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  1. #1171
    Join Date
    May 2004
    Location
    Los Angeles, CA
    Posts
    1,560
    Dear Serverroomcooling,

    Regarding your previous post:

    “now way....not starting with the operation heat load again....that's a real dead end.....what I am doing is putting in a challanger that can pump out from 3-5 tons so I can adjust it is I find I really need 3.5 tons. Right now, I have been told that I am getting 1.5 net tons because of the load, out of the full 3 ton trane.....I can't go and demand heat load tests again, it just won't be fun, and I don't have the time…”

    First, I’m not sure who you are addressing with your posted “…not starting with the operational heat load again…”, but if it were me, then I would state that you have yet to determine your heat load based on what you have already posted my friend.

    Second, “you” won’t be able to adjust the new system for 3, 4, or even 5 tons because “if” the system is equipped with hot gas bypass (DBV), then it does so automatically based on it’s commissioned setting.

    Third, who told you were only getting 1.5 net tons from your 3 ton system? This is the first time you have posted this my friend. How did “they” obtain this information, quantified analyses of the system’s operating readings, or just by guessing? This type of quantified statement would require a complete set of operational readings, which has NEVER been performed as far has we here can tell, to be accuarte.

    ???????????????????

    Respectfully Submitted,
    John J. Dalton








  2. #1172
    Join Date
    May 2004
    Location
    Los Angeles, CA
    Posts
    1,560
    Dear Serverroomcooling,

    Ninety-one pages and counting…….will this thread never end…..lol.

    Respectfully Submitted,
    John J. Dalton


  3. #1173
    Join Date
    May 2005
    Posts
    39
    "Name the parts Liebert uses that the other CRAC's couldn't/don't use.

    Is Liebert designing their own motors?
    Compressors?
    Valves?
    Coils?
    Contactors? "

    ========================
    I'd say that the short answer is that Liebert does not design their own components, but that they do specify them conservatively.

    All I can go on is my experience. A NEMA 184T frame motor is almost always 5 HP tops, unless it is installed in one of Liebert's competitors' units. Then it is suddenly 7.5 horsepower (rated as air-over), and you will need gloves to handle it if you don't wait a couple of hours for it to cool down before removing it. Liebert uses mostly Carlyle bolted hermetics, whereas most of their competitors use pots. I have never seen a dual fan scroll with a 7.5 HP motor in a Liebert that had a 1" diameter fan shaft. I have never seen rubbers in Liebert fan bearings. I see it pretty typical for Liebert to use a 30 amp contactor for a compressor that they knew would never draw more than 12 amps. I never see them break two legs of three phase in order to save one pole on a contactor. A 4" driveR with 6.6" driveN sheave will work with two B belts for at least 700 hours before you have fried belts (7.5 HP, 1740 RPM). In the same scenario, I see Liebert using 6" R and 10" N sheaves, and the belts last around 10,000 hours. It all comes back to whether you want to spend your money on good equipment and installation, or on maintenance.

    If the devil is in the details, I'd say that Liebert has done a really good job of covering the details.

    Good reputations are hard won, and easily lost. This is why brand names are so valuable.

    Regards,
    Rotorbar.

  4. #1174
    Join Date
    May 2002
    Posts
    9,564
    Well, if it's high quality components than everyone should be using Riedel instead.

  5. #1175
    Join Date
    Apr 2003
    Location
    the Great Pacific Northwest
    Posts
    607
    Originally posted by john dalton
    Dear Serverroomcooling,

    Something about “chilled water” in a dense server rack just sounds so…….impending to me. Condensation, water leaking, something just doesn’t set right for some reason, oh well, as long as they know what they’re doing…………….or do they?????????

    Respectfully Submitted,
    John J. Dalton
    Interesting note on data center cooling is that at one time one of lieberts main lines in volume was the CSU 3000 (I think thats right ) which was a multi stage chiller that was piped right into the mainframe cabinet with quick connect hose fittings for water cooled heat sinks. Looks like history is repeating itself. I also understand that there were very few problems in general with these systems as far as the water goes. Although piping water around a data room does