Comments for Datacenter-Link Blog http://blog.datacenter-link.com Secure your reliability Wed, 08 Sep 2010 06:42:44 +0000 http://wordpress.org/?v=2.3.3 Comment on New Guidelines for Datacenters Cooling by siva http://blog.datacenter-link.com/?p=12#comment-3257 siva Thu, 23 Jul 2009 06:56:11 +0000 http://blog.datacenter-link.com/?p=12#comment-3257 Hello Ezio Sturaro Is it possbile to demonstrate 20KW per rack cooling in CFD tool. Our clients are asking a CFD demo. Our Raised floor height is 600 FFH. Is it possible to cool 20KW/rack with DX based Precision AC units, What will be the Return air temperature and Humidity condition and Supply air condtions. Is it possible to use your Active floor tile with other Precision AC units having standard plug fan. Hello Ezio Sturaro

Is it possbile to demonstrate 20KW per rack cooling in CFD tool. Our clients are asking a CFD demo. Our Raised floor height is 600 FFH.

Is it possible to cool 20KW/rack with DX based Precision AC units, What will be the Return air temperature and Humidity condition and Supply air condtions.

Is it possible to use your Active floor tile with other Precision AC units having standard plug fan.

]]> Comment on Optimize the performances of the datacenter by choosing the right cabinet. by DC Guy http://blog.datacenter-link.com/?p=31#comment-104 DC Guy Sun, 03 Aug 2008 21:19:55 +0000 http://blog.datacenter-link.com/?p=31#comment-104 A greater consideration often overlooked is the layout of the cabinets (including the hot/cod aisle configuration) in relation to the positioning of the CCU's/CRAC's. Often I have seen a cold aisle located in the centre of the return path of the CCU/CRAC - a few feet left or right would optimise the cooling and improve efficiencies. The same can be said for the vented tiles which are then deployed in the cold aisle in close proximity to the CCU/CRAC causing further short-circuits resulting in the unit working less efficiently based on the percieved return air temperature. A greater consideration often overlooked is the layout of the cabinets (including the hot/cod aisle configuration) in relation to the positioning of the CCU’s/CRAC’s. Often I have seen a cold aisle located in the centre of the return path of the CCU/CRAC - a few feet left or right would optimise the cooling and improve efficiencies. The same can be said for the vented tiles which are then deployed in the cold aisle in close proximity to the CCU/CRAC causing further short-circuits resulting in the unit working less efficiently based on the percieved return air temperature.

]]> Comment on Virtualization applications and physical machines shut down by Matteo Granziero http://blog.datacenter-link.com/?p=37#comment-94 Matteo Granziero Fri, 25 Jul 2008 10:47:54 +0000 http://blog.datacenter-link.com/?p=37#comment-94 Hello Damiano, I agree with your consideration but let me to add another point of view: the human resources optimisation. I mean that if the operator must install a shutdown client every virtual machine should use at least twice the time he would use installing the client on the phisical server. Let's imagine the human resources saving in big Data Centres such server farm, services providers, bank and insurances. Hello Damiano,

I agree with your consideration but let me to add another point of view: the human resources optimisation.
I mean that if the operator must install a shutdown client every virtual machine should use at least twice the time he would use installing the client on the phisical server.
Let’s imagine the human resources saving in big Data Centres such server farm, services providers, bank and insurances.

]]> Comment on New Guidelines for Datacenters Cooling by Ezio Sturaro http://blog.datacenter-link.com/?p=12#comment-93 Ezio Sturaro Mon, 21 Jul 2008 15:57:40 +0000 http://blog.datacenter-link.com/?p=12#comment-93 Dear Kylie, the nominal height that we suggest as minimum (from the raised floor structure) in order to grant the nominal airflow with the nominal power consumption is 350mm. In case that the height available is lower obviously the perfromances in terms of airflow and/or power consumption of active floor are penalized. Generally in order to implement the better solution able to grant a proper cooling solution for high density servers with the maximum efficiency you can contact us and our partners present world wide. Best Regards Dear Kylie,
the nominal height that we suggest as minimum (from the raised floor structure) in order to grant the nominal airflow with the nominal power consumption is 350mm. In case that the height available is lower obviously the perfromances in terms of airflow and/or power consumption of active floor are penalized. Generally in order to implement the better solution able to grant a proper cooling solution for high density servers with the maximum efficiency you can contact us and our partners present world wide.
Best Regards

]]> Comment on New Guidelines for Datacenters Cooling by kylie http://blog.datacenter-link.com/?p=12#comment-91 kylie Fri, 11 Jul 2008 01:18:51 +0000 http://blog.datacenter-link.com/?p=12#comment-91 Hi Ezio Is there a minimum floor height clearance required for the active floor grills? My raised floor is 300mm. We are currently using Uniflair Leonardo chillers in our room, but adding new blade servers and need some extra help :) Thanks! Kylie Hi Ezio

