[chuckles]

My IMAC DV SE 400mhz w/256mb RAM is running hot especially by the end of the day. I can perceive a performance drop late in the day, especially the modem. I have a clip-on fan running two feet away blowing at it's side. Any closer and the monitor is effected. I understand that the elegance of the design allows the rising heat from the monitor and the heat sink over the processor to suck cool air up through the bottom holes underneath and out through the top holes around the handle. I have been looking for a simple fan that would mount over the handle and not interfere with the monitor (preferably quietly). Does anyone have any suggestions or knowledge of a IMAC, third party fan? I am sure after designing it out and advertising the lack of need for one, Apple does not want to hear that their hot cake of a Mac is actually hot...but I would like to cool mine.

i guess you could mount a fan where the heat rises up, and force more of the hot air out .... or install an active cooler on the processor itself. I'm not sure if the internal architecture of the iMac would allow something like that though ...

Incidentally I have that same iMac! (although mine has 512mb ram). I like it, really want a cube though ... How are you sensing the temperature? If its the internal thermistor via some shareware program, those can be off sometimes .... mine doesn't seem to get that hot (and it runs constantly) but i don't give it much of a workout (i have another workstation I use more frequently, its faster)

[chuckles]

Thanks for the reply Stepson.

I love my DV SE too. I'm going to pump up the RAM soon so my gaming will be smoother. I know the software out there can be inaccurate. I used to use it on my old Duo that would get very hot. I know mainly by feeling the top, using an oven thermometer and ruling out other things that would decrease performance as the machine is up and proceeds through its day. I remember the fans that fit on top of the Pluses. It would seem easy to fit one over the handle vent. A good quality fan can be very quiet these days too.

A computer can never be too cool but can be too hot. My Ibaby is running cooler even now with the clip-on. I am going to get an IMAC platform to give it some more breathing space beneath. Other than that, I hope there is a third party fan out there rather that having to rig up my own. If I make my own I'll go into production.

Then ICool could be IRich before my IMac is IBaked.

Originally posted by <stepson>:
<STRONG>i guess you could mount a fan where the heat rises up, and force more of the hot air out .... or install an active cooler on the processor itself. I'm not sure if the internal architecture of the iMac would allow something like that though ...

Incidentally I have that same iMac! (although mine has 512mb ram). I like it, really want a cube though ... How are you sensing the temperature? If its the internal thermistor via some shareware program, those can be off sometimes .... mine doesn't seem to get that hot (and it runs constantly) but i don't give it much of a workout (i have another workstation I use more frequently, its faster)</STRONG>

[ 07-11-2001: Message edited by: chuckles ]

[vmarks]

my Rev.A iMac has a fan in it...
can you post pictures of your iMac when it is apart, both of the motherboard tray, and of the area directly above it (the bottom of the iMac after the tray is out) ??

it may be possible to sneak a low profile fan in above the processor heatsink and power it off the hard drive power connector. Your thoughts about mounting a fan on the ring of vents around the handle is a smart idea, but I'm not certain how good your skills of molding are- you'd want a circular enclosure that matches the countour of the iMac's shell, so that it seals around the perimeter of the vent holes. You'd also want a hook or rubber band to anchor the circular enclosure to the handle.

The fan would have to be mounted with the proper airflow, that is, sucking air from the inside and forcing it out the top.

Is your iMac still in warranty? do you have any difficulty taking it apart? My iMac has no thermal goo between the heatsink and processor. I suggest you check if yours is the same. If it is, you could pick up a cheap tube of thermal conductive goo at a PC (yuck!) store or Radio Shack.

[chuckles]

Thanks for the thoughtful insights vmarks!

I'm not going to attempt any major surgery right now. I have a warranty and a 3 year Applecare. Although, I am known to have some technical savvy.

I would like to check on the heat conducting 'goo' It would also be nice if I have enough room for a bigger heat sink or a small fan, but I won't do any modifications to the insides just yet.

For the top fan, or IFan�, I will use a foam or urethane donut (heat resistant), then the fan can be flat and the ring will make the seal.

