The Surnames LOEWENHEIM, LOWENHEIM, LÖWENHEIM are far less common than similar names such as LOEWENTHAL & LOEWENSTEIN. They are mainly associated with families of Jewish origin from Germany and Hungary.
This is a link to a worldwide One-Name Study on LOEWENHEIM, LOWENHEIM, LÖWENHEIM:
http://freepages.genealogy.rootsweb.com/~pnlowe/loewenhe.htm