Thinnest laptop fan made?

I have an e7240, the heatsink fan combo sucks. I need a very thin fan to put right on the heatsink that I will splice and then power via usb. I've got maybe a few mm clearance

 

@jedisurfer1 quick googling revealed existence of 10x10x3mm Sunon Mighty Mini Fan. They also mention custom-made 2mm and below fans.

 

I've used some of those mini fans before and they barely move any air. See the specs at digikey: http://www.digikey.com/en/product-highlight/s/sunon-fans/mighty-mini-fans-and-blowers

They all move less than 1cfm, most less than 0.25cfm. That's like nothing. Unless a device is specifically designed for them I don't see it making a whole lot of difference. Just nature of the beast. Small means you need VERY fast spinning blades which would whine like crazy, and even then might be able to push only 2cfm.

You may want to see about repasting your CPU. Thermal paste may be a bad job or just old. Doesn't matter how much air you push over it if it's not transferring heat off CPU properly to begin with.

 

Get a cooler like a Notepal U3 and mod it with 12V fans.

 

There are also differences in the quality of fans. Compare the photos below of the fan in the Dell E7440 (left) and in my dGPU version of the E7450 (right).

The latter fan has to be more efficient because it has to cool both a CPU and dGPU but, impressively, it does this with less noise than the crude looking fan in the E7440 (and I suspect that the E7420's fan is similar). Better cooling performance can be achieved without the noise if attention is given to the design.

I have also noticed that the better quality fan has been used in some Skylake Latitudes which don't have dGPUs. Maybe Dell have finally realised that users don't like whiny fans and it's worth spending a few dollars on better ones. I wonder if the new fans would be intercheangeable with the old ones in which case the fix for the E7240 would be a better main fan, not an additional fan.

BTW, the smallest notebook fan I have encountered is in the Toshiba R500. It is also the noisiest.

John

 

Agreed, do a repaste first... The fan if its small will make no difference at all tbh..

 

Dell's fan control is crap, with my thinkpads I could control via tpfc, many levels and in steps. Dell has their stupid quiet, cool (fan runs full blast), ultra performance). I've triend speedfan without luck. They make shoddy fans at least for the e7240 and e7440. I do like that they have 2 easy to upgrade hard drives and very easy to replace 2 ram slots. I'm thinking about the e7270 qhd but I think these also have 2 core cpu or 4 core with no ht. I'm running around mid 40's to low 50s with repasted cpu, intel xtu undervolted -75mv offset, and throttlestop to control the multiplier. Anyone that has the e7240/e7250 knows the way it's designed it gets very warm on the bottom and not usable on your lap.

John is the dgpu fan the same dimensions as the other fan. I may try and source a dpn for that fan and replace it.

 

Unfortunately, I don't know the answer. The dGPU version of the E7450 has a different heatsink configuration and isn't easy to take apart.

It may be worthwhile hunting through the Chinese component websites such as this to see if there as a better looking fan of the correct size for your E7240.

John