Remember the main design constraint now is the sound. It's hard to find a quiet fan without spending $20+. Radio Shack has some but they are noisy. Also, they must not interfere with the display. Magnetism is tricky. Avoiding true Gaussian blur ups the cost of the fan too.

If we keep thinking on this thread I'm sure we can iron out all the issues. Maybe just in time for a cool running IMac with a flat screen to be released.

Cheers!

p.s.
Macworld New York this year rocked!

Originally posted by vmarks:
<STRONG>my Rev.A iMac has a fan in it...
can you post pictures of your iMac when it is apart, both of the motherboard tray, and of the area directly above it (the bottom of the iMac after the tray is out) ??

it may be possible to sneak a low profile fan in above the processor heatsink and power it off the hard drive power connector. Your thoughts about mounting a fan on the ring of vents around the handle is a smart idea, but I'm not certain how good your skills of molding are- you'd want a circular enclosure that matches the countour of the iMac's shell, so that it seals around the perimeter of the vent holes. You'd also want a hook or rubber band to anchor the circular enclosure to the handle.

The fan would have to be mounted with the proper airflow, that is, sucking air from the inside and forcing it out the top.

Is your iMac still in warranty? do you have any difficulty taking it apart? My iMac has no thermal goo between the heatsink and processor. I suggest you check if yours is the same. If it is, you could pick up a cheap tube of thermal conductive goo at a PC (yuck!) store or Radio Shack.</STRONG>

[vmarks]

Debates have been held on quiet fans for years.

PC overclockers rage on about what the biggest heatsink/quietest fan combination is.

either the panaflow or the fop-32 http://www.turbotech.ch/articles2001...balwin-01.html

basically, any ball bearing fan (not sleeve bearing) should be good. go to the next PC show at the state fair and pick up any nice looking fan... and if you don't mind sacrificing a little efficiency for reduced noise, if you run it at 7volts it will be almost completely quiet.

what color is your iMac? have you thought about molding this doughnut out of sculpey or epoxy instead of urethane?

My iMac uses a tall 80mm fan for it's internal cooling. I doubt that the magnetic interference from the motor would affect the screen much- the screen is shielded - if it weren't, the speakers would affect it.

Victor

I have one of the new imacs with the cd-rw and it gets hot. Small Dog Electronics sold me a little item called "uniriser" which rises the entire imac up about six inches where there is more airflow under it. I use a battery operated fan right under the computer when it is hotter and it doesn't interfer with the monitor.

Apple says not to worry about the heat and I also have that 3 year AppleCare, so I'm not going to worry.

Hope this helps.

[chuckles]

Glad to hear about the Pannaflow and Fop-32!

The ones from Radio Shack are ball bearing fans and it's great to hear that running it at a lower voltage will cut the sound is important.

I have a Graphite DV SE 400mhz. I have peripherals of the other colors so my desk is a jovial jelly bean bag of computing. I am always happy to sit before a Mac, esthetically and ergonomically pleasurable always.

I may mold something instead. I'm still contemplating.

The monitor, although shielded, is not the item worth shielding. The speakers are especially designed to function close to the monitor tube and it is the speakers that are shielded. This is because you shield magnetic devices especially otherwise it effects the Cathode rays that shoot out of the color guns to energize the phosphors in the tube (i.e.CRT). Magnets are what you have to watch out for (pun intended). You can try to put a magnet close to the screen (note: hold it close only briefly, I assume no liability for this nifty science experiment). There will be some giggling of the picture and the distinctive Gaussian distortion as the magnetic fields interfere.

The first desk clip-on fan that I bought is very quiet but if held next to the screen, it distorts noticeably. A second clip-on fan that I just bought which is smaller and is now clipped to the handle. It pulls the air straight up out of the top holes. It does not interfere with the screen. Everything is very cool now. Although I have a fan circus. Luckily, for most sound intensive situation I use headphones.

thanks again for participating in this discussion

Originally posted by vmarks:
<STRONG>Debates have been held on quiet fans for years.

