Please join Dell Enterprise Strategists and Principal Engineers as we cover best practice around Chillerless Facilities and Fresh Air Cooling.

Our distinguished panel includes:

Dave Moss - PG Principal EngineerDave Moss is a Dell Principal Engineer responsible for data center cooling product strategy. He has been with Dell 20 years and has over 20 US patents.

Jon Fitch is a Dell Principal Server & Storage Reliability Engineer and he has spent the last three years conducting experiments on the feasibility of doing chiller-less fresh air cooling of data centers in a variety of world-wide climate zones. Jon is an active member of the ASHRAE TC9.9 Mission Critical Facilities committee.

Paul Artman is a Dell Enterprise Technologist.

Eric Wilcox is a Dell Strategist.


Technical Community - Background Reading


Dell Power & Cooling Whitepapers - A Collection of Dell Power & Cooling Studies and Whitepapers with best practices.

Dell IT Solutions Support Chillerless Data Center Deployments (PDF Whitepaper)

Data Center Operating Temperature (PDF Whitepaper) What is the ideal temperature for your data center? Dell has a recommendation. Find out more in this paper.

Facility Cooling Failure Ride-Through (PDF Whitepaper) How much time does your IT equipment give you in the event of chiller failure? Read Dell's position based on years of research.


Chat Transcript

Dell-KongY Welcome svela :)
svela Thanks :)
Dell-KongY We will get started in just a few minutes.
Dell-KongY Welcome Delta!
Dell-KongY Alright. Let's get started.
Dell-KongY Today's chat is covering Best Practice Chillerless & Fresh Air Cooling for Data Centers
Dell-KongY We have Dell's finest data center power & cooling Smes with us today.
Dell-KongY Dave Moss is a Dell Principal Engineer responsible for data center cooling product strategy. He has been with Dell 20 years and has over 20 Us patents.
Dell-KongY Jon Fitch is a Dell Principal Server & Storage Reliability Engineer and he has spent the last three years conducting experiments on the feasibility of doing chiller-less fresh air cooling of data centers in a variety of world-wide climate zones. Jon is an active member of the Ashrae Tc9.9 Mission Critical Facilities committee.
Dell-KongY I also have Milly Pellizzari, who is the Sr. Outbound marketing Manager for Power & Cooling
Dell-KongY So Dave and Jon, what are the new server classifications introduced by Ashrae? And why should I care? And how does this tie into Chillerless facilities / Fresh Air cooling?
dell-DaveM Ashrae recently announced two new classes of It equipment aimed at enabling chiller-less facilities
dell-DaveM These would essentially extend the temperature ability to either 40 or 45C (104 or 113f) from the current norm of 35C (95f)
dell-DaveM Most locations around the world do exceed 35C (95f) but not by that much and not very often
dell-DaveM A growing trend for data centers is to use economizers which make use of cool outside air temperature
dell-DaveM Economizers, in fact have also recently been mandated by an Ashrae standard that will affect much of the Us once it is adopted
Dell-KongY Hi ceu!
Dell-KongY Hi Oneseventeen!
Dell-KongY Hi Jason :)
jasonpowell Party in the Tech Center!
dell-DaveM It doesn't take too long operating on economizers, especially if you push the usage to higher and higher temperatures to realize that the building's chiller is not being used that often. That gets folks interested in potentially looking at a chiller-less facility design
jasonpowell What the? Where is everyone??
Dell-KongY Please click Action -> Recent Room History to catch up on the previous conversations
ceu hi all
Dell-KongY Welcome Carlodim!
dell-DaveM Most of the current interest is in the Euro Telecom community and the big web companies like Microsoft, Google, etc, but the interest is likely to spread
Dell-KongY Please click Action -> Recent Room History to catch up on the previous conversations. And as always a chat transcript will be available tomorrow
Dell-KongY If you have a question please feel free to ask away :)
Dell-KongY we don't bite... i promise ;)
dell-DaveM Ashrae wanted to get ahead of the curve and put out recommended limits so all the vendors woulld have something to shoot for
carlodim Hi Guys, thanks :)
Dell-JonT As Dave mentioned, the next big step in fresh air cooling is being able to build data centers without chillers.
dell-DaveM By extending It equipment temperature and humidity limits, you increase the available locales in which a chillerless facility could be done
Dell-JonT Industry standard 35C equipment limits these fresh air data centers to either cool northern climates and/or having to have a chiller.
Dell-MillyP What solutions does Dell have that can handle the recommendations from Ashrae? Can you talk about the validation and testing done to prove this out?
Dell-KongY Here's a great whitepaper on Dell It Solutions support Chillerless Data Center deployments http://media.community.dell.com/en/dtc/attach/chillerless facilities whitepaper.pdf
Dell-JonT Dell has done extensive validation testing on several servers and we have shown they are capable of excursion based operation up to 40 and 45C. These and other Dell products will enable the construction and operation of chiller-less data centers in a much wider range of world wide climates.