Is there a minimum floor height clearance required for the active floor grills? My raised floor is 300mm. We are currently using Uniflair Leonardo chillers in our room, but adding new blade servers and need some extra help :)

Thanks!
Kylie

]]> Comment on Are there DC circuits in your Data Center? by Wouter Kestelyn http://blog.datacenter-link.com/?p=27#comment-55 Wouter Kestelyn Fri, 20 Jun 2008 16:06:14 +0000 http://blog.datacenter-link.com/?p=27#comment-55 Distributing all the different required chip-level DC-voltages is indeed not feasable because this would incur high currents and a huge amount of copper. But it would be feasable to distribute DC voltage around the datacenter and step it down at rack level. One could for eg. replace the blade chassis rectifiers with DC/DC converter modules. DC/DC is only one conversion, while a typical rectifier module already has two (and that's double!) converter stages; power factor corrector ánd DC/DC. But this is nothing more than the high-voltage DC concept which is in testing phase already. Distributing all the different required chip-level DC-voltages is indeed not feasable because this would incur high currents and a huge amount of copper.
But it would be feasable to distribute DC voltage around the datacenter and step it down at rack level. One could for eg. replace the blade chassis rectifiers with DC/DC converter modules.

DC/DC is only one conversion, while a typical rectifier module already has two (and that’s double!) converter stages; power factor corrector ánd DC/DC.

But this is nothing more than the high-voltage DC concept which is in testing phase already.

]]> Comment on New Guidelines for Datacenters Cooling by Ezio Sturaro http://blog.datacenter-link.com/?p=12#comment-54 Ezio Sturaro Fri, 20 Jun 2008 15:18:37 +0000 http://blog.datacenter-link.com/?p=12#comment-54 Uniflair following these ideas has developed Active Floor that is a flexible solution designed for cooling high density heat loads resulting from the use of modern blade servers and Tera Routers. Integrated within a raised access floor in front of the intake section of the server rack, the Uniflair Active Floor fits exactly into a standard raised access floor featuring 600mm x 600mm panels. The cold air issued by the Close Control units is directly channelled to the source of the heat load thanks to the sophisticated adjustment of the direction of the air flow. The Active Floor creates a high density bubble of air which is maintained at a constant temperature along the whole intake section of the rack (from the lowest to the highest point) guaranteeing operation at the nominal conditions required by the rack manufacturer. The air flow varies according to the heat load detected by the two sensors positioned in the discharge section of the Blade Server. The Active Floor minimises energy absorption thanks to the use of an innovative fan with an electrical commutated motor. The Active Floor may be used both in stand alone applications to slave high density servers in traditional data centers as well as with Close Control perimeter units together with an innovative automatic floor pressurisation system which has been fully tested by Uniflair. It may also be inserted in the Active Floor System for optimum control of the operating conditions in the server rooms. Uniflair's extensive testing of the Active Floor guarantees optimum operation of the equipment for loads of up to 15 kW. Combined with the Cool Pool solution, thermal loads of up to 25 kW for each rack can be managed. Uniflair following these ideas has developed Active Floor that is a flexible solution designed for cooling high density heat loads resulting from the use of modern blade servers and Tera Routers.
Integrated within a raised access floor in front of the intake section of the server rack, the Uniflair Active Floor fits exactly into a standard raised access floor featuring 600mm x 600mm panels. The cold air issued by the Close Control units is directly channelled to the source of the heat load thanks to the sophisticated adjustment of the direction of the air flow. The Active Floor creates a high density bubble of air which is maintained at a constant temperature along the whole intake section of the rack (from the lowest to the highest point) guaranteeing operation at the nominal conditions required by the rack manufacturer. The air flow varies according to the heat load detected by the two sensors positioned in the discharge section of the Blade Server.
The Active Floor minimises energy absorption thanks to the use of an innovative fan with an electrical commutated motor.
The Active Floor may be used both in stand alone applications to slave high density servers in traditional data centers as well as with Close Control perimeter units together with an innovative automatic floor pressurisation system which has been fully tested by Uniflair. It may also be inserted in the Active Floor System for optimum control of the operating conditions in the server rooms.
Uniflair’s extensive testing of the Active Floor guarantees optimum operation of the equipment for loads of up to 15 kW. Combined with the Cool Pool solution, thermal loads of up to 25 kW for each rack can be managed.

