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Putting my PC's in the attic
Temperature related concerns
trillianjedi




msg:388497
 11:25 am on Aug 4, 2004 (gmt 0)

I have 4 PC's running at home on a LAN which I do need (4 different OS's) for development purposes.

I want to get the lot out off the dining room floor and into the attic.

I know it gets damn hot up there. I went up last night and measured it at 30 degrees C.

It has been really hot in the UK these last couple of days, but it's a regular occurance at least once a year. It's nice and cool in winter. Doesn't get damp.

Am I likely to run into problems with the PC's up there? There is air circulation, but generally hot air doing the circulating!

Anyone here run PC's at extreme temperatures and got away with it?

Thanks,

TJ

 

dwilson




msg:388498
 11:32 am on Aug 4, 2004 (gmt 0)

My experience w/ running server PC's in a room that was too hot was that we had a lot of disk drive failure. Admittedly, those systems did a lot of disk access, but the failure rate was higher than one would expect, so we attributed it to the hot room ... approaching 90 degrees F. (that would be ... 90-32 = 58 * 5 = 290 / 9 = 32 C.)

trillianjedi




msg:388499
 11:39 am on Aug 4, 2004 (gmt 0)

Hmmmm.... yes - that does worry me a bit. One of the machines is running as an FTP server - fair amount of disk access.

I don't want to go to the expense of air con, although I might look into watercooling, if I could somehow just plumb it up to the mains water supply rather than using pumps....

Did you try those drive cooling devices?

TJ

dwilson




msg:388500
 11:45 am on Aug 4, 2004 (gmt 0)

No, I didn't try a water cooler. We had about a dozen systems in that room, so we just tried to get the building's AC to take care of it, but it didn't do too well. Eventually moved to a different facility.

The only systems that experienced the problem were the heavily-used DB servers ... so disk access was definitely a factor. Still, the heat seemed to be as well.

trillianjedi




msg:388501
 11:48 am on Aug 4, 2004 (gmt 0)

OK, thanks. Might need to have a bit of a think and a google around.

Water is the obvious solution for me, but it's going to be a whole load of hassle.

TJ

Reflect




msg:388502
 1:45 pm on Aug 4, 2004 (gmt 0)

For the price of geting water coolers in the workstations why not have a "handy man" install a ceiling/attic vent fan? Basically it just is a set of vents cut into the roof and a fan hooked up to them. I use this in our converted attic. It has AC and a cold air return duck but heat built up any ways. The fan brought it all under control.

Take care,

Brian

raywood




msg:388503
 1:48 pm on Aug 4, 2004 (gmt 0)

trillianjedi,
I was a hardware designer for many years, and also did some time as a reliability engineer. My advice is don't put your computers in the attic. Temperature and MTBF are inversely related, and you will dramatically reduce the MTBF and life of your machines.

ogletree




msg:388504
 1:56 pm on Aug 4, 2004 (gmt 0)

I saw some AC's on the net for as low as $339. You could build a box the size of the AC and computers and ventalate it right and also ad some insulation. That should save you some money on the electric bill. The whole thing should not cost more than $500. It may be the size of a desk.

trillianjedi




msg:388505
 2:01 pm on Aug 4, 2004 (gmt 0)

Thanks guys. And thanks for the fan vent tip - I may look into that. There is actually already an existing roof vent from when I moved the bathroom and had a new vent put in on the other side of the roof.

It's been blocked off with a cap, but I'm sure could be made serviceable again. It's about 15cm in diameter.

My advice is don't put your computers in the attic.

Assuming I don't have a choice, and I need to lower the temperature of the location rather than change the location, are there any other options?

MTBF = Maximum Time Before Failure or something similar?

I saw some AC's on the net for as low as $339.

I already own two of those ;-)

Yes, they're great for the money, and I've thought about getting another one for the attic, but the consumer household ones are really not designed to be run 24/7.

Thanks,

TJ

jim_w




msg:388506
 2:14 pm on Aug 4, 2004 (gmt 0)

trillianjedi

raywood is correct. I use to run ALT, (accelerated life test) on ICís for Motorola. Itís not the microP you have to worry about. Itís the power supply.

I had a fan go out in a computer and the thing over heated. It wasnít the Ďcomputerí that over heated, it was the power supply. I know this because I have a fan card to help in the main cavity of the box stay cool. I replaced the fan and the system started working again, but, if I let the temp go over about 73F, the power supply starts to fail. I can hear the fanís speed changing. I believe it is due to a cap leaking because of the heat stressing. I never had that computer running at a higher than ambient temp of 75F. When the PS starts to fail, it causes the hard drives to create bad blocks. After 32 hours of running scandisk, I was able to correct the bad blocks, but had to find all the DLLís et. al. that were damaged and replace them.

As a matter of fact, I didnít know the power supplyís fan had gone bad. I started getting bad blocks on drive C and research on the net said that a bad power supply could cause such a problem. I then looked to see if the fan was on, and it wasnít.

