I have 5 5830s running in my basement, with no additional "high CFM fans" blowing on them. All are running at 69-70C @ 1010/250 stock voltage. No cases. all open.
Ambient in the basement is about 20C.
Parts in bold and underlined was my point. Not a regular setup. Myself, I don't set any special conditions to my computers. They sit in my house in my living areas. You must have a chilly basement.