Here is the question- 

I can run browser based mining, such as bitcoinplus on around 15 pc's in my office. These computers are on 24/7/365 anyway. They are relatively older PC's, so they aren't terribly powerful, but, I look at it as free mining time. BTW- I have full permission to do this, if anyone is wondering.

My questions are; would it make more sense to install a mining program, and will either a browser based or a program based mining operation cause the PC's to use more electricity, and/or cause more wear and tear on the components?

What say the hivemind of BTC talk?

Thanks.