I don't know the names of the best fans like the experts here do. What I look for is the lowest dbs with highest airflow. If you have 100 cfm coming in, you should have the same or more coming out. This is neutral or -ive pressure airflow. With +ive airflow, air pressure is greater inside the case, trapping warmer air in the interior. Consider using nylons or some very porous foam as filters for dust/lint collection. Easy to clean and cheap to replace if need be. The nylons can go right over the fans, foam cut to fit in slots/spaces. Now you just need the experts to give you the name brands, but 16-20 db fans are pretty darn quiet, while 35 or higher can sound like you had better clear the runway for takeoff.


Edit: Additional fans such as Scythe S Flex or Gelid are 2 quality brands.