LFM, CFM requirements on pc cards

[cherkey]

Hello,
Just a quick question regarding airflow specs on various cards meant for insertion into a pc: the datasheets will state something like 100 lfm required at a certain temp. Does this number refer to what should be entering the system, or what should be moving at the card itself?
Thank you,
cherkey

 

[IRstuff]

I would think that it would be for the card.

Why would a manufacturer gamble on this requirement, knowing that some other, unrelated card might block off or otherwise steal his cooling air?

TTFN

FAQ731-376

 

[cherkey]

Thanks for reply. I thought that is was for the card but that's what I've often wondered - how to guarantee that type of airflow, especially in an atx type environment. I often think that it should just say 'we operate within these temps and xx lfm will help prevent overheating'...or similar...
cherkey

 

[IRstuff]

I think that you'll find that many systems would need something like a -40ºC ambient to prevent overheating with no air flow

TTFN

FAQ731-376

 

[cherkey]

Heh, yes I agree. Yet, there is air moving within an enclosure I just can't see 100-200 lfm at pc slots so I guess I'm not sure how that can be recommended....I guess one just needs to ensure air movement within the box with limited/no obstruction in critical areas.
cherkey

 

[Twoballcane]

Just make sure that the total CFM and cross area accross CCA will give you the LFM you need.

Tobalcane
"If you avoid failure, you also avoid success."

 

[IRstuff]

A high performance system will duct the air flow to make sure that each board receives its due.

Most PCs, of course, don't all into that category.

The VXI standard for VME does include such air flow considerations.

TTFN

FAQ731-376