One easy and free way to eliminate the fan noise is that scenario is do uninstall Adobe’s power hungry Flash plugin. Another way is to use a nifty and affordable utility that controls fan speeds, and monitors the Mac’s temperatures.
Go Temp Gauge Pro
The Mac’s fan goes on for a reason and usually it has to do with an app that is sucking up plenty of the CPU’s power. Flash ads on webpages tend to do that.
If that happens to you from time to time, and the fan noise has become an irritant, then check out Temperature Gauge Pro.
Apple really should build in a similar utility because TGPro has just what you need to control the fans, and give you notifications when the Mac gets too hot.
TGPro displays the current and maximum recorded temperatures for each of the temperature sensors in your Mac.
Even better, it gives you an option to view and control the speeds for each fan. And, you can set up Auto Boost so the fans go to maximum when a specific temperature is reached.
One click gets you a look at temperatures throughout your Mac.
Even more impressive than the lengthy list of temperatures are the controls in TGPro. You’re given options to change temperature settings and fan speed, set Auto Boost temperature limit, adjust alert settings, and much more from the Preferences.
TGPro can display a notification pop up if a sensor in the Mac gets too hot. This is a good app to use to test the fans and sensors on your Mac (it includes built-in diagnostics).
It also logs and saves all temperatures, alerts, and fan speeds to a file which can be exported to a spreadsheet or database. Of the very few number of Mac apps which monitor temperature and manage fans, TGPro is the one I prefer.