Computers only work well in mild, stable-temperature environments. If the temperature swings wildly between daytime and evening (as it is apt to do in a garage), the computers will fail rather un-gracefully. I do not recommend that you keep them in the garage, attic, or anywhere that people would not be comfortable.

Perhaps my garage is unusual, it seems to keep a fairly stable temperature. I think it is helped by the fact that there are no windows and it is shaded from direct sun by trees or other buildings on all signs. I take you point about not putting computers where humans would not be confortable, but when I have been in my garage at different times of the day through out the year it has always been at a comfortable level.

I will be doing extensive monitoring of the temperature in their before I put anything important out there, though I may stick my own 386sx16 out there for a while as bait...

Instead, I would recommend doing what I do in my office: Keep things turned off that aren't specifically in use at that moment. Our print/file server and the attached printer only gets turned on when it's being used, for example.

That is really not an option in my case, the three hot and noisy items in my office are:

- my workstation (which I am often sat at for 18 or more hours a day)
- my email/dns/ftp/etc server
- my web /database/development server

They all need to be on I'm afraid.

As far as noise of running components, there are options for reducing the amount of noise made by your computer's power supply and fans:

This isn't any good for me. One machine is a Dell PowerEdge server with it's own special powersupply. The others are Dell desktops, which I would have to replace the motherboard on to get make use of the quiet power supplies (thanks to Dell's "nearly" atx power connectors).

I can cope with the noise, it's the 35+ temperatures in the summer that get me...