Is Your Computer a Fire Hazard Waiting to Happen?

whoppers asks: "I'm sure we've all had our share of computer fans die, but what happens if your box is running while you're at work and several fans go out? My in-laws spare TigerPC AMD K62-400's power supply fan just went out about two hours ago, and the thing was blazing hot. A little poke to the blade, and it started up again, but shouldn't these things be made to stop if the fan stops for any reason? I'm starting to wonder if I should start leaving my box off when I'm away for a few hours. Since it's usually wide open, I don't see too much harm, but these cheap boxes that never get opened and cleaned have to be a hazard right? I can't afford a halon system in my office just yet. The only link I found related to this is here and should a few more people read this, here's the cached version. Does anyone have any thoughts or stories related to this?" The fact that this article appears on July 4th, when most Americans will be lighting fireworks is purely coincidental. That doesn't change the fact that the submittor raises a very good point. A general rule of computers is: the older they get, the more dusty they are and dust bunnies and their denser cousins are highly flammable. Unless you can keep such machines clean, it' is probably safer to leave them off.

Comments

Hmmm

[shr3k]

The only link I found related to this is here and should a few more people read this, here's the cached version.

A link to the cached version? Come on, this is Slashdot. What's the worst that could happen?

So what???

[josh crawley]

Yeah, old comps do get dusty inside. However, even if the fan quits, it's still not a problem. That bit of dust is flammible, but the metal aint. There's a fireproof box around those bunnies. ANd once it smolders some, it'll burn out most of the O2 (since the fans dont pump air cause of dust). There goes your "fire hazard"

The only thing is it's a boring news day.

Re:So what???

[Beliskner]

ARGH!! Another problem that can be solved with a component costing 10 cents - a thermal fuse. All you software engineers trying to read hardware interrupts from fan speeds and temperature sensors. What if the FAN_SENSE wire shorts with the PSU's AC output - even if the fan stops working it'll still look like it's giving 60rpm. Leave this to the electrical engineers now go back to Java or VB software peopl.

ASUS

[selderrr]

the new ASUS motherboads have COP : CPU Overheating Protection, which switches off the machine when temp goes baloony.

And they're damd fine MoBo's too...

Re: ASUS

[Black Parrot]

> the new ASUS motherboads have COP : CPU Overheating Protection, which switches off the machine when temp goes baloony.

I have an ASUS board a bit over a year old. I do intensive number crunching on my home machines, with some jobs running over a week of continual 100% CPU time. Being AMDs, they tend to run kind of hot, too, so sometimes I put a room fan blowing along the wall behind the boxes' exhausts.

At any rate, one warm day I had the A/C set kind of high and the room fan aimed elsewhere, and one of the boxes overheated while I was out to lunch. But the board halted it for me. When I came home it was making a horrible alarm sound, and unfortunately I had to reboot because I couldn't figure out how to make it restart after the alarm, but at least I didn't get a fire, nor even any overheat damage to the CPU.

BTW, Linuxers/BSDers who have temperature sensors on their motherboards may want to run lm_sensors and a display such as gkrellm in order to keep an eye on your system temperatures when you are around.

If your power supply is UL/CSA approved

[shepd]

You have nothing to worry about. They test for things like the fan stopping.

Eventually, when the heat gets too high, the power supply will either shut off or destroy itself.

The UL/CSA logo (if its genuine -- many cheap power supplies don't put on genuine labels) "guarantees" the power supply won't be dangerous to you. A flaming power supply would be, obviously.

Hope that allys your fears!

Re:If your power supply is UL/CSA approved

[tzanger]

Destroy itself? Hopefully it wouldn't destroy itself in a firey ball of flame...

that is one of the things that UL certified equipment is tested for, numbnuts.

Basically they put cotton "fleece" around all the openings and cause a catastrophic fault. If any of the cotton burns, you fail.

With our power electronics equipment, the fault consisted of shorting out the load side of our equipment while we were connected to a bus capable of delivering 100kA. We passed just fine, but it was the fuses which afforded us that protection. Remove the fuses and the results are ... well... spectacular.

monitor fire hazard

[eagl]

At work they made a policy that ALL computers will be completely shut down at night after a monitor caught fire one night and burned out an office. Normal hardware shouldn't catch fire even when old/crusty but there's NO guarantees when the hardware is defective to start with.

