silence of the fans, making my HP/Tektronix lab gear a lot quieter

[Zucca]

If you look at graphs which show thermal impedance versus airflow you'll notice there is no linear relation between those. Without checking the actual heatsink specifications it is impossible to determine the new maximum temperature.

You got me, I was thinking about it while I was eating.
This is also what thinkfat tried to explain me.
Thanks guys.