PC overclockers rage on about what the biggest heatsink/quietest fan combination is.

either the panaflow or the fop-32 http://www.turbotech.ch/articles2001...balwin-01.html

basically, any ball bearing fan (not sleeve bearing) should be good. go to the next PC show at the state fair and pick up any nice looking fan... and if you don't mind sacrificing a little efficiency for reduced noise, if you run it at 7volts it will be almost completely quiet.

what color is your iMac? have you thought about molding this doughnut out of sculpey or epoxy instead of urethane?

My iMac uses a tall 80mm fan for it's internal cooling. I doubt that the magnetic interference from the motor would affect the screen much- the screen is shielded - if it weren't, the speakers would affect it.

Victor</STRONG>

[ 07-25-2001: Message edited by: chuckles ]

[chuckles]

Yes indeedy stepson.

That's my plan. Pull more out where it's supposed to rise. I will have to check on the power capacity of the architecture to see if and how one could add an active cooling system...thingy. Since I am under warranty, I will only attempt external solutions for now.

Buy a cube fast! It's a clear museum piece. Beautiful design and great performance. I would like to chain a bunch of them up together and have them parallel process (please take the hint Apple, and remember you heard it from me at MacNN!).

p.s.: MacNN rocks!

Originally posted by &lt;stepson&gt;:
<STRONG>i guess you could mount a fan where the heat rises up, and force more of the hot air out .... or install an active cooler on the processor itself. I'm not sure if the internal architecture of the iMac would allow something like that though ...

Incidentally I have that same iMac! (although mine has 512mb ram). I like it, really want a cube though ... How are you sensing the temperature? If its the internal thermistor via some shareware program, those can be off sometimes .... mine doesn't seem to get that hot (and it runs constantly) but i don't give it much of a workout (i have another workstation I use more frequently, its faster)</STRONG>

[chuckles]

AppleCare has always meant peace of mind to me too!

Thanks for the skinny on the 'Uniriser" I have been shopping around too. I want one that can rotate. The extra air space below certainly makes for better air flow.

Critical reminder: The Imac was designed to have the heat radiated off the heat sink over the processor. This is done by convection. The heat of the monitor's tube (CRT) pulls the heat that is already being radiated from the motherboard. The air flow goes in through the bottom holes (cool air), past the motherboard and processor (hot but sinked) and past the tube (hotter than the processor but deliberately above the processor so it's heat is not added to the mother board's), and then out the top. All elegantly by convection.

Sooooo, putting a fan beneath the Imac to pull the air down may be bad for the motherboard and processor. The CRT is probably the biggest heat producer in the Imac, luckily above the motherboard by design. I want a riser for airflow and perhaps some extra desk space beneath. If the fan below blows up into the bottom holes, then you are augmenting the intended air flow, but best to pull rather than push.

This is why I am struggling to pull the air out the top, as quietly and as elegantly as possible.

Note: Apple certainly knows what amount of heat the internals of the Imac can endure. Most of my heat is from the monitor (hopefully). But as I have said before, and is historically noted, computers are happy if they are clean (dust free) and cool. The cooler the better.

So try to get a fan above rather than below.

I can see happy dancing Imac's everywhere!

Preferably cool ones (with flat screens!)

regards

Originally posted by &lt;MacSis&gt;:
<STRONG>I have one of the new imacs with the cd-rw and it gets hot. Small Dog Electronics sold me a little item called "uniriser" which rises the entire imac up about six inches where there is more airflow under it. I use a battery operated fan right under the computer when it is hotter and it doesn't interfer with the monitor.

Apple says not to worry about the heat and I also have that 3 year AppleCare, so I'm not going to worry.

Hope this helps.</STRONG>

What do you mean by reduced performance? The only problem I can imagine observing as a result of too high a temperature is that the computer will stop. I have seen that at home when the kids forget to take off the dustcover from our iMac when they use it. After 30 minutes or so it just shuts down. In other cases you might see freezes or other glitches. I can't imagine that heat would cause anything to simply slow down.

If the iMac is simply out in the open (not tucked into a little pigeon-hole in some kind of shelving) then it should get plenty of circulation. If you want to try to add a fan just put a very small desktop fan near the top grille and have it pulling more air out of the iMac. It doesn't need much to help it out.

