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RE: DATACENTER: AC and colo sizing question.
My datacenter goes on "yellow" alert at 80F, all non-production,
non-essential equipment is shut-down. At 90F, we go to "red" alert and start
shutting down the whole thing, on the theory that a few hours of lost
operation is better than lost days due to repairs.
> -----Original Message-----
> From: [email protected]
> [mailto:[email protected]]On Behalf Of [email protected]
> Sent: Thursday, February 10, 2000 10:57 AM
> To: David Labuskes
> Cc: [email protected]
> Subject: 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.
> > >
> >
>