Dell-KongY And please remember to right click links :)
jasonpowell I saw a recent study talking about how up'ing your data center to 80deg would save a good chunk of $$$ and cause no more hardware failures than norm.
dell-DaveM We'll point you to a whitepaper talking about 80 degrees which is a good temperature to save a bunch of $$$
Dell-JonT Good question Jason - Dell data and data from other sources indicates the reliability impact of raising your data center temperature is very small.
dell-DaveM That's what Dell recommends for compressor cooled facilities (typical data centers with Hvac)
Dell-KongY @jason - here's the whitepaper that covers Data Center Operating Temperature http://media.community.dell.com/en/dtc/attach/datacenter operating temperature.pdf
Dell-MillyP Can you share what Dell had to do to meet the new requirements so quickly? What changes were required on current Dell servers to be able to handle the higher temperatures?
dell-DaveM For chiller-less we are saying take the temperature up and follow the outside ambient.
dell-DaveM We have validated our mainstream 1U 2U and tower along with networking, storage and power distr gear to both 40 and 40C, the new Ashrae classes
dell-DaveM We were able to do this so quickly (ashrae just announced these classes in the last month or two) because we had already beeen looking at it a long time.
dell-DaveM Ashrae actually followed us somewhat on this, and we in fact helped to define the Ashrae specifics
Dell-JonT Dell has been conducting chiller-less fresh air cooling research over the last 2 1/2 years - the research we did identified several product design opportunities we have already implemented.
jasonpowell Kongy - can't get that link to open
Delta Will this increase in ambient impact component specs (power Supplies?)
Dell-KongY Welcome Jeffh!
Dell-MillyP If you change your data center temperature to run hotter, what is the potential impact to reliability?
Dell-JonT One key point i would like to make about chiller-less fresh air cooling is if you look at climate data you see that most climates (e.g. New York) spend only a small fraction of the total number of hours per year at high (e.g. 35C) temperatures. Thus, what is needed for fresh air chiller-less operation is for the equipment to be able to handle high temperaturues (above 35C) for short periods of time, not continuously.
Dell-KongY Please click Action -> Recent Room History to catch up on the conversations
dell-DaveM We made now changes to current hardware. I believe we changed some warning limits. We had thermal headroom in the sytems. There are a couple caveats. The current gen hardware is limited to 95 and requires redundant power
dell-DaveM power supply ambient agreement with vendors is maintained
Dell-KongY @jason - let me check again... it opened up but Parachat has been quirky
JeffHengesbach Hi Kong
Dell-JonT Delta - thanks for asking. Dell has very stringent component selection and de-rating guidelines. De-rating means we design our power supplies so the components are being used at Less than their max ratings even at worst case inlet temp to the Psu. This means our power supplies have quite a bit of margin to the component manufacturers specs.
Dell-KongY @jason - the data center operating temperature paper is listed under the tech community background reading / the 3rd link... apologies for the link not opening up the Pdf for you
Dell-JonT Back to Milly's question about whether higher data center temps affect reliabiltiy - if the data center uses outside air and the outside air temperature gets hot, but only for short periods of time, those periods of hot operation are so short for most climates that they have very little impact on the overall data center reliability. This point was also made in the recently released Ashrae white paper
dell-DaveM One thing about reliability. Component temperature increase (long term exposure) does have some effect on reliability. You can't confuse component temp increase with ambient increase since our fans compensate quite well for ambient
Dell-JonT Dave has a good point - system cooling algorithms are such that component temperatures don't increase linearly with the inlet ambient temperature increases. Component temp increases are typically on the order of half of the inlet temp increase. This cushions the reliability impact of higher data center temperatures.
dell-DaveM A recent set of test data I looked at for our current gen 2U had 40-50 component temps monitored and there was data for 24C ambient and 35C ambient. Over half the measured points were actually lower at the higher inlet temperature. Of the ones that were higher, it was an average of 3.5 degrees for that 11C increase in inlet. Most of the components that were on the high side of the average were hard drive...which at least is redundant in most cases. They were within spec in either case anyway
Dell-MillyP Not all customers are looking to go chiller-less right away, what benefit could they gain outside of going full chiller-less? What else should they be looking at?
jasonpowell I'm most concerned with temp changes causing hard drive issues vs server hardware personally.
jasonpowell spinning platters going through temp swings make me nervous :)
jasonpowell ie. Equallogic arrays
