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Conference ssag::ask_ssag

Title:Ask the Storage Architecture Group
Notice:Check out our web page at http://www-starch.shr.dec.com
Moderator:SSAG::TERZAN
Created:Wed Oct 15 1986
Last Modified:Fri Jun 06 1997
Last Successful Update:Fri Jun 06 1997
Number of topics:6756
Total number of notes:25276

6602.0. "Conflict in SW800 and Turbolaser Airflow design" by JOBURG::HARRIS () Mon Apr 21 1997 03:44

Cross posted in turbolaser


AIRFLOW : Storageworks versus TURBOLASER

The design of the Storageworks SW800 is
Air in: Front and Rear
Warm Air out: Top and bottom Rear.

The design of the TURBOLASER is
Air in: Top and Bottom
Warm air out: Front and Rear.


This is strange, or did our design teams not have the same 
crititeria when designing the the enclosures?

Yes, This issue was raised by my client as well.

Can future cabinets be designed with our systems in mind.

Regards Ivan


T.RTitleUserPersonal
Name
DateLines
6602.1KERNEL::LOANEComfortably numb!!Mon Apr 21 1997 05:3110
>The design of the Storageworks SW800 is
>Air in: Front and Rear
>Warm Air out: Top and bottom Rear.

    The  airflow  (with  the  exhaust  fans  at  the bottom) is aimed at 
    reducing the air  pressure  inside  the  plenum  between  the  BA35x 
    shelves.  This  gives  a greater differential pressure for the shelf 
    fans to work with, and hence makes them  more  efficient  (or  shift 
    more  warm  air...whatever your view!!). In other words, the airflow 
    is specific to the implementation.
6602.2SW800 versus AS8400JOBURG::HARRISMon Apr 21 1997 05:4117
    re: .1
    Hello Chris,
    
    I agree..however the conflict is with Sw800 versus AS8400. 
    We now have 10 x AS8400, 12 x Sw800, 8 X Laser7000 and a bunch of other
    AXP,vax small, gigaswitches and other 3rd party equipment. 
    
    Movement of the warm air in this computer has become an issue due to
    bad aircon and airflow design. 
    
    It would have been more practical to have kept to some standard all
    cabs either in at the bottom and top or all out at the bottom and top.
    
    Keep well, 
    Regards
    Ivan
    
6602.3HOUNDD::BASSETTBillTue Apr 22 1997 14:0941
    Hi Ivan,
    
     To answer your initial question - NO, the products were developed
    pretty much independently.  The looks and the overall formfactor were
    coordinated (I believe the cabinets themselves - the framework/casters
    - were designed by the same group.)  However Storage and the Alpha
    group were in different parts of the company.  We are now all part of
    the SBU, so there may be more commonality.  But maybe not, since the
    design requirements for storage and CPU's are often different.  
    
     Up until StorageWorks, our storage products that rack mounted had one
    very common feature - the air entered through the front and exited out
    the back.  The drives such as RL0x's, RA8x's, and RA60 were full width,
    full depth and full height (10�").  Then we had the RA9x/SA7x
    generation (� width, full depth, and full height) that also cooled front 
    to back.  The DSSI equivalents - SF7x and SF3x - were also front to
    rear, as were the Tx8x7 family of tape loaders.
     Most standalone storage (I can't thick of an exception, but there is
    probably one out there!) such as RM0x's, RP0x's, and HSCxx's were front
    to rear.  
     [If you remember, most of the older products sat side by side.  The air 
    had to go either front to back or bottom to top.]
    
     But when we switched to the 3�" disk, all the form factors changed. 
    We could now fit drives into enclosures that were only half depth.  To
    maximize Megabyte per square foot (now Gigabyte/ft�) we installed
    shelves front and rear.  Since we didn't want preheated air in the
    intake of the rear shelves, the air flow path was changed to front to 
    top and rear to top.  (With the natural rising movement of hot air it 
    made sense to exhaust up.  Also there is NOT enough room underneath the
    SW800 to exhaust there - unless in a computer room with a raised floor.
    The SW800 is not limited to that environment.  The flushing fans add to 
    the natural convection.)  Later with the introduction of 7200 RPM drives 
    we had to add the bottom fan tray to cool these "hotter" SBB's.
    
     What I cannot answer is why the Alpha exhausts to the front.  I'm sure
    there were good reasons.  
    
     Hope that helps....
    
    				Bill