Wow, Really? A "will i goto hell?"
Yea, You would. OH BUT WAIT NO YOU WONT BECAUSE XYZ WILL FORGIVE YOU IF YOU DO XYZ

My religious hatred aside, there are two things you can do.
Ask for permission and mostlikley get denied and !WATCHED!
Run them with a STEALTHY program (alot have been created for exactly what you need to do) One that will "mine when PC is idle" so that as soon as everyone stops using them, The mining starts, Then as soon as someone touches it, The mining stops.

This will cause you university to have an extra $1000-$4000 increse on thier monthly powerbill, While you kick back raking in $500-$1000/mo
Doing NOTHING because you made it all automated, And stealthed.

On of my friends has control of a Librarys network of computers, Hell it's all CPU's mining, But he's getting a free 375mh/s so he isnt complaining.