I am the owner of Z3-710 with i5 CPU and Intel+nVidia graphics cards. Have to say very unhappy since found out neverending buzzing of fan is "normal". I don't think it is necessary to keep fan running on 1150 RPM even there absolutely no CPU or GPU performance. Also temperature is normal.
Having latest BIOS R01.A3 installed but there is no option to set fan speed to avoid unwanted noise. Have info from service that this noise is common even for other Z3 PCs. Really wonder if other users considering this noise as normal... For me it is very disturbing and pointless to listen fan. I have bought PC not beehive!
Believe the only one solution is to force Acer release BIOS update and reduce default RPM from 1150 to 800 or so. Thanks