I have got one of these for longer rides (https://www.topeak.com/global/en/pro...MTXTrunkBagDXP) but I am trying to avoid using it for daily commuting in that I would need to carry a backpack to transfer the stuff once I get to school.

I am not opposed to a new backpack, I just don't like my back getting all sweaty with the one I currently ride with. Any suggestions on packs with minimal sweat factor?