> The heat sources are the processor, the HDD and the DVB card > (more if it is a full-featured one). The noise sources are > the power supply (because this is the only one to the air out > of the case) and the heatsink on th processor. HDD is also a noise source. Proper rubber blocks can eliminate the noise conducted to the pc case and to your ear. > The bigger the fans, the better. The slower the fans, the > better. Thus try to fit 8cm fans with a resistance in series > to reduce speed (cf. > www.silentpcreview.com) There are fan controllers available at shops. They start fan with 12V/no modulation, to make them rotating for sure, and then slows RPM down with much better way than resistor. Electric motors can and should be guided with pulse width modulation (RC models uses this, try searching "rc electronic speed controller"). So on 12V, 1/12th modulation with 6 units on, fan's electric motor will see it as virtual 6V, but as real drive voltage is 12V, you'll get maximum torque out of your fan. And your fan rotates about half the maximum RPM. This is to make it simple, of course system isn't linear. With 6V your fan doesn't neccessarily rotate, at least not start. And motor will endure much longer, and fan motor heat is minimal. > > Finally, does anyone have any good ideas to minimise dust entry to the > > machine other than putting the machine inside a cabinet. Dust covers which are sold or shred a vacuum cleaner bag as a DIY project. > Minimize fan speed -> minimize heat generation -> underclock > the processor and take great care about the HDD you choose > (rule of thumb : > the lower the power requirements of the HDD, the lower the > heat + the lower the rotational speed of the HDD, the lower the heat) Choose 5400rpm disk, it can cope with multiple DVB-streams. Much less noise and heat. Many HDD's can be 'underclocked'. 7200rpm disks can made to perform like 5400rpm one. Check "hdparm -B" for APM support. Check "hdparm -M" for acoustic management support. Also HDD doesn't need to be running all the time, if your VDR is powered 24/7. Check noflushd for this. Works better than plain "hdparm -S".
