Network Rendering/Render Farming

[theAVator]

So, I'm kinda new to some of this. (enough to be dangerous and yet also not sound stupid-hopefully  )

I've got some pretty large animations to render for a project - First animation is ~7000 frames @ 24fps, even more if I want to do 30fps. The next three will be about the same or even a bit larger.

Our corporate render farm is booked pretty solid 24/7/365 by the engineering/modeling/simulation group.

I'd like to set up a render farm of my own, but I'm not sure the computers we have would be worth it. Any help would be appreciated!
Current computer that KS is on runs 16 cores (Intel(R) Xeon(R) CPU E5-2630 v3 @ 2.40GHz) and 32 Gb RAM
We have 14-16 desktops sitting unused - Dell Optiplex 755's with  Intel Core 2 Duo E6550 Processor (2.33GHz, 4MB L2 cache, 1333MHz FSB, vPro, VT)

Would it make sense to run network rendering with all of these or would my desktop still be faster on its own? Is it worth it, or are they just too old/slow to make a large enough impact?

We're in a corporate setting, so going out and spending $2000-5000 on a new machine for rendering is mostly off the table.

Thanks in advance!