Google’s Budget Containment System

A look at a flexible containment system used by Google in one of its company server rooms, which combines a metal framework with plastic air sealant curtains.

Yesterday’s Green.Net 2010 conference in San Francisco included several sessions relevant to the data center sector, including a presentation on data center energy efficiency by Google energy czar Bill Weihl. Most of Weihl’s talk reviewed approaches that Google has previously disclosed in industry conferences. But there was one slide in his presentation that will be of interest to Google watchers.

In discussing the importance of isolating cold and warm air in the data center, Weihl provided a look at a design Google uses to create a low-cost hot aisle containment pod in one of its corporate server room.

“Rather than big, complicated, expensive construction, we basically put metal end-caps on the rows,” said Weihl. “And then we’ve used effectively the kind of curtains you’d use in a meat locker in a grocery store to keep cold air from infiltrating with the hot air, and vice versa.

“The reason we’re using those is that we can put any rack in there we want. All we need to do is roll up the curtains, wheel in a rack and then drop the curtain down on top of the rack and it’s effectively sealed off,” said Weihl. “So there are very cheap solutions you can apply in virtually any data center that will greatly reduce if not eliminate the potential for the hot and cold air to mix.”

Data Center Curtains in Spotlight
Clear vinyl data center curtains are offered by vendors including Simplex, and are being used in a growing number of facilities, including high-profile sites like Sun’s Colorado data center. Steve O’Donnell at The Hot Aisle has long argued for curtains as a pragmatic approach to airflow separation. In highlighting isolation strategies using curtains, Weihl focused on best practices that are accessible to companies with modest data center operations.

Google emphasizes that many of its energy efficiency strategies can be implemented by anyone. That’s true of the curtains, but less so for the Google UPS design featuring an on-board battery, which requires a custom server build.

He noted that this design is used in a company server room, and not one of the company’s production data centers. This fits with Google’s effort to contribute to the industry conversation on efficiency without revealing the current state-of-the-Google-art found inside an existing production data center.

See Earth2Tech for more coverage and full video of Weihl’s talk, as well as a panel discussion on dematerialization featuring data center energy expert Jonathan Koomey.

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About the Author

Rich Miller is the founder and editor at large of Data Center Knowledge, and has been reporting on the data center sector since 2000. He has tracked the growing impact of high-density computing on the power and cooling of data centers, and the resulting push for improved energy efficiency in these facilities.

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  1. Steve Grant

    Assuming the material used is polyvinylchloride, am curious what Google’s insurance underwriter's position is/was on the use of PVC in this environment. Know firsthand that FM Global takes issue with it in our environment. Specifically the hydrogen chloride that is released in the event of fire and more specifically the hydrochloric acid that is produced when in contact with water vapor. We had to go with a more rigid FM approved “FM 4910” material Anyone else have to deal with this?

  2. Why is this news? Curtains have been used for years for hot aisle/cold aisle containment. Google is not the first to use curtain containment concept. Why did Bill use 80% efficiency for double conversion UPS? His numbers are old. Were there not any other new and interesting data center concepts to come from the GreenNet 2010 event?

  3. Richard Trumbull

    @Steve Grant Why would you assume that Google is using PVC? Their underwriter's position on this very well could be as follows: Are the curtains PVC? No? Ok, we're done then. Stupid question.

  4. This post makes it sound like you just have to hang the curtains, set up the door and you are ready to go. Most building inspectors require having firing suppression systems located inside the contained aisle because you have basically built a small room inside a bigger one. You will either need to have your fire suppression system re-piped to locate nozzles inside the containment, or use a brand name curtain containment system that is designed to automatically detach from the ceiling right before the fire suppression system is activated. Granted, the brand name systems are more expensive than the “meat locker” material, but it is definitely cheaper than having to modify the fire system.

