It's cool man ... ;-}
No, the fan specs is not overly different. What is different is the CPU. Haswell chips just run cooler so the need for more cooling is not required.
As to the older units you may want to look at what you are running on your system. Some older stuff have issues with poor code & thread management (i.e. Flash). Once we upgraded Flash as an example to the newer 64bit version we did see huge improvements in running video not causing the system to heat up as much.
You may want to check out your system for dust buildup (logic board, fans & heat transfer fins) and if the thermo paste is degraded.
We're very hard on our systems (CAD) and we don't have heat management issues in general on our Air's. True the fans do come on at full speed at times but thats to be expected (not sustained).