Fan over sump?

[Son Of Skyline]

Would a fan blowing over a sump in a cabinet be as effective in reducing tank temps as a fan blowing in the hood? We're talking possibly reducing temps in a 120gal by 3-4 degrees? I have a fan in my hood now but it's not doing the job by itself. My canopy setup doesn't allow any additional fans however, so I'm wondering if I should bother buying a cheap house fan and sticking it over my sump instead, or shell out more dollars for a higher powered, thin fan to replace the one I have now in the hood.

Cheers..