Its possible to configure fan activity from 70-90°c, like image below:

By default its configured to 75, and i´ve changed to 70. Until now, no problems. Temp is under 69°.
The fan is very silent. It´s very good!
My worry is about the fact to be a compact device, to be used on travels. I´m using in my house like my main router. Could it be a problem? I don´t think so… in my opinion! 
Tks