DON'T TRY THIS AT HOME!
I have unlimited access to PC components so I can pretty much do want and not have to pay for it. Given this I am incredibly cruel to PCs. You be surprised what you can get a way with. Here's what I've been doing for years, so far I've only lost one hard drive, that's all. I have a fanless cpu cooler and a fanless video card. The case and power supply cables have had the fans disconnected. I leave the side of the case off for ventilation. I have two large case fans connected to a switch, If I think it is getting too hot I turn the fans on. The HDDs are enclosed in sealed ABS cases. These get really hot and are under the most stress. I suspend the HDD inside the case to decouple them from the case.
So basically I have a completely silent machine. I use ghost to take regular disk images and I'm a backup freak. If it's worth doing then it's worth saving. If it's worth saving it's worth backing up. I've only lost one HDD so far and I simply replaced it and restored from the ghost image.
Like I said, don't try this at home, if you cook your gear then don't blame me!