help power wi-fi power drain settings on iphone

Hello,
I have had my iphone for about a year now. It is the iphone 4. It has never been used as a phone; only as a device to connect to the internet (no phone carrier and mobile wifi signals). I use it at home or wherever I can find free wi-fi.

At work, I just was given the wifi password for the first time and connected to the network. Now though, my iphone is always dead before my 8 hour shift ends...but at home, it seems to stay connected to my home wifi for days without recharge.

It is only when I bring the phone to work now that it will take all of the power. I'm not sure what it is doing, but figured I just have a setting wrong or something?

thanks,
Micah

Seeing no responses to your question I thought I'd just throw this in:

Your work router/software is probably demanding constant info from your phone and or your phone is having to constantly search for the system.