Dell-JonT Most hard disk drives (enterprise class) are rated up to 55C. Also, the drive temperature tends to follow the inlet temp more closely than most components because drives are typically located in the front of the box where they see the inlet air before it gets any heating.
dell-DaveM Most, I would say will not be considering chiller facilities any time soon; we're trying to get ahead of the curve and it is like a chicken/egg thing
dell-DaveM Having higher temperature capability can help in other instances. Take, for example a power/cooling outage. Temperatures can shoot up very quickly
Dell-JonT Even if the inlet goes up to 45C, this is still well below the drive spec of 55C. If you think about it from a fresh air cooling perspective, daily temperatures don't change that fast and hard disk drives have a large thermal mass so their temp won't change very quickly either.
dell-DaveM The new Ashrae classifiications provide up to 10C (18f) more headroom in a cooling failure
Dell-JonT Fyi - a major hard drive supplier was a party to writing the recently released Ashrae white paper that defined new higher temp (40 and 45C) hardware classes.
Dell-KongY you have mentioned Ashrae. Who is Ashrae? And why should It admins care?
dell-DaveM That's quite a bit more leeway for not shutting down, voiding warranty, etc
Dell-KongY @jason - great questions as always
dell-DaveM Ashrae is American Society of Heating Refrigerating and Air conditioning Engineers
jasonpowell are there recommended temperature changes over time? ie. don't exceed Xdegs/hr ?
dell-DaveM Ashrae writes standards and guidelines for buildings of all types...concentrating on heating/cooling but also profiding guidance and standards on many related topics
Dell-JonT Jason - yes, the drive suppliers do have temp rate of change specs and I am pretty sure fresh air cooled data centers don't even come close to those specs.
dell-DaveM Ashrae is "american" but does have global participation and its standards get adopted all around the globe
jasonpowell interesting
jasonpowell Is this typically a forced fresh air in method or force pulling the exhaust air out?
dell-DaveM Jon and I are both members of the technical committee for data centers
jasonpowell Guess I should go read the whitepapers :)
jasonpowell I run into many It peers that have very little cooling capability ... so this is pretty interesting stuff
dell-DaveM Essentially we are talking about economizers. There are two types. A water economizer reroutes chilled water out of the facility around the chiller and to an external form of heat rejection. You are no longer running a vapor compresssion cycle to creat the chilled water....
Dell-JonT Fyi - most fresh air cooled data centers have an air mixing chamber that mixes cold outside air in the winter with hot server exhaust air to maintain a minimum data center temp of something like 20C so your data center equipment won't see the cold temperature swings of your local climate
jasonpowell /me lives in In
dell-DaveM An air economizer is even simpler and actually much less costly (capex). It is essentially a system of louvered external vents that are controlled in conjunction with facility fans to draw in fresh and expel exhaust. This is coordinated with turning off the chiller when fresh air is being usexd
Dell-JonT If you build a fresh air cooled data center and you are willing to allow your equipment to run hotter, but only for short periods of time, you can use your chiller a lot less and use it only when the outside air temp exceeds 35C which is the max temp rating of some of your equipment
dell-DaveM A chiller-less faciliyt would do it all the time so there would be no opening or closing of vents. You'd simply have additiional fans to suck in and exhaust
dell-DaveM Another Ashrae group (as I mentioned before) just updated a spec that calls for mandatory economization in new buildings (data centers).
dell-DaveM Data centers were previously exempt
jasonpowell is this applicable to smaller sized server rooms?
dell-DaveM All but southeastern Us wwill eventually be affected once local codes adoptt
dell-DaveM There is a lower size threshold; good question
dell-DaveM I can't remember it specifically but I could let you know once I look up the standard
Dell-JonT Jason - if I understand your post correctly, you live in Indiana. Here's an interesting exercise - make a temperature histogram of your climate in Indiana. Divide the temps into 5C blocks, e.g. 20 -25c, 25-30c, etc. you will find less than 5 or 10% of the hours for Indiana are greater than 35C. If you wanted to allow excursions up to 35C, you would only have to run your chiller for 5 or 10% of the year.
jasonpowell this is very fascinating stuff
dell-DaveM And that other 5-10% of the year is likely covered by the 2 new classes of equipment, so you could go chiller-less in your location
Dell-KongY @Jon - Thanks for sharing that tidbit :)
Dell-MillyP I understand that there is some additional benefit for those data center operators who are risk averse. What is the ride-through capability inherent in this solution?
dell-DaveM I mentioned briefly earlier. Power/cooling outage produces quickly rising temperturs. I have a whitepaper recently posted on some testing I did in my lab last summer
