I used to experience something similar on 737s, the controllers would agressively overcompensate with either freezing cold or uncomfortably hot air - could be fixed easily during the turnaround by releasing the grills from the cabin temperature sensors with a paper clip and then giving the foam filter a good shake!
€: On the 777 we recently encountered an improperly deactivated zone trim valve, it was left half open (when it should be deactivated closed), raising the temperature in the forward economy section to above 30 degrees... We couldn't do much except cycle the related trim air valve to keep the temperature within comfortable limits while keeping the other zones happy...
Last edited by STBYRUD; 5th May 2015 at 09:24.