]]> Comment on Are there DC circuits in your Data Center? by Damiano Buscemi http://blog.datacenter-link.com/?p=27#comment-53 Damiano Buscemi Fri, 20 Jun 2008 15:16:12 +0000 http://blog.datacenter-link.com/?p=27#comment-53 Wouter, I agree with most of your points. I would like to add something. The possibility to go all around the iles or the racks with all the needed voltages is somehow limited by physical constraints. We, in Socomec UPS, were facing the request of a customer of us asking for a rack DC solution providing +12, +5, .... from the top of the cabinet. Looking at the sum of all the currents we should have been providing, more than 200 A to a large number of +5V cables were needed; a lot of problems to wire such a cabinet and have good safety levels. Starting from a common high voltage (low current) DC bus and then stepping down to the needed voltage with high efficiency DC/DC converters could be the solution. We have a -48 DC Voltage ready from the shelf solution suitable for one single rack datacenter, but this is another topic. Wouter,
I agree with most of your points.
I would like to add something. The possibility to go all around the iles or the racks with all the needed voltages is somehow limited by physical constraints.
We, in Socomec UPS, were facing the request of a customer of us asking for a rack DC solution providing +12, +5, …. from the top of the cabinet.
Looking at the sum of all the currents we should have been providing, more than 200 A to a large number of +5V cables were needed; a lot of problems to wire such a cabinet and have good safety levels.
Starting from a common high voltage (low current) DC bus and then stepping down to the needed voltage with high efficiency DC/DC converters could be the solution.
We have a -48 DC Voltage ready from the shelf solution suitable for one single rack datacenter, but this is another topic.

]]> Comment on Are there DC circuits in your Data Center? by Wouter Kestelyn http://blog.datacenter-link.com/?p=27#comment-19 Wouter Kestelyn Fri, 13 Jun 2008 12:27:29 +0000 http://blog.datacenter-link.com/?p=27#comment-19 In my opinion, the use of direct current is widely underestimated. The better question would be "Where is the use of AC required?". Each and every electronic chip operates on DC-power; so your laptop, cell phone, and every server inside a datacenter operates internally on DC power converted via internal rectifiers. If one would be capable of eliminating all these unnecessary conversion steps, huge gains can be achieved in terms of efficiency. Several studies (egg. Berkeley national lab.) have been performed, or are still going on to show the possible gains (20-30% overall) when adopting direct current for datacenters. Availability of a datacenter could also be improved by the simple reason that the typical energy storage system for backup are batteries, and guess what: they provide DC! Which means no power conversions have to be performed in case of mains outage. To my opinion, concerns about the current interruption problems are also overestimated. Problems with interrupting DC or AC current is in fact almost the same. AC current does pass trough zero at regular times, but almost never at the point you want to or must interrupt. Even worse, the peak current of AC-power is even higher the DC-power if you use the same RMS voltage, which means the arc will be twice as severe in case of AC-current. Even further, the problems with arc-forming in breakers can be easily resolved by a simple free-wheel diode; only possible with DC-power. No arc-forming also implicates less EMI for sensitive IT equipment, with higher availability as consequence. AC-power is for electrical engines, what a server really needs...is direct current. In my opinion, the use of direct current is widely underestimated.
The better question would be “Where is the use of AC required?”.

Each and every electronic chip operates on DC-power; so your laptop, cell phone, and every server inside a datacenter operates internally on DC power converted via internal rectifiers.
If one would be capable of eliminating all these unnecessary conversion steps, huge gains can be achieved in terms of efficiency.
Several studies (egg. Berkeley national lab.) have been performed, or are still going on to show the possible gains (20-30% overall) when adopting direct current for datacenters.

Availability of a datacenter could also be improved by the simple reason that the typical energy storage system for backup are batteries, and guess what: they provide DC! Which means no power conversions have to be performed in case of mains outage.

To my opinion, concerns about the current interruption problems are also overestimated. Problems with interrupting DC or AC current is in fact almost the same. AC current does pass trough zero at regular times, but almost never at the point you want to or must interrupt. Even worse, the peak current of AC-power is even higher the DC-power if you use the same RMS voltage, which means the arc will be twice as severe in case of AC-current. Even further, the problems with arc-forming in breakers can be easily resolved by a simple free-wheel diode; only possible with DC-power. No arc-forming also implicates less EMI for sensitive IT equipment, with higher availability as consequence.

AC-power is for electrical engines, what a server really needs…is direct current.

]]> Comment on New Guidelines for Datacenters Cooling by chuck goolsbee http://blog.datacenter-link.com/?p=12#comment-3 chuck goolsbee Fri, 18 Apr 2008 15:21:47 +0000 http://blog.datacenter-link.com/?p=12#comment-3 <i>the highest part of the rack, typically the area which suffers the most</i> Then why not just leave raised floors behind in the mainframe era where they belong? --chuck the highest part of the rack, typically the area which suffers the most

Then why not just leave raised floors behind in the mainframe era where they belong?

–chuck

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