I have Early 2015 MacBook Air 13 macOS Seirra 10.12.6 Processor: 1.6 GHz Itel Core i5 4GB if Memore 1600 MHz DDR3 Graphics Intel HD Graphics 60000 1536MB I've done every known reset out there to fix this fan noise issue and my system app functions slows down too. I've tried the following. 1. SMC reset 2. Zap PRAM It will quiet the fan initially but you can hear it increase to full speed shortly after I reboot my MacBook. I sure don't want to take to Apple and spend a grand to get it fixed. That's what I've been quoted. I've exhausted Activity Monitor to see what has been eating up my memory to cause this overheating. There is nothing significant eating up memory. My next step is to uninstall Flash in Safari. Hopefully that will fix this. If there is anyone with suggestions please advise. That fan is driving me crazy!