How often have the words air out and steam up occurred in a corpus of books? (source: Google Ngram Viewer )