My CPU Fan is on my Left. My CPU, on my right.

[Anaplexian]

If I had a webcam, I'd post a link to a photo.

I'm running Win 98 on a Cyrix M2 233MHz overclocked to 300MHz (came when I bought it).

I paid 2500 rupees for the processor, [ 1 US$ = 48 Rupees - do your math], and thus don't really care much about it. :)

Anyway, it's 40 degrees here in Delhi, I don't have an AC, and my CPU Fan's bust for *over a week*. And it's happened several times before.

What do I do? I take off the Hood, Put my ceiling fan to "Maximum" and keep on Photoshopping.

I'm a comp Sc student, and I know what I'm doing is insane.

but, Hey, As long as it's running, Who cares?

Always open?

[Amarok.Org]

Since it's usually wide open, I don't see too much harm, but these cheap boxes that never get opened and cleaned have to be a hazard right?

It should be noted than a open computer case will likely run hotter than one properly closed up.

Fans are designed to move air - like any fluid motion, air will move along the path of least resistance. In the case of a case fan, where the case is left open, you're pulling air from a very small area right in front of the fan before exhausting it out the back. The heat generating components (CPUs, hard drives, video chips, etc) tend to be far enough away from these fans that you'll see almost 0 airflow over them.

I used to work for a major hard drive manufacturer, and would get complains from users who said our drives were running too hot. Quite often, they said "I even leave the case off, and it's still too hot!". Many times, just putting the case on solved their heat problems. By creating essentially a duct for the air to flow through, the fan was able to pull air from the front of the case, across the heat generating components, and then exhaust it out the back.

In the case of components with their own fans (CPUs, video chips), this is still important - while you've exhausted the hot air from around the component, without a properly functioning (read: case on) case cooling system, that hot air is never removed from the general area around the component, and just gets sucked back in on the intake side of the fan.

Just my $.02.

A good point though

[dalassa]

Even if the computer never over heats dust and oils and other icks can still kill a computer. I once was trying to fix a women's computer that had stopped. I opened up the case and the entire motherboard was covered in oil and fur. Turned out she let her cat sleep on it all the time and never cleaned it. All that direct exposure to animal bits just killed it. She had to buy a new computer.

I now religiously check the dust levels of my computers.

Danger with Old PCs

[shr3k]

My friend has an old IBM PS/1 that's a 486 with a Pentium Overdrive chip that he uses as a print server. While he's been away, I've had to fix the machine. It was scorching hot to the touch and I thought the power supply was going bad.

After considerable effort, I removed the power supply with the intention of replacing it with another AT one that I found. Unfortunately, the power supply had extra proprietary connectors and the replacement one didn't, so I was left to figure how to fix the original one.

I took a closer look and I saw nine (9) years (!) worth of dust clogging the power supply fan, thus blocking its motion. Ignoring printed warnings as "Caution! Shock Hazard" and "Warning: No User Serviceable parts inside", I carefully opened the power supply and removed the fan. Fortunately, the fan had a plaster connector for easy plugging/unplugging (as opposed to being soldered directly to the board).

So I removed the fan with easy and scraped (yes, SCRAPED!) the crap off of it and wiped it down. Then I applied WD-40 to the bearings to get the fan blade with more ease. I had to help the WD-40 spread by using a screwdriver to turn the fan both directions. Finally, after 20 minutes of effort, the fan blade was turning reasonably well with I'd tap it, so I put it back in, reconnected it, and reassembled the power supply.

Once the computer was put back together, I turned it on and felt for heat. Not alot. For the first time in a while, there was ventilation coming from the back of the power supply and the system was running much cooler than before.

So, let this be a lesson to you. Make sure you regularly (yearly?) clean your fans off, removing the dust before it cakes on. Make sure that you do this to any older PCs you have or are about to obtain.

Otherwise, your system will run dangerously hot and only bad things can come of that.

Re:Danger with Old PCs

[JabberWokky]

Good thing wd-40 ISN'T a lubricant. It's a cleaner. after using this apply the real lubricant.

You're both wrong. It's a water displacement formula. Specifically, it's Water Displacement formula number 40. It's very good for many applications, especially dealing with and protecting metal parts subject to rusting.

Functionally, it works as a lubricant fairly nicely. Also as a cleaner. It also kills ants, and, with a lighter held in front of it, is a fun party tool. It may not be the best at any of these, but it functions pretty well as a general purpose tool - I keep a small can in my toolbox, and usually have a large one around. For parties.

