Found this in the Land Line magazine August/September Issue
https://www.google.com/url?q=http://www.landlinemag.com/Magazine/2013/AugSep/Section3/specing-for-comfort.aspx&sa=U&ei=sxAMUq1uh6CsAa_jgegM&ved=0CBcQFjAH&client=internal-uds-cse&usg=AFQjCNEgHpT9LWCs1HjzNANYnX5U_YrmKw
"Bergstrom...