This this even a thing?

[Cowboyk56]

Hi, Im looking for a mini m.2 connecter that gives ability to have a fan header. I have HP EliteDesk 705 G4 DM and it has a wifi card slot, want to take out wifi card and add in m.2 card that can give one or two fan connects. 

 

[Cowboyk56]

im looking into usb to fan adapter for it, but want to add more cooling if possible or quite noise. Its on its way, but this is exact model in this video 

 

[Cowboyk56]

http://h10032.www1.hp.com/ctg/Manual/c06516423

[Biohazard777]

8 minutes ago, Cowboyk56 said:

but want to add more cooling if possible or quite noise.

Unnecessary.
While under normal load you can't even hear these things.
I've got a couple of Lenovo M720q, very similar to what you are getting, heck even under full load on all cores it makes very little noise (at least twice quieter compared to my laptops).

Also, it is questionable if slapping more fans onto it would make any kind of difference (given the heatsink and cooler design of these 1L tiny PCs), you might just introduce more noise without any notable performance increae.

It is essentially a laptop without a kb, touchpad & screen. And the CPUs in them are typically low TDP.
Look up tests on how much of a difference cooling pads make for gaming laptops (spoiler, not that much, and those use a lot higher TDP components).
 

28 minutes ago, Cowboyk56 said:

it has a wifi card slot, want to take out wifi card and add in m.2 card that can give one or two fan connects. 

If you have no use for m.2 wifi that comes bundled (like I didn't) there are better uses for that slot.
You can find 2.5Gbs NICs, additional SATA ports, etc. (obviously do your own research and check compatibility).

 

[IntMD]

I've got a Prodesk 400 G6 on my desk at work. I've never even heard the fan spin up on it unless I was trying to make it purposely and it's only an arms length away from me.