--
Evan

Dust filters

[scott1853]

How come nobody has made a case with an air filter on it so you only have to brush off the filter every month instead of taking a can of air to the box?

Re:Dust filters

[dattaway]

I have a little story about air filters and overheating...

At work, one of the PM guys wanted to protect all the large, expensive DC motors on the manufacturing lines with an air filter on the blower motors. Well, next thing we know, there's filter fabric zip-tied to every blower opening on every motor.

The fabric didn't restrict the air flow too much. Until a week later, when the grease and dust in the air clogged them up. Then the problems really started showing up. If you look up the prices of DC motors in supply cataloges, you may notice the prices run up to $100,000 each for the large 500 horsepower models. It seems our desire to protect these babies created an intense smell of burned enamel. When you have about 300 of these motors laying around, many in obscure places, we learned its better to have dust caked up inside the motor than have an undersized filter trying to protect it.

So, the question is, are you going to change or clean this filter on a regular basis?

Re:Simple Solutions.

[rehannan]

Use an air compressor on your computer if you want a fine mist of water sprayed over all your expensive electronics. Air compressors have drain plugs for a reason!

Your much better off just buying cans of "compressed air" (it's actually not air per se).

Poll

[Kingpin]

Instead of chasing windmills, let's have a poll on this.

Spontaneous computer combustion:

( ) Seen it
( ) Heard of it
( ) Heard of someone who heard of someone who...
( ) Nope

My point is, is this really an issue to worry about?

Re:Poll

[Technician]

Having dealt with several failed fans in the history of being a service technician, I must say I have never seen a fire related to a fan failure. Most of the time people bring them in because of a smell and before anything shorts out. I replaced the fan and the warranty is void sticker with our shops and send it home. (now supplies are cheap so we just replace the supply except for the hard to get proprotiory junk)
Most smoke issues seen have been:
Ruptured filter capacitors. They have a steam rupture due to the electrolytic. (the end blowes out some times ejecting the roll of tin foil) Boiling water is not hot enough for any flames and the spacer is still wet and won't catch fire.
Shorted power transistors. These may smoke the case of the transistor or take out some flameproof resistors before taking out the main fuse, but again no flames. Shorted disk ceramic or tantilium capitors. These are not made of flamable materials. Last is Metal Oxide Varistors (surge protectors). These tend to smoke the covering, but the part itself is made of non-flamable materials.
In monitors, shorted high voltage supply transformer and the degausing thermistor The transformers really stink with a burning plastic and tar oder, but they are built with self extinguishing materials. The thermistors smoke the plastic covering, but the part itself is not flamable. Again, never had seen a flame continue burning after the fuse or regulated power supply removed the power.
In summary, unless you get enough combustible lint near a severely overheated part, the risk of fire is very low.
The only fire issues I have ever heard about were caused by some defective battery packs for a laptop. There was a massive recall for the batteries. I certanly wouldn't a flaming laptop in my lap. I may want children someday.

How to set fire to your computer.

[Target Drone]

The illustrated guide to breaking your computer shows you the correct and incorrect way to light your computer on fire.

only if it's a well-ventilated case

[Trepidity]

Which a great deal of them aren't. With most of the computers I've owned, if I took the side panel of the case off, the CPU ran a full 8-10 degrees C cooler than with the case fully closed. This is primarily because the poor case cooling meant that the air inside the case was 10 C or so hotter than room temperature, so removing the side panel let the CPU fan suck in cooler outside air to blow on the heatsink (since the CPU fan is at 90 degrees to the motherboard, it's good at sucking air directly from outside if the side panel of the case is off).

Re:not so

[pete-classic]

Yeah, except you have to reach a temperature at which the plastic will create a self-sustaining fire for this to happen. What temperature do you think butane burns at? Ever tried to burn plastic with a lighter? Ever tried to burn paper with a naked CPU?

The whole question hinged on wether a CPU or PS will reach a high enough temperature to raise nearby combustibles to /their/ burning temperature. I think that the clear answer is "no."

-Peter

Using the wrong computers?

[gerardrj]

Perhaps if this has become a fear for you, then you should visit Apple. All of my mac systems to date run very cool. I've intentionally shut down the fans (usually one, not more than two in a case) and run the computers for hours without any significant heat build up.

