The fans run permanently. However, they idle around 2000 RPM. How much better is the new account? Is the computer running normally? If so, then there is a problem in your user account. Consider doing this:
Repair the Hard Drive and Permissions if you have not already done so. See the following excerpts from my maintenance FAQ. Cache cleaning as well as cleaning temporary files and log files.
Four outstanding sources of information on Mac maintenance are:
1. OS X Maintenance - MacAttorney.
2. Mac maintenance Quick Assist
3. Maintaining Mac OS X
4. Mac Maintenance Guide
Cache Clearing
I recommend downloading a utility such as TinkerTool System, OnyX 2.4.3, Mountain Lion Cache Cleaner 7.0.9, Maintenance 1.6.8, or Cocktail 5.1.1 that you can use for periodic maintenance such as removing old log files and archives, clearing caches, etc. Corrupted cache files can cause slowness, kernel panics, and other issues. Although this is not a frequent nor a recurring problem, when it does happen there are tools such as those above to fix the problem.
Other Suggestions
Be sure you have an adequate amount of RAM installed for the number of applications you run concurrently. Be sure you leave a minimum of 10% of the hard drive's capacity or 20 GBs, whichever is greater, as free space. Avoid installing utilities that rely on Haxies, SIMBL, or that alter the OS appearance, add features you will rarely if ever need, etc. The more extras you install the greater the probability of having problems. If you install software be sure you know how to uninstall it. Avoid installing multiple new software at the same time. Install one at a time and use it for a while to be sure it's compatible.
Additional reading may be found in:
1. Mac OS X speed FAQ
2. Speeding up Macs
3. Macintosh OS X Routine Maintenance
4. Essential Mac Maintenance: Get set up
5. Essential Mac Maintenance: Rev up your routines
6. Five Mac maintenance myths
7. How to Speed up Macs
8. Myths of required versus not required maintenance for Mac OS X
Referenced software can be found at CNet Downloads or MacUpdate.