Throttling Diablo Miner

[splatster]

What I need to do:
Throttle down the speed of Diablo miner to a speed that won't affect user experience.

Why I need to do it:
As head of IT at my place of work, I have a number of computers under my control, all running various OSs, thus my choice to use Diablo.  My problem is that these computers need to be functional.  I am unaware of any flag of Diablo that would allow me to throttle the hashing down to something that would not need the fans to be running constantly nor would it cause any noticeable difference in the user's experience.

I want answers, not criticism even if you think what I am trying to do is stupid, not practical, etc.

Thanks to those who can provide any help.