The PPC runs much cooler than its x86 cousins. Mac cases also tend to be built with convection cooling in mind with vents on back and sides unlike most solid metal cases sold for use as x86 machines. The inside of my G3 didn't start running at all warm until I installed a VooDoo5/5500 card (that thing pumps out some heat).

I'm not looking to start a war here, but this is simply just one aspect of the Mac that most people seem to like: the cases. Many articles and revires pine over the Mac's enclosures, wishing some generic case vendor would attempt something like that for the modders on the x86 side.

Re:Using the wrong computers?

[iankerickson]

You've never owned a 6400 or a 6500 then. The CPU/PS fans are so weak, the Mac tends to lock up on hotter days. If you look on google, you can find entire web sites devoted to publicising the problems with these machines. They were cheap, but IMHO not worth the trouble.

And the 6400/6500 case is anything but "easy to open". You need a special tool (a case splitter) -- otherwise you have to nearly rip the calluses off your fingertips (after your fingernails go first) straining to pull the front off. When you hear the sudden, loud CRACK sound, loud enough to suspect you broke something, then you've got the front off.

Like a lot of pre-Steve macs, the fasteners are all made of plastic or very weak metal, so unless you go carefully, you can easily break a Mac case where it will never close again properly. The PowerPC cases are great examples of the this. Everything, from the card guides for the NuBus cards to the tabs that hold the motherboard in place are made of very fragile plastic. If you're ever working inside a Mac made from about 94 to 99, be careful!

Macs have this ridiculously undeserved reputation for having great cases that are easy to work with and won't cut you. This is pure hype. The aluminum flashing inside a Mac case as RF shielding tends to get bent up as you open and close the case and is hard to straighten. I've been working inside some PowerMac and said to myself "Hey, what's that little maroon bead on the motherboard..." before I realised I was bleeding. On the upside, the shielding is sharp enough to make a clean cut.

SOME macs do have good cases, but most do not. Most require special tools (like torx wrenches) and a reasonable understanding of electronics, especially the Macs with built-in monitors (like not electrocuting yourself on the CRT). The recent macs once Jobs was back at the helm have much, much better cases than almost every mac that Apple ever made. If you have basic PC building skills, than a post-iMac era Apple machine should make you feel right at home. For all the earlier ones, read up on the specific model before you do anything. They're no worse to work on than cheap clone PCs, but they have their own unique gotchas that are sometimes so wierd, proprietary, and/or dumb, it's best just not to guess.

Apple kind of runs under this idea that the computer they are selling you is actually an _appliance_, which should run reliably as designed (not that it will). But if it doesn't, you're expected to "take it to the dealer" and have them fix it, like a car or television (which nobody does, because you'll get ripped off or have to bring it back multiple times). That's the only way they're managerie of case designs make any sense, is if a trained Apple Service tech is the only one whose ever supposed to open it.

I wouldn't buy any mac unless I already had the directions on how to open it up and work inside. That will give you an idea how many proprietary plastic parts you might have to buy from Apple for $10-$40 each if you muck around inside. If they're still available. That's what I advise people who ask me advice about what mac they should get, especially for people buying used macs.

Re:Fire insurance discounts?

[Sircus]

Maybe insurance companies should offer discounts to those of us with common sense enough to buy and configure motherboards that have a "Power Off on High Temperature" option in the BIOS.

The fact that they don't is probably sufficient indicator that the incidence of overheating motherboards burning people's houses down is very low indeed.

Mac OS does this

[vought]

Mac OS X will terminate on an overheat signal. On the new XServe, the machine can be configured to send an alarm or shut down upon fan failure.

But I guess you get what you pay for, since Macs can be significantly more expensive.

How easy would it be to integrate that sort of thing into all the flavors of Windows or into Linux?

There are controller cards that do this

[gelfling]

I've seen Watchdog cards used for this purpose. When the temp rises above X deg. it performs an orderly shutdown. I believe there are IBM desktops and servers that have this feature built in.

fan speed sensing

[frovingslosh]

Many, if not all, newer motherboards have temperature sensing (a must for the Athlon chip). Some even have extra inputs available if you want to add extra temperature sensors.