MTBF = Mean Time Between Failures

trillianjedi




msg:388507
 2:17 pm on Aug 4, 2004 (gmt 0)

Itís the power supply.

How about if I have the PC's in the attic and the Power Supply outside the attic (much cooler)?

Not sure how long I could make the cable runs before the voltage drop becomes a problem though?

TJ

jim_w




msg:388508
 2:24 pm on Aug 4, 2004 (gmt 0)

trillianjedi

>>How about if I have the PC's in the attic and the Power Supply outside the attic (much cooler)?

There is resistance in wire. Not much, but some. The longer the wire the higher the resistance. You get to a point where it is like putting a resistor inline with the B+. How much that resistance is depends on the quality and length of the wire. Remember that the power supply was not designed for a longer wire than they come with. You would need to do some tests to measure the current limit with various lengths of wire. When resistance goes up, voltage goes down and current goes up. Ohms Law.

And without the power supply's fan, the air flow of the box will be changed and that could have an affect on the other components in the box.

[Edit]Longer wire could also result in power supply component damage from running for an extended length of time at higher current levels.[/Edit]

[edited by: jim_w at 2:27 pm (utc) on Aug. 4, 2004]

Leosghost




msg:388509
 2:24 pm on Aug 4, 2004 (gmt 0)

Exactly as described ..I used to run mine in my office when I lived near St Tropez ..average summer temp around 40 c peaked at 52 c ....they didn't like it a bit and I only used clim in the bedrooms ...

Eventually discovered the ideal way ..put them in an insulated box ( an old fridge works ok and has the shelves to make a "rack system" ) and force cold air from a reasonable sized air conditioner through the box ...pick one up for around $1,000.oo ( even less if you get one that got dropped or has damaged case ..which wont matter to you ) ...run it from an in box thermostat control ...

Bit Heath Robinson but efficient ..

trillianjedi




msg:388510
 2:32 pm on Aug 4, 2004 (gmt 0)

( an old fridge works ok and has the shelves to make a "rack system" )

I *love* that idea ;-)

OK, so basically I'm looking at air con - no other realistic option?

TJ

Leosghost




msg:388511
 2:37 pm on Aug 4, 2004 (gmt 0)

you could always build your own heat exchanger ....interesting ....and more planet friendly ..

trillianjedi




msg:388512
 2:39 pm on Aug 4, 2004 (gmt 0)

Could do with a radiator out on the roof. Still requires all the water stuff to be piped up though.

Maybe I should just sell my house and buy one with a basement?

TJ

ogletree




msg:388513
 2:40 pm on Aug 4, 2004 (gmt 0)

Thats basicly what I was saying.

jim_w




msg:388514
 2:40 pm on Aug 4, 2004 (gmt 0)

Leosghost

(the frig thing)
If it works and it is cost effective, then it is a great idea. I would at least put some kind of art work on the old frig ;-)) No magnets though!

A bit off topic, butÖ

Power supplies have always been a problem with computers. Apple and IBM both had power supply problems with over heating at one time or another. And some brain child at CBM, (Commodore Business Machines), decided that they could save money with the C64 by cutting the specification of all the power supply components in their power supplies by 10%. It would save them thousands. So on the C64, they redesigned the PS and in a moment of true genius, they took the air holes out of the power supply pack. The net result was every one, without exception, of their PSs overheated and that created a need for 3rd party power supplies that were Ĺ the price of getting another design defect from CBM.

varya




msg:388515
 4:17 pm on Aug 4, 2004 (gmt 0)

We had two Commodore 64s while I was in high school. I took one to college with me.

It never overheated and the power supply did not fail. I still have it. As far as I know, it still works, though I haven't unpacked it in a while.

bcolflesh




msg:388516
 4:31 pm on Aug 4, 2004 (gmt 0)

I've never had a heat problem w/stock C64 (or C128) power supplies - never disrespect the greatest PC ever built!

trillianjedi




msg:388517
 4:36 pm on Aug 4, 2004 (gmt 0)

My C64 with original power supply also still works (18 years old now?).

Maybe I should put that in the attic?

TJ

jim_w




msg:388518
 5:38 pm on Aug 4, 2004 (gmt 0)

I had a C64 club in Ft. Lauderdale. When I purchased my 2nd C64, it came with the redesign power supply. Believe me, they pulled them off the shelf as soon as they found it. My 2nd one had _that_ power supply, and another member of the club also had gotten one of those. The 1st C64 I purchased was over $500. It was after they started selling them at K-Mart, that the design was changed.

There was a computer store in FTL, and remember this was about 1983 or 85, that went out of business because they purchased their C64's from CBM when they first came out and K-Mart was selling them for less than this company purchased them for. And that happen to more than one business.

If you purchased one before they were in K-Marts, then you didn't get one. It was such a joke. We were using PETS in the VAQ department. Jim Butterfield, whom I have met, even knew of the problem.