jasonpowell and yes we're in Indiana
jasonpowell currently 89 outside and nasty humidity :)
Dell-KongY Dell's Facility Cooling Failure Ride-through whitepaper - http://media.community.dell.com/en/dtc/attach/facility cooling failure ride through whitepaper.pdf
dell-DaveM The extra cushion from 35C to 45C would provide you a bit more time. My conclusion from the testing was that facility air handlers should be backed by Ups. That increase time from seconds to minutes in which you can hit troubling temperatures.
Dell-JonT Jason - the Dell white paper we wrote recently used Chicago Illinois as a reference climate. This should be close to Indiana
dell-DaveM It is highly related to room density; the paper is explicity
wantmoore what's this that jason is telling me about having to work on servers in a 95F server room? :)
Dell-KongY Welcome wantmoore! Please click Action -> Recent Room History to catch up on the conversations
dell-DaveM 103 on my way to this building
jasonpowell Lol
wantmoore <dislike>
jasonpowell bring your shorts tomorrow!
Dell-JonT Hey, we ran the Dell fresh air cooling reaseach at 40C and 85%rh for 18 months.
wantmoore we'll need to install a shower!
dell-DaveM I'm in them now
wantmoore 85% - ouch!
Dell-JonT Yeah, it was a sauna, your shirt would stick to your back in less than 30 seconds
wantmoore in all seriousness - definitely interesting research. and probably one of the last ways conventional It shops would think when trying to get more green
jasonpowell hmmm I forsee workmans comp for heat stroke in the future ;-)
dell-DaveM Actually interesting. I was running some lab experiments over the last couple days and my room (return temp) was often 108
wantmoore can we get some hazmat suits or something with built in cooling?
Dell-JonT let me be clear, the 40C and 85%rh condition was not intended to be a real usage condition - it was intended to accelerate the time frame over which we might see temp and humidity related failures
jasonpowell our server room is prob way to small to implement this ... but I love the concept
Dell-JonT No reason it couldn't work for small and medium business too.
dell-DaveM To reiterate on temperature since that's our current direction. We like 77F as a good operational temp for compressor based cooling. The equipment doesn't mind it to go higher if using "free" methods
Dell-JonT The advantage I see for a small business with a small Dc is if they keep their fans on a Ups system and their chiller fails, then they can pump in outside air and keep their data center up. This is an advantage even if you aren't doing fresh air all the time.
dell-DaveM Funny you mention suits. I have talked to customers that have adopted warm temperatuers. One customer had gelpack coats that they could refrigerate and wear when entering the data center
jasonpowell that's awesome
jasonpowell here, before you go into the server room you better put this on ..
wantmoore <looks for welding helmet>
Dell-JonT Where were those suits back when I was doing the 40C and 8%RH fresh air research???
dell-DaveM Whether getting to the extent of chiller-less, we do have a very strong opinion that data centers should be run warmer. No real reason to run like a meat locker
Dell-KongY Time certainly flies when you're having fun
Dell-KongY I want to thank our featured guests - Dave, Jon and Milly!
Dell-KongY Thank you :)
Dell-KongY And a big thank you to the Community for joining us today :)
dell-DaveM thanks guys
Dell-KongY Again thank you everyone for your time & participation.
Dell-JonT Thanks everyone for a lively discussion ::biggrin
Dell-MillyP great discussion! thanks!
dell-DaveM Don't miss a future chat on our new Energy Smart Containment Rack
jasonpowell repost those whitepaper links again please
Dell-KongY Next's week chat will cover Powervault Md 32xx/36xx.
Dell-KongY http://media.community.dell.com/en/dtc/attach/chillerless facilities whitepaper.pdf
Dell-KongY Dell It Solutions Support Chillerless Data Center Deployments - http://media.community.dell.com/en/dtc/attach/chillerless facilities whitepaper.pdf
jasonpowell our server room is 77deg
Dell-KongY Data Center Operating Temperature - http://media.community.dell.com/en/dtc/attach/datacenter operating temperature.pdf
Dell-KongY Facility Cooling Failure Ride-through - http://media.community.dell.com/en/dtc/attach/facility cooling failure ride through whitepaper.pdf
wantmoore we were running our Dr gear at an offiste location in what was essentially a broom closet - temps easily hit 105 with frequency
wantmoore low Rh - but man - it was miserable to try and work in
jasonpowell here's our current server room temps http://bit.ly/serverroomtemp
Dell-KongY @wantmoore - I'd bet it was horrible ... ouch 105
wantmoore actually im looking at the data now... peak was actually 114
jasonpowell actually got up to 110 according to the graphs
Dell-KongY Jason & Wantmoore - if you have any further questions for Dave & Jon, please send them my way & I will get them answered for you
jasonpowell if anyone at Dell wants to do a case study let us know :)
Dell-KongY will do... we'll keep you in mind :)
jasonpowell this could be a big win for the Church It community
jasonpowell time for another conf call ... laterz!
Dell-KongY Excellent... thanks :)
Dell-KongY Thanks Oneseventeen & Jason! Take care!