If you want practical advice here it is:
1) Firstly the nouveau FAQ which includes the question
[http://nouveau.freedesktop.org/wiki/FAQ#The_fan_is_really_LOUD_all_the_time._How_do_I_make_it_more_quiet.3F
"2.16. The fan is really LOUD all the time. How do I make it more quiet?"]
and the answer:
On many cards, the fan is temperature controlled already, but obviously in
your case it is stuck at the maximum speed. We need some help from you to fix
it, but we do not know yet what you could do for us, exactly. Please, check
this FAQ item every once in a while, we will tell you here what to do, when
we figure it out. In the mean time, if you are interested, you can read
PowerManagement and/or contact mupuf on the #nouveau freenode IRC channel.
Your help is needed to fix this issue.
2) Replace the graphics card or fan. I know you said you are short on funds
but maybe you could find a second hand one from a friend that is passively
cooled or uses a lower power fan and they are not using.
3) Freedom 1 allows you to download the source code and hack on the nouveau
yourself or hire someone to do so.
But basically if the upstream nouveau developers have not fixed the fan
problem it is even more unlikely someone from Trisquel will be able to
because our knowledge of the source code will be worse then those of the
nouveau devs. I would join the #nouveau irc channel and try to help them
out.
