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| Thread ID: 69041 | 2006-05-19 23:45:00 | Clean inside of computer with vacuum | technicianxp (6463) | Press F1 |
| Post ID | Timestamp | Content | User | ||
| 456248 | 2006-05-20 23:13:00 | SICK PUPPY I’ll try to answer the various questions that have been raised by my comments. An engineering designer for 50 years (3 continents) I have not myself ever modified my computer cases to have filtered air - my study is clean, and if it ain’t broke don’t fix it, is one of my sayings. No - computer cases don’t appear to have been designed for air flow in only one direction. The amount of air we are talking about is in any case pretty small. But if you use your computer in a factory making explosives (where I first heard of the modification) the last thing you want is to have the factory dust deposited all over your motherboard etc. I see computers in woodworking shops where the keyboards have been covered by those plastic things so that the keys remain clean. But the inside of the computers can often be hidden by a pile of dust. I remember once pointing out to a boss of mine the dangerous situation we had with an accumulation of sawdust. When we had the explosion and it blew out an end wall he believed me. Car filters do not use air travelling at the speed of the car. The air surrounding the filters is almost stationary- just like that in the car body. Of course the thing is more efficient without the filter but we are not concerned with that type of efficiency. It is of no consequence. SOMEBODY Yes a fan should operate as a dynamo - but 50 odd years ago I made numerous experiments with various fans spinning them with the vacume blower in an attempt to raise a voltage. I only had a cheap voltmeter in those days but I never managed to raise anything. However I apprciate the danger - I have never done any harm by my silly habit of spinning the darn things - but yes I suppose its possible. Try it at your own risk. But again “Don’t quote me” Your comment about heat rising is - well pretty pathetic (sorry about that) but the incredibly small amount of air movement caused by this is very tiny compared to the whacking great quantity of air moved around by the cheapest and smallest fans. Otherwise we would have convection cooled computers and fans would never have appeared. (what a wonderful thought). Tom |
Thomas01 (317) | ||
| 456249 | 2006-05-20 23:56:00 | For crying out loud,stop making this into a mission impossible movie. :D Use a clean small brush on the fans and anywhere there is heaps of fluff/dust/crap. Use 1/2 cans of compressed air in the case to get rid of the rest. Use a pencil to stop the fan blades spining so you can give them a good clean out.(if you want you can take the fans out and give them a wipe with a damp cloth and then let dry before puting them back). This should only take 5 min.,10 min. tops. Mission Impossible over!!! :D |
memphis (2869) | ||
| 456250 | 2006-05-21 01:10:00 | I take my PC's out to the garage once in a while and remove a side and lay it down . Then pick up my Garden vac set to reverse and blast it clean, they come out spotless . Also has the advantage of feeling like Arnold Schwarzenegger, there is a certain satisfaction in using a device looks like a big midi gun and pointing it at your PC . PS . vacuums (and garden vacs) in theory do build up a bit of static, compressed air is better although never had a problem . |
Battleneter (60) | ||
| 456251 | 2006-05-21 01:39:00 | Your comment about heat rising is - well pretty pathetic (sorry about that) but the incredibly small amount of air movement caused by this is very tiny compared to the whacking great quantity of air moved around by the cheapest and smallest fans. Otherwise we would have convection cooled computers and fans would never have appeared. (what a wonderful thought). Tom I will quote you because otherwise discussions get very confusing to figure out who said what in response to who, what, where, when why how etc. etc. While the volume of air movement is quite small, regardless of how much of an impact it has, why would you intentionally try to go against natural convection currents? The design of cases currently is to aid airflow, and heat dissipation by allowing the thermodynamic fact that heat rises, to help the fans by getting rid of heat via the fan in PSU. By forcing air to go in the opposite direction - ie. trying to push hot air down and then out, is wasting energy and effort. Furthermore, it does nothing to address the issue of less dust buildup, as the rear of PCs are usually very rarely vacuumed, and hence accumulate a lot of dust on the carpet/wall etc. |
somebody (208) | ||