Perhaps more applicable in this case is that these boards also offer inputs for fan speed sensing when used with an appropriate fan (generally the ones with 3 wires and a small tach sensor built in). Unfortunately, I have yet to see a power supply that comes with such a fan and provides the sensor feedback to go back to the motherboard. (I'm not saying they don't make them, just in my limited experience I haven't seen any.) If you could find the right size fan with the speed sensor you should be able to install it in the power supply and route it to the MB though. If there was enough demand voiced I expect the sensor would start showing up, but manufacturers would have to know that some people we basing case purchases on this feature.

This doesn't help older systems like this Tiger system much, but the issue has been addressed. There also have been available for quite some time temperature sensors that you installed in the case and they would sound an alarm when a critical temperature was reached. Several years ago I had a programmer build some watchdog timers for some critical systems with PIC chips and we decided to add a Dallas temperature sensor. By tapping on the reset button a few times you could get it to beep the internal case temperature back to you.(Obviously, you didn't reset the computer - the watchdog took over the MB reset input so it could reboot the system if it detected a failure. A long press of the reset could still reset the system through the PIC chip.)

This is reasonably timely for me, just yesterday I started getting alarms that my CPU fan was erratically slowing down. So far CPU temp looks good, but I'm going to have to replace the fan (if I can find an available fan of the right size with a speed sensor) or the whole heat sink assembly. I do have another 12 volt fan with the right hole pattern, but it lacks the speed sensor and is much thicker. Maybe I could find some really long metal screws and stack both fans above the heat sink, count on the new one to cool the CPU, but the old one to help and to continue to monitor the RPM and airflow. Any thoughts?

Re:Actually, yes

[CrystalFalcon]

Link.

Yes, specced clock and voltage, and then heat sink shot (removed) to see what happened. The overheating ones were AMD procs; Pentiums did not (I say again, DID NOT) overheat anywhere near these temperatures.

I don't remember the ignition temp for your average plastic, but I do remember (from office fire safety training) that paper tended to have the lowest ignition temp of everyday materials, closely followed by wood. My associations to burning plastic are more along the lines of "toxic as hell so get out", I don't remember a specific temperature.

Re:Actually, yes

[Papineau]

Ignition temperature for paper is 451 deg Farenheit, hence the title of the book. For the rest of the world, that's 233 deg Celsius. Still lower than what a bare CPU can reach.

Forgot a choice

[Peale]

( ) Coyboy Neal poured gasoline on it

P4 does it well

[txgaia]

Toms Hardware did a test where the heat sink was removed from 4 kinds of processors while they where in heavy use. The P4 stepped down the speed until it managed a safe temp. The P3 halted and the two types of Athlons incinerated. (It hit 698 degrees almost instantly once the heat sink was removed.) Maybe the P4 is worth the extra cash. http://www.tomshardware.com/cpu/01q3/010917/index. html

Re:Actually, yes

[CrystalFalcon]

I wasn't saying there was danger, that would be interpreting the numbers you asked for. If you want to go hunting for fire hazards, my first three steps would be installing a smoke detector, a fire extinguisher, and reviewing the home insurance policy.

Actually, the fire safety training I mentioned was quite amusing in that regard. The fire officer leading the training asked for a show of hands how many had smoke detectors in their house; almost everybody had. His follow-up question was how many had fire extinguishers. Almost nobody.

"Oh, excellent!" he said. "So, you wake up in the middle of the night from the smoke alarm you've installed. You know there's a fire in your house. However, you have no extinguisher! So now you do... what?" :-)

don't run your computer open

[g4dget]

Since [my computer] usually wide open, I don't see too much harm, but these cheap boxes that never get opened and cleaned have to be a hazard right?

Computers are not designed or approved to be run open. It's a stupid thing to do if you are afraid of fire--they get less air circulation, they run hotter, and if they catch fire, the fire can more easily spread. Running your computer open also violates FCC rules because it will cause lots of interference, affecting radio operators, police and fire communications, baby monitors, and medical equipment.

Computers are designed with metal cases for good reasons: they allow the fans to work, they conduct heat, they keep RF inside, and they offer some protection against fire. Don't run your computer open--it's just stupid.

Thermal monitering software

[Yottabyte84]

Under both Windows (Motherboard Moniter) and linux (lm_sensors) software exisits that can moniter the built in thermal and fan sensors that most modern motherboards have, and can be configured to shut down your computer when it overheats or a fan fails.

