The sound of (near) silence
The other day, my home desktop computer reminded me of Dave Lohbeck’s article “Design for dust.” Every summer when the outside temperature reached about 80, my home desktop PC would literally scream. A loud whining noise would build as the temperature rose. Even an air conditioner a few feet away didn’t help. When the temperature dropped, so did the loud noise.
When the temperature hit 55 this week (warm for January in New England), the whining noise returned. It sounded like a fan, but which one? This time, I wanted to find out. I opened the case’s side cover. The cover has an air vent directly over the CPU. Just inside the vent is a dust filter, held in place by an air concentrator (a funnel, really) that extends down to the CPU fan. The dust filter was dirty. I cleaned it and the noise returned to its “normal” level. Tolerable, but still a bit louder than it should be.
The following night I opened the case again and cleaned the inside of the case and the circuit boards with a hand vac and a rag. Then, I noticed that where was a layer of dust under the CPU fan, on top of the heat sink. I cleaned out most of the dust with a rag, then used the vac to remove the clumps that came out of the heat sink. What a difference. So quiet now.
The computer runs a bit faster. The dust was restricting air flow to the heat sink so now the CPU was running hot.
If you haven’t cleaned your PC lately, it’s time.
Martin Rowe commented:
I did a second, more thorough cleaning, removing the fans to clean around them. My PC is so quiet that I can hear the hard drive now.
Kurt commented:
Good advice. We stopping shipping some of our instrumentation chassis with filters since customers weren't replacing them. As the filters clogged, heat built up. Recommendations on cleaning are a good idea. If you have multiple computers or electronic products, make sure the exhaust fans don't blow on each other since that can cause problems as well.