| 456252 | 2006-05-21 02:13:00 | If you spin the fans up to high revs with a blast of air you will damage the bearings. FACT. | zqwerty (97) | ||
| 456253 | 2006-05-21 02:59:00 | While the volume of air movement is quite small, regardless of how much of an impact it has, why would you intentionally try to go against natural convection currents? The design of cases currently is to aid airflow, and heat dissipation by allowing the thermodynamic fact that heat rises, to help the fans by getting rid of heat via the fan in PSU. By forcing air to go in the opposite direction - ie. trying to push hot air down and then out, is wasting energy and effort. Furthermore, it does nothing to address the issue of less dust buildup, as the rear of PCs are usually very rarely vacuumed, and hence accumulate a lot of dust on the carpet/wall etc. Ah I think you have missed the point here. You might as well say why bother fitting a motor to a cycle calling it a motorcycle then having to carry all that extra weight around. And our very popular fan heaters - nobody ever has them turned up to the ceiling so that the natural air currents assist circulation. One of the first things I learned as an engineer is that there are umpteen ways of measuring efficiency and one must learn to differentiate between those that are important and those that do not matter. The real reason for having the fan drag in air at the back is for the sheer convenience of being able to fit the filter there - it would be a bit stupid putting it on the front. But again we do have to consider the fact that only the odd person has need of the air being cleaned. I don't need it - my computers internals are generally pretty dustfree free for several years (about time I checked that statement!), and I am a bit concerned by the remark that the backs of computers can be dusty. Not in my house or office mate. And on that point I do think people should check air outlets - I have found the occasional computer with the holes being almost blocked by dust. Not good. Tom |
Thomas01 (317) | ||
| 456254 | 2006-05-21 03:00:00 | Just to add to this the server which is the subject of my big clean-up sat has a very high-speed case fan plus a PSU fan at the back both blowing air out. It sat on a carpet for 1 or 2 years and the result was that the front intake which didn't have a fan in it eventually filled up with so much dust that there was no air getting through it (well so I presume). I guess the fact that there's only one HD in there (at present) explains why it's still running but I will have to get rid of the dust before I throw to more drives in. | technicianxp (6463) | ||
| 456255 | 2006-05-21 03:09:00 | If you spin the fans up to high revs with a blast of air you will damage the bearings. FACT. Naw! Never. I have done this so many times and been involved in test in engineering where high speeds were indulged in so as to find the limits of bearings and really its very hard to cause damage to bearing on things like fans. I have used sharp point "needle" bearings at times on low load appliances and many years ago used a formula to calculate the life of one of mine. I cannot remember the formula now - it wasn't my work but was accepted and in my case the bearing would certainly last for several hundred years. The best practical example I met with was in an electrical suppliers where the switch to the ceiling fan in the mens toilet had failed. Being electricians they just twisted the wires together - intending to do a proper job later. Ten years later the fan after running 24 hours/day continuously was still running as sweetly as the first day. But hey don't try this on bearing with reciprocating loads. Tom |
Thomas01 (317) | ||
| 456256 | 2006-05-21 03:37:00 | When cleaning fans, especially the smaller fans within a portable computer or laptop it's suggested that you either hold the fan or place something in-between the fan blades to prevent it from spinning. Spraying compressed air into a fan or cleaning a fan with a vacuum may cause damage to some fans. www.computerhope.com Air duster is quite useful for cleaning more robust items, but can also be usefully employed in computer destruction, where it is more than capable of blowing chips out of sockets, spinning fans to prodigious speeds and destroying their tiny brushless motor assemblies www.dansdata.com Also I have repaired many of these fans, even rewound them with various degrees of success, and replaced the transistors in them. The bearings are fragile and mounted in plastic housings they dry out, overheat, slow the revs down and burn out the motor. You must have come across some of them running at half speed? |
zqwerty (97) | ||
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