I heat my HOUSE by wood, which means we get a lot of dust inside ( & worse I e'spect!) I know you can buy metal enclosures to keep the dust out, but at $800/£400 a time I think maybe its not so difficult to build one........ so does anyone have experince of doing this? I'm a cabinet maker , also with some experience of metalwork so I, m not so concerned about how to construct an enclosure,more about how to size it? prapps there's some formula or rule-of thumb to do with how much heat can PASS through a certain amount of surface area??

Any thoughts on this subject welcome.

GeoffThe number one problem you will have enclosing a computer is simply the fact that you are not LETTING air exit.
You can make a cabinet out of wood and place a computer inside it if you wanted to, go to the store or look online at some enclosures and see how they allow air to exit.
If you can figure out a way to duplicate that affect, you could try it, but be sure to monitor the internal temperature of the computer using a program that can read CPU, Memory, GPU, and HDD temperatures, as well as the temperature inside the cabinet itself.

The ultimate solution would be to place the computer in a room where there is little to no dust.

We also heat a part of our house with wood, but have never had a dust problem. Are you using a wood furnace/stove or an open fireplace?
Yep its an airtight box stove, but there always seems to dust, maybe not only from the woodburner, and a very hairy dog who likes to spread it around (his hair, that is: Poor beggar got neutered before he came to live with us, so there's not much else to spread!)

Most of the commercial enclosures seem to go down the metal box + fan + filter road. I want to AVOID that because I'd like to cut down on noise (I do some music recording - try Sam Holman 'unborn' on youtube if you're curious; I'm the old guy mucking about with the mike stand). I thought that a metal box might act as enough of a heat sink to forget about the fans. Could even put some internal & external fins on it.

I thought I got notified when someone replied; better check on that.......You could attempt without the fans, but, get software for monitoring the internal temperature of your computer, like Speedfan http://www.almico.com/speedfan.php (I dont recommend you try any of the overclocking features... thats moreover for advanced users)

See what your computer runs at normally, and then see what it runs at in a cabinet.

The problem with a metal box is that, yes, it will act as a heat sync, but, if nothing cools the metal, then the metal will just sit conducing heat. Because of this, possibility of heating up over time might occur. Be sure to monitor it, checking it every so often. (Just in case)

Neat recording, its hard to find high quality recordings of people who dont belong to some overly popular famous band.

One of my personal favorites:
http://www.youtube.com/watch?v=vS0QjEeNYpM
I don't have any experience building my own enclosures. However, there are some companies that have products for this, e.g: http://www.dustshield.com/

You could examine some of their products to get ideas in building your own.

As Zylstra mentioned if you do build such an enclosure you need fans or some TYPE of method of drawing in cooler air into the box and then blowing the hot air out.

If you do happen to build one, we'd all like to see pictures when it's done.