Well hexdiy, I found the various Mac "fan controls" to be quite confusing some years ago when I really needed one for our hot running 2007 24" iMac, as most were meant for laptops and then I discovered the "Fan Control" I mentioned, and to confuse things, there were some others with the same name.
They are all from different developers and if one needs a more modern version there's Macs Fan Control
which I haven't used but the comments says it works well and with mavericks:
Macs Fan Control for Mac | MacUpdate
Macs Fan Control - control fans of any Mac & Boot Camp! | CRYSTALIDEA Software
Oddly I needed to use the Fan Control
with 10.6.8 on both our 24" late 2007 and 27" late 2011 iMac, but not when running 10.9.x on the 27" iMac. But I am using iStat Menus "Active Set" to boost the speed with 10.9.x on the 27" iMac but it doesn't always seem to do anything and needs to be reset often, especially after a restart or clean boot.
If one quits using a fan control pref pane, a SMC Reset should be done on the Mac to get the fans back to "normal", which is mentioned in their FAQ.