You would be fighting the natural convection flow (heat likes to go up). It would be better to install the fan as a suction fan to suck the heat out. Air flows just the same - but with the aid of heat. Colin K7FM -- FAQ on WWW: http://www.contesting.com/FAQ/amps Submissions: amps@contesting.com Administrative requests: amps-REQUEST@contesting.com Problems: owner-amps@contesting.com