[chuckles]

Interesting...
Thanks for ruminating my..ur...room.

My performance drop is defined as the system freezing or programs quitting or freezing with greater frequency. It would seem that your imagination is correct. "The computer will stop" is a fairly broad but accurate observation. I find, more specifically, that any chip (processor) that overheats begins to evoke chaotic behaviors outside the designed functioning. Irregularities, if you may. For the main processor, this erratic behavior would cause a shutdown of the system. The computer can't do anything if the processor isn't in a happy state of affairs. For an internal modem, disconnects will be more likely and increase frequency or not work at all. There are a number of things on a motherboard that can go 'glitchy' when the heat rises above the stipulated temperature range. I would argue that before a complete freeze, one could recognize a difference (i.e Just Noticeable Difference) in performance. This could include an observed slow down in general processing or the specific processing of a program or card.

In the old days (I was lucky enough to visit the Coast Guard's AMVER system on Governors Island occasionally), computer facilities were super cool to keep the processors happy and dust free to keep the magnetic media clean. We have come a long way since then, although super computing is still cooled and dust protected. We little computer users have everything we need designed into the box. The magnetic media is sealed (drives), the motherboards are cooled with sinks and fans and monitors are flat cool and take less power (also better on our eyes). Imac cut power consumption and noise by elegantly designing out the fan. Such are the advances of technology. Faster, smaller, cooler processors still generate heat, with more as the day proceeds. Anyway, those who know my forum threads know I can be long winded. I just want that long wind out the top of my Graphite friend.

Indeed, I have a small fan blowing sideways over the top and bottom of the Imac as already mentioned. It sends a cool stream of air beneath and blows the hot away off the top. Yeah!

The recent addition of a small fan clipped to the handle, although quiet, transfers the fan motor's resonance to the Imac casing and becomes noisier. Sadly an unusable solution. It was a cute fan too, that didn't interfere with the monitor. Oh, well.

Thanks again for your input. This is a very useful thread for me.

p.s.: I only keep pigeons, in my pigeon holes.

p.s.s: Those poor computers in hot climates. The "Fop' reading was very useful although I have not found anything on the Panaflow yet. Parenthetically, having an air conditioner now in my room does help with ambient cooling. But my performance inconsistencies, whether the processor or modem, happen late in the day after it has been working for a while. That is when I 'perceive and observe' degradation of performance.

z;^}

(become a member of MacNN, it's easy and soooo satisfying!)

Originally posted by &lt;neutrino23&gt;:
<STRONG>What do you mean by reduced performance? The only problem I can imagine observing as a result of too high a temperature is that the computer will stop. I have seen that at home when the kids forget to take off the dustcover from our iMac when they use it. After 30 minutes or so it just shuts down. In other cases you might see freezes or other glitches. I can't imagine that heat would cause anything to simply slow down.

If the iMac is simply out in the open (not tucked into a little pigeon-hole in some kind of shelving) then it should get plenty of circulation. If you want to try to add a fan just put a very small desktop fan near the top grille and have it pulling more air out of the iMac. It doesn't need much to help it out.</STRONG>

[ 07-26-2001: Message edited by: chuckles ]

[ 07-26-2001: Message edited by: chuckles ]

[vmarks]

Chuckles,

you want 7-12 volts of power for that fan of ours (yes, I'm beginning to take ownership of the idea, hope you don't mind.)

In a desktop unit where there are extra power connectors for additional drives, you simply connect to a positive and negative (red and black, don't use the yellow and black)and it gives the 12 volts necessary to continously drive the fan. you *COULD* put a power extender from the drive in your iMac and run it out the back and up to the top, but it'd be a little odd... another alternative is to use a cheap pc power supply. You'll want to use a potentiometer to adjust the voltage to the fan, or knock it down with a small resistor. As for shielding, the inside of the ring that suspends the fan could be painted with the shielding paint used on the inside of electric guitars, and the bottom and top could have a perforated metal shield. That ought to be sufficient, no?

Any other things I've forgotten?

Victor