I'm probably one of the greatest proponents of hard drive cooling.  I've tried the ones with two tiny fans that sit in a 5.25" gizmo of one kind or another.  Both with the fans in the front and the fans in the rear.  And, some with air filters that plug up with dirt and never seem to get cleaned out.
All those things that I wasted my money on are history.

I even spent $49 for a cooler that seriously wet the bed.  I think it was called a "Hermanator".  
Go Figure!

As for hard drive temperature measurements, I use a digital temperature sensor.  
The first digit of my left hand.  
If I lay my finger on the drive and it makes me say "Ouch!!!!!!", it's too hot.

Just for grinns, I just tested (digitally)  the temp of my two SATA HD's that have been on now for about six hours.
There is NO detectable temperature there at all.  Both are essentially at room-temp.

Here's my backup drive, with 5.25" bay spacers and VIO 'two-fan' cooler, mounted in an upper drive bay.  


If this pic is too large for this forum, maybe some kind soul (moderator) will shrink it for me.

At just $4 or less for the VIO two-fan coolers, keeping hard drives cool should be well within the price range of almost anyone.  I order them six at a time, to keep shipping costs down.

Cheers,
The Doctor  

DrWho2006 wrote on Apr 22^nd, 2007 at 11:28am:


I got the fans from CWC group, installed them. I could touch the top of the drives and the temp of the drives feels about the same as room temp. In the past, before the fans, they used to be real hot. Now I am a believer in the fans which cost less than $4 plus shipping.

Here are my other comments on the fan package.

1. The screws that came with the package were of wrong size and did not fit the bottom of HDs.
2. There were no offsets in the package. Fortunately I had some of them in my tool kit.
3. The power connector is long enough and nice.
4. The model I got was Xper Hard drive cooler model HC-350.
5. CWC was very responsive. Shipping prompt. When they did not hava a particular color in stock, they called me immediately and everything was taken care of. I also inquired about the ball bearing vs non ball bearing versions. Was told they have been shipping these coolers since 1990 and have had no problems. Would order again with the company.

Overall, I think you have the best bargain for the money. Have had HD failures in 1-3 years and am now convinced they are due to heat.

Note: To cut down shipping costs, order them at least a doz by pooling with your friends if necessary. The local store is selling similar fans for $10.00.

/me 

Pleonasm wrote on Apr 22^nd, 2007 at 2:17pm:


Yes.

Quote:


I have installed them in 3-1/2" bays. It took some extra space; almost one bay. Since I had extra bays there was no space problem.

Quote:


No switch on the fan to adjust the speed.

Quote:


No noticeable increase in noise. Could not even tell there were two additional fans without looking at them.

/me 

Pleonasm wrote on Apr 22^nd, 2007 at 3:53pm:

As the fan is attached to the bottom of the HD, each HD needs at least 3/4" additional space (without the offset) and 1 " space with offset,  hence would not fit in a single bay.  However, even with a single bay, if there is space at the bottom of the bay, then a fan can be added.

We may want to explore if there are any skinny fans which when added to a HD will fit into a single bay. On the other hand, I have always tried to avoid installing drives close to each other since additional space in between drives helps circulation (in all my cases, the space has not been a problem with 2 HDs.)

Hope this helps.

/me 

I worked through many different types of coolers and ways of mounting drives till I came up with the method I now use.
The questions about noise, etc. have already been answered.  Cool operation with virtually NO noise.
I just leave the side panels off of my tower, so heat buildup in the case is really NO problem.

And at less than $4, it's sure not going to break the bank.

When you start adding things to a PC that the original designers never counted on, you sometimes have to get creative.  When mounting the drives+coolers in the lower drive bays of a mid tower, you sometimes have to bend out the little tabs that the drives normally sit on.  Again, NO Biggie!

Main HD in a lower drive bay, with tabs bent out.

When there are NO drive bays, like in a little DELL, there are still ways.......( get inventive )
I'm shipping a rebuilt Dell to Illinois this week, that I did major revisions to.
The original drive failed (burned up) because of little or NO drive cooling air reaching the bottom of the drive, where all the heat is generated.

Here's the HD bracket for the Dell, providing very poor circulation against the bottom of the drive.


So I cut out the grill over the drive:


Then I installed the 1/4" brass standoffs and then mounted the cooler to the drive.


Then returned the whole drive + cooler + drive bracket, back into the case.


Now this new hard drive will stay as cool as a cucumber and should last a long time.

Even laying the drive upside down in the bottom of the case is completely acceptable, in cases where there is just no room anywhere else.  A friend in Arkansas did that and secured the drive with pink duct tape.  I've got the picture someplace.  
Here's my own version:


How to cool a hot running external HD:  (Gimme a smile!)  


I'm sorry this post ran so long, but there's just so much to say and so little time.

Doc  

An excellent article about the Antec SpotCool fan is:  Antec SpotCool Flexible Fan System Cooler Review.

A few accessories that might be of interest to readers of this thread:

    Fan Power Extension Cable
    Fan Power Splitter Cable