  5. We've found about 50% of the time fire marshals will approve of hanging curtains and then only if fuse links are used and adequate clearance from sprinklers can be guaranteed. This still allows hot air to mix into the cold aisle but is better than nothing. Another approach is to cap the cold aisle with a panel that passively drops out of its frame in the event of a fire, providing access to sprinklers. Polargy is one of the companies that offers this.

  6. As a manufacturer and installer of containment systems for over 5 years I will add my part. Meat locker curtains first. We use them,generally as an aisle end closing and notabove racks.T There is only PVC material available that is clear and flexible (willing to learn otherwise). PVC is band as a material by many DCs and more importantly their insurance companies. Based on they wont have PVC cable sheaths so it goes for everything.The reasons above re fire are correct. There are grades of PVC. New virgin PVC and that from recycled material, which is low spec. from the fire point. I have seen it used in DIY builds, as its simple, but these DIYs dont generally thing to imform anyone either insurance, building regs or local fire departments! The USA suprisingly is less fussy than the UK and EU about fire regs. But it works very well. Down side, fire,pushing crash trollies through.Heavy and needs something to hang from. The biggest it dont look good! Why curtains to aisle ends only and then it is only rack height. Closing to the ceiling is not practicle in may DCs as the ceilings often a long way up, difficult to get to(cabletray,pipes, ligh fittings etc) very much so in retro fit. Above rack can hinder water based fire suppression and detection.No problem with gas if your system is installed correctly. On our hot aisle containment with ceiling plenum return we use a rigid material to close to ceiling.Self supporting and plastics used are higher spec than PVC. How do we stop mixing over the rack. Close of at rack height across the aisle with polycarbonate sheets. Water based fire suppression needs to have a system that allowes panels to fall away. Easy when you know how. Fire detection should not be an issue if the above floor and below are correct. Same for gas suppression. Even had containment put forward as a benifit for detection as smoke particles are less diluted and picked up sooner. There are many myths around about the benifit of CAC and can tell (as we have proof) that it works very well. Its very simple. Its not expensive. Thats my bit and hope it helps. I will follow the chat on this and help with advise if needed. Jeremy, @ eCool Solutions.

  7. We have been supplying strip curtains for data centers for many years. There are various types of strip curtains, with different formulations....For Data Center anti static strips rated by the California state fire marshal are common. The strips are considered self extinguishing (short flame spread) and are typically hung from drop ceilings, uni strut or a custom frame...Haven't heard of these strips being rejected by insurance cos...There are imported materials in the US market that may not have the fire rating which could make them unacceptable to certain projects

  8. This is a very interesting idea for use in large centers where the hot air pockets never seem to go away no matter how much a/c you install. I will have to play with this idea one of our server rooms and see how it works out.

  9. Joshua Price

    In the instance of a stratified air design, where air collects in a raised subfloor plenum and is distributed through perforated floor tiles (as opposed to overhead air delivery), containment is certainly not new technology at all. Furthermore, the poorman's approach that is being touted by Google (as is explained above) does virtually nothing in way of preventing mixing above the point where the curtains end. Simply put, if they do not provide full floor to ceiling grid (or return grill) containment they are more useless than effective. The reason being is that the key in any DC enviroment is to prevent chaos cooling conditions in the center. The term chaos cooling refers to the mixing of hot and cold air currents in the center itself (no matter if it is in the aisle or above it). It is a serious concern, no matter if the primary objective is heat ventilation or heat exchange as this condition seriously impacts efficiency and equipment performance in either instance. Moreover, It is arguably more harmful in a heat exchange application, where less preferred mixed air reaches the heat exchanger (e.g. evaporator coil, etc) thereby hampering proper heat exchange (or loading). However, such conditions are somewhat preventable (or maybe controllable) in a stratified air system through PROPER full aisle containment only, not rack level containment. Furthermore, the jury is still out on the effectiveness of containment for any design that uses overhead delivery (not to mention their effectiveness in the dreaded older "legacy" misalligned row type centers). Therefore, Google's penny pinching method is not likely to provide any real long term return on investment and is laughable.