cooling door

Deepak Jain deepak at ai.net
Mon Mar 31 20:03:21 UTC 2008




Matthew Petach wrote:
> On 3/29/08, Alex Pilosov <alex at pilosoft.com> wrote:
>> Can someone please, pretty please with sugar on top, explain the point
>>  behind high power density?
>>
>>  Raw real estate is cheap (basically, nearly free). Increasing power
>>  density per sqft will *not* decrease cost, beyond 100W/sqft, the real
>>  estate costs are a tiny portion of total cost. Moving enough air to cool
>>  400 (or, in your case, 2000) watts per square foot is *hard*.
>>
>>  I've started to recently price things as "cost per square amp". (That is,
>>  1A power, conditioned, delivered to the customer rack and cooled). Space
>>  is really irrelevant - to me, as colo provider, whether I have 100A going
>>  into a single rack or 5 racks, is irrelevant. In fact, my *costs*
>>  (including real estate) are likely to be lower when the load is spread
>>  over 5 racks. Similarly, to a customer, all they care about is getting
>>  their gear online, and can care less whether it needs to be in 1 rack or
>>  in 5 racks.
>>
>>  To rephrase vijay, "what is the problem being solved"?
> 
> I have not yet found a way to split the ~10kw power/cooling
> demand of a T1600 across 5 racks.  Yes, when I want to put
> a pair of them into an exchange point, I can lease 10 racks,
> put T1600s in two of them, and leave the other 8 empty; but
> that hasn't helped either me the customer or the exchange
> point provider; they've had to burn more real estate for empty
> racks that can never be filled, I'm paying for floor space in my
> cage that I'm probably going to end up using for storage rather
> than just have it go to waste, and we still have the problem of
> two very hot spots that need relatively 'point' cooling solutions.
> 
> There are very specific cases where high density power and
> cooling cannot simply be spread out over more space; thus,
> research into areas like this is still very valuable.
> 


The problem with "point" heating is often that the hot point is then the 
*intake* for other equipment. If you spread your two T1600s into 10 
racks (i.e. skip 2, drop one, skip 4, drop 1, leaving two at the end) 
your hot point problem is much less of a concern.

If you bought 10 racks... not in a row, but SURROUNDING (in each of the 
rows opposite the cabinets)... Say 12 (a = vacant, b,c = T1600)

aaaa
abca
aaaa


You would be doing everyone in your datacenter a service by a) not 
thinking linearly and b) providing adequate sq ft space to dissipate 
your heat.

Deepak



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