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RE: DATACENTER: AC and colo sizing question.
I thought you were hypothesizing. I didn't notice the "real question" part
intially. Maximum operating temperature is specific to the equipment and
is usually listed in the manual. I know that Ciscos usually shut
themselves down at above 140F, Suns at aorund 110 or even less and Intel
boxes usually keep running until the drives or CPU is permanently damaged.
I think drives go out first, then the processor... I'd say anything above
90 is harmful.
But I think the biggest challenge will be humans and the
building/fire/safety/osha/whetever regulations.
Grisha
On Thu, 10 Feb 2000, David Labuskes wrote:
> Wasn't expecting to remove oxygen or remove cooling from humans. Does this
> mean you can't help with a real answer?
>
>
>
> -----Original Message-----
> From: [email protected] [mailto:[email protected]]
> Sent: Thursday, February 10, 2000 11:21 AM
> To: David Labuskes
> Cc: [email protected]
> Subject: RE: DATACENTER: AC and colo sizing question.
>
>
>
> What about humans, who can't stey too long in temperature above 75?
>
>
> On Thu, 10 Feb 2000, David Labuskes wrote:
>
> > I've been working on an idea...
> >
> > My question is this. Everything about data center environmental issues is
> > centered around ambient temperature, etc. I recognize that these should
> be
> > 75 degrees, 55 humidity, etc. But if you put your hand next to the air
> > exhaust of a server or even just touch one...you know that they are hotter
> > than 75 degrees.
> >
> > My thoughts are to reduce the size of the "room" dramatically and create
> an
> > environment of dust free rapidly moving air that will allow for the
> exchange
> > of heat at a rapid pace. To make it all work though, I need to know what
> > the maximum operating temperature is for this equipment. Not the "room"
> > temperature. But more realistically, the motherboard or circuit board
> > operating limitations.
> >
> > I apologize if the question doesn't make sense. Please feel free to reply
> > privately or via the list.
> >
> > Thanks in advance for any and all information.
> >
> > David Labuskes, RCDD/LAN, CSI
> >
> > -----Original Message-----
> > From: Julian, Dennis R. [mailto:[email protected]]
> > Sent: Thursday, February 10, 2000 9:46 AM
> > To: foo; [email protected]
> > Subject: RE: DATACENTER: AC and colo sizing question.
> >
> >
> > I agree, an educated client is a wonderful thing. In regards to peak
> > cooling if you have over cooling what you lose is the ability to control
> > humidity. It may feel cold and damp. The other concern is if the A/C
> units
> > have compressors rather than a central chilled water source the increased
> > number of starts resulting from short cycling may shorten the unit's life
> > and increase the maintenance required.
> >
> > But being over cooled is better than over heated. One way to deal with
> this
> > is through multiple units and redundancy. With multiple units you can
> stage
> > in by manually or automatically turning on additional units as the load
> > increases (or as the temperature rises). This can be done by using
> > redundant units that also provide the ability to maintain cooling when
> > unit(s) are down for maintenance or problems.
> >
> > Dennis R. Julian, P.E., RCDD
> > Technical Associate
> > Critical Facilities Design Group
> > van Zelm Heywood & Shadford, Inc
> > Mechanical and Electrical Engineers
> > 29 South Main Street West Hartford, CT 06107-2420
> > Phone (860) 521-4329 x373 Fax (860) 521-5620
> > [email protected]
> > www.vanzelm.com
> >
> >
> > -----Original Message-----
> > From: Roeland M.J. Meyer [mailto:[email protected]]
> > Sent: Wednesday, February 09, 2000 10:40 PM
> > To: foo; [email protected]
> > Subject: RE: DATACENTER: AC and colo sizing question.
> >
> >
> > > From: [email protected]
> > > [mailto:[email protected]]On Behalf Of foo
> > > Sent: Wednesday, February 09, 2000 6:54 PM
> > >
> > > Ken Woods wrote:
> > > > On Wed, 9 Feb 2000, foo wrote:
> > > >
> > > > 8.34 A @ 120 = 1 KVA
> > > > Total KVA * 2728 = BTU
> > > > 12000 BTU per ton of air.
> > > >
> > > > Also add whatever heat load you have from lights, people, walls,
> support
> > > > equipment (UPS and air unit, etc)
> > >
> > > My question is not so much how to calculate cooling for a known
> heat/power
> > > load, but rather how to deal with transient increases in load while
> > > equipment is being staged or housed temporarily or whatever as well as
> > > gradual increases over time (as equipment is added permamnently). As I
> was
> > > led to believe that engineering cooling for peak load would be very
> > > inefficient and/or ineffective during times of non-peak load, I'm
> curious
> > > as to what your suggestions may be to alleviate this problem.
> >
> > It is not near as inefficient as losing equipment due to heat-death. This
> is
> > the inevitable result of NOT planning for peaks. Generally, add up the
> power
> > usage numbers on all the equipment you are installing, allow for 5 warm
> > bodies, add 30% for additional equipment arriving on a 100 degree day, and
> > you should have enough. I like 70F +/- 5F.
> >
> > > > If I may, I suggest you hire an engineer that has a basic grasp on
> what
> > > > you're trying to do, and isn't trying to guess. There are several on
> the
> > > > list that would be glad to work for you.
> > >
> > > I'm not at all adverse to hiring someone to help us with this, however
> I'd
> > > like to understand it a bit better before going that route. In my
> > > experience plenty of facilities haven't gotten this quite right even
> with
> > > "experts" on board (I've been a customer or visitor in quite a few
> > > Internet Data Centers with serious environmental problems), so simply
> > > signing away the responsibility to some third party without first
> > > educating myself a bit doesnt make me entirely comfortable.
> >
> > You'll find, on investigation, that recommendations were usually
> > under-followed due to desire to reduce costs. The cost difference between
> a
> > 3 ton AC unit and a 5 ton unit is amazing. Many managers figure that they
> > can "tough it out" during the few hot days, or decide to "policy exclude"
> > additional equipment. More often, that manager gets another offer,
> elewhere,
> > and their successor doesn't have their notes and they have to take the hit
> > on their watch.
> >
>