You 'guys' never had a power supply that was totally sealed? No vents in the power supply? That's how you could tell.

Of course we won't mention the 1541 K-Mart swaps ;-)) I actually had 4 1541ís daisy chained at once. Of course you had to first turn on the computer, and then each one of the 1541ís as I recall. If you didnít, you would lock up the buss.

I wrote a talking terminal for it using SAM. Anyone ever use a talking terminal on CIS?

[edit]varya;bcolflesh - They were off the market a long time before you purchased your C64's[/edit]

SEOMike




msg:388519
 6:03 pm on Aug 4, 2004 (gmt 0)

put them in an insulated box ( an old fridge works ok and has the shelves to make a "rack system" ) and force cold air from a reasonable sized air conditioner through the box ...pick one up for around $1,000.oo ( even less if you get one that got dropped or has damaged case ..which wont matter to you ) ...run it from an in box thermostat control ...

Why not just get an old fridge, drill a couple of holes in it for LAN / Power wires (re-insulate the holes w/ plumbers putty or something) and let the fridge run on it's warmest setting? Then, you would have nice cool computers. Turn off the freezer and put your monitor, keyboard, KVM switch, and mouse in there! Haha, that would be a pretty cool (no pun intended!) solution!

Noisehag




msg:388520
 6:08 pm on Aug 4, 2004 (gmt 0)

I'd be concerned about possible moisture problems with the fridge concept.

SEOMike




msg:388521
 6:30 pm on Aug 4, 2004 (gmt 0)

I'd be concerned about possible moisture problems with the fridge concept.

If I'm not mistaken, most fridges have drip trays underneath of them to allow moisture taken from inside to evaporate. Also, I think most moisture inside a fridge is a result of the defrost cycle of the freezer. With that off, there shouldn't be any inside at all. I think...

jdMorgan




msg:388522
 6:32 pm on Aug 4, 2004 (gmt 0)

TJ,

Coming from a background similar to raywood's, and having some experience with accelerated life testing as well, I gotta say this is just a bad plan; Semiconductors need cool air, and electrolytic capacitors will dry out and fail in extreme heat. 50 degrees C is the maximum allowable temperature for commercial-grade ICs, and that means case temperature. Obviously, you can't maintain an IC's case temperature at 50C with any practical amount of forced air which is also at 50C. I'll second the warning on disk drives, too.

If I had to put my machines it the attic, I would build an insulated enclosure in the attic, and then run ducting to 'steal' air-conditioned air from the coolest area of the house below, through the enclosure, and return it to the house or into the air-conditioning system return. This must be forced-air, and the fan must run constantly. Actually, I'd use two fans with alarms to be sure the machines couldn't fry due to to a single-point failure.

Jim

<aside> Jim_w,
re: "B+". Man, it's been a long time since I used that term! :) </aside>

jim_w




msg:388523
 6:45 pm on Aug 4, 2004 (gmt 0)

We may be getting to the point where it would be cheaper to just put a small sub-room in the attic and just put an AC unit in the window. How much could it take to put up 3 walls and a door?

I guarantee that at 95F, the junction temperature of the ICís will well exceed 150C. I know because I clocked a bunch of 68HC11ís once in ALT, the procedure called for them to be biased only, they got so hot the lids came right off the chip carriers. It melted the epoxy. I had never seen that before then.

trillianjedi




msg:388524
 7:02 pm on Aug 4, 2004 (gmt 0)

We may be getting to the point where it would be cheaper to just put a small sub-room in the attic and just put an AC unit in the window. How much could it take to put up 3 walls and a door?

Not a lot. I could knock that up in a weekend. No window though - although I have the ex-bathroom roof vent.

What does it cost to run an air-con in the UK 24/7?

It's about 1400 watts as I recall.....

TJ

jim_w




msg:388525
 7:38 pm on Aug 4, 2004 (gmt 0)

Get a wall unit with a thermostat, and it wonít really run 24/7. And if the room is small enough, it shouldnít run very much. Put some insulation between the studs, and it will run even less. You would not need a window to the outside world. Just cut a hole in the wall to exhaust the AC, even it if exhausts into the attic, who cares. Then a tube for the water to drain somewhere and presto-chango, your in business. My AC unit actually has a pump to pump the water to the drain, so they do sell such things.

GaryK




msg:388526
 8:08 pm on Aug 4, 2004 (gmt 0)

I always hate to make suggestions because often they are sort of stupid.

And yet, might the solution be as simple as thinking like an over-clocker and using a system that recirculates chilled water in tubes inside the box? I once saw an episode of The Screen Savers on G4/TechTV where the entire computer was water-cooled. It also included some software that monitored the temperature in the box and could send various types of notices (e-mail, pager, SMS, etc.) when certain temperature levels rose too high. If this sounds feasible I'll be happy to do some research to find the appropriate links for you?

This 36 message thread spans 2 pages: 36 ( [1] 2 > >
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