External HDD enclosure cooling?

[Quattro Pete]

Say you have an enclosure like this:

https://a.co/d/hjueSkb

It has some vent holes on one end, and it is positioned vertically. It contains a traditional HDD, not SSD.

If I were to get a small USB fan for it, would I want to use it as a fresh air intake fan or hot air exhaust fan?

If intake, is there a concern I'd be blowing dust into the enclosure? Would that be harmful to the drive?

 

[Vil_Riker]

I would think passive cooling should be sufficient unless its spinning all the time.

for the fan... if air hits the fan first then dust will accumulate on the blades rather than the surfaces on the inside (i.e. push air)

 

[Quattro Pete]

I would think passive cooling should be sufficient unless its spinning all the time.

It's a home media drive and it's always spinning as far as I can tell. Computer shows HDD temp at about 45 deg C at idle, but higher when actually reading/writing data. I suppose that isn't overly warm, but I've read somewhere longevity takes a hit if drive spends too much time above that temp, even though technically it should be able to handle up to 60C.

 

[Rand]

I wouldnt worry about it much unless it was in a non-climate controlled room.. ie 95f upstairs room etc.

 

[PandaBear]

I hope you use at most 5400rpm HDD and not the 7200 ones. To your original question I always think blowing at something will cool better than extracting something by exhausting it. Ideally you want both but if you have to pick one, blowing at it.

 

[Pew]

I've always been a proponent of exhaust fan if only one fan is used, but where would you put the fan for either choices?

 

[Quattro Pete]

I've always been a proponent of exhaust fan if only one fan is used, but where would you put the fan for either choices?

In front of the side of the enclosure that has vents.

Right now I have the fan blowing at it. It reduced the temp by about 10 degrees Celsius.

I guess I could try to reverse the fan to see what impact it would have.

 

[Quattro Pete]

I hope you use at most 5400rpm HDD and not the 7200 ones.

It's 5640 rpm, WD Red Plus.

 

[Pew]

In front of the side of the enclosure that has vents.

Right now I have a fan blowing at it. It reduced the temp by about 10 degrees Celsius.

I guess I could try to reverse the fan to see what impact it would have.

Definitely, I wonder what the temps would be with the alternative fan placement. I was looking at the picture wrong, I thought the vents were in the rear. It might only be feasible to have the fan pointed in with that enclosure. The lack of a defined intake/exhaust vents in that enclosure, I'd opt to force air in.

 

[Quattro Pete]

The lack of a defined intake/exhaust vents in that enclosure, I'd opt to force air in.

Yes, using it as an exhaust fan doesn't seem as effective as intake, probably because the holes are so small.

When I use it as an intake fan, the temps are lower because the entire enclosure gets cooled by all the air that gets blown at it.

 

[Pew]

Yes, using it as an exhaust fan doesn't seem as effective as intake, probably because the holes are so small.

When I use it as an intake fan, the temps are lower because the entire enclosure gets cooled by all the air that gets blown at it.

That's my line of thinking too, the enclosure is small enough for the whole thing to benefit from an intake fan forcing air in and around, and pushing the hot air out through random orfices.

 

[JHZR2]

Pulling air as an exhaust fan will just let air move as a streamline in the lowest resistance path. Pushing air in against a near dead head should induce turbulence and then the air will escape wherever. If you add homes be strategic about it so the air doesn’t just streamline all the same.

 

[KrisZ]

Pulling air as an exhaust fan will just let air move as a streamline in the lowest resistance path. Pushing air in against a near dead head should induce turbulence and then the air will escape wherever. If you add homes be strategic about it so the air doesn’t just streamline all the same.

That doesn't often work with computer fans because most of them are low static pressure fans. Meaning, if the internal pressure is too high, they will spin without moving almost any air.

I did some testing years ago and pulling the hot air out results in lower overall temperatures than pushing fresh air in. Ideally you want a fan to push the fresh air in and a fan to pull the hot air out. But if you don't have that option, pulling the hot air out is a better option.

 

[Quattro Pete]

That doesn't often work with computer fans because most of them are low static pressure fans. Meaning, if the internal pressure is too high, they will spin without moving almost any air.

I did some testing years ago and pulling the hot air out results in lower overall temperatures than pushing fresh air in. Ideally you want a fan to push the fresh air in and a fan to pull the hot air out. But if you don't have that option, pulling the hot air out is a better option.

With this particular enclosure, the entire top and bottom are metal and essentially act as a heatsink. Blowing air at it seems to be more effective than trying to evacuate air as there really isn't much air in there and the vent slits are tiny.