economizers

/IY0 K AA1 N AH0 M AY0 Z ER0 Z/
noun
  1. 1

    A person who avoids waste

  2. 2

    A heat exchange device in a boiler that improves efficiency and saves fuel

Source: https://en.wiktionary.org/wiki/economizer, https://en.wiktionary.org/wiki/economizers