It could sound as if this was by some design. Of course you've already done the usual canned air cleaning, right?
On my laptop there are two air vents in the back. When I play videogames both vents blow hot air out and work perfectly. However when I am simply browsing the internet or not even on my comp, only the left fan runs and it is very loud. The right side (which fan isnt running) is noticeably hotter. What could be wrong with my comp? This has been going on for about two months and it really worries me because the laptop is only 1 year old