Re:Actually, yes

[ColaMan]

It's not just about your CPU failing.
If you have a serious PSU failure there is a good chance you'll have insulation breakdown on the 110V(or 240V in my case) mains section.If this breakdown happens *before* the fuse (which is generally located on the board) , you can have the situation where you can very easily reach temperatures high enough to start a fire in most things.

If you are not careful about your house wiring, or power your system(s) with cheap, thin conductor extension leads/power boards,you can go for some length of time (30 seconds or so), before the fuse blows or the breaker trips. Not good if your power supply has just turned into a 1000W bar heater.

Honkey Crap

[tarsi210]

This system administrator woman is full of honkey crap in so many ways. I urge people to leave their machines on for the following reasons:

1. Most modern systems are made to "sleep" when you're not using them. If your monitor is set to power off, your hard drive to spin down, you'll be fine. Power consumption at a low, automatically.
2. Every hard drive that I've seen fail sans one or two have failed when the machine got turned OFF. The next time you turn it on...nothing. Rarely have I seen a harddrive fail while the machine is powered up.
3. The power surge that flows across the motherboard at powerup, not to say anything about the repeated heat-cool-heat-cool that the chips go through as you power on and off each day cannot be good for them.
4. Dust does accumulate, but not THAT fast. I just powered down a 279 day uptime server and the dust was there, time for a cleaning, but nothing significant. (2 fans - 1 PSU and 1 CPU)
5. Security by shutting computers off isn't security, I don't care who you say you are. Educate your users.

I lay my case down for better cooling...

[FyRE666]

I've found that just laying my case down lowers the temp (only by 1-2degs to be honest). I figure this is due to the fact the CPU will be facing upward and so the heatsink is working more efficiently.

I've also found that adding a fan to the top of the case to pull the hot air out (on upright cases) makes a BIG difference, especially on smaller cases designed for the MATX boards. I had an athlon in a small case that was running at 60-65degs and very unstable until I cut a hole and put a fan in the top - it dropped the temp to 50-55degs and hasn't crashed since.

I think the biggest single difference I've made was adding a Coolermaster "Heatpipe" heatsink to an Athlon - that thing knocked 15 degrees off the CPU temp immediately! I had to remove it again though, as the noise was unbearable... It makes a nice-looking paperweight though!
Also little things like tidying up a rats-nest of wiring and putting dummy plates over unused expansion slot cut-outs in the case helps.

*DON'T* Use WD-40 on small moving parts (ie. fans)

[BigBlockMopar]

Functionally, it works as a lubricant fairly nicely. Also as a cleaner. It also kills ants, and, with a lighter held in front of it, is a fun party tool. It may not be the best at any of these, but it functions pretty well as a general purpose tool - I keep a small can in my toolbox, and usually have a large one around. For parties.

I agree with everything you've said except for *one* thing.

Don't use WD-40 as a lubricant. Use it as a penetrating oil, to free stuck and seized moving parts. But once they're unstuck, clean them thoroughly with carb cleaner or something similar, and then use a proper oil or grease to lubricate them.

Speaking from experience, WD-40 turns sticky with time. Small machines (ie. computer fans) will seize.

If you *have* to lubricate a disassembled computer fan, use ONE drop of the lightest machine oil you can find - the smallest SAE viscosity number.

However, dust in the air passing through the fan will magically be attracted to the bearings and trapped in the oil, where it will eventually seize the fan again.

Good computer fans have graphite-impregnated sleeve bearings. When the bearing ceases to be self-lubricating, the bearing is worn out and it's time to replace the fan.

Cheap computer fans (and those sold to people who don't know any better) use tiny little ball bearing assemblies. With outside bearing diameters of less than 1/8" in some cases, the balls are absolutely tiny, especially relative to any dust which might become trapped in them. The "ball bearing" fans are especially prone to failure, and should also be avoided, unless you're buying expensive ball-bearing fans for use in your clean room.

Replace the fans. If you have to take them apart to clean/lube them, they're finished, and will fail again soon.

www.papstplc.com

and, manufacturer of the legendary Muffin Fan used everywhere from Cray computers to the Space Shuttle,

www.comairrotron.com

I don't believe in repairing cooling fans, and I don't believe in the cheap crap which washes ashore from Taiwan and infiltrates our computer cases.

Buy good fans. They'll outlast your computers, and you'll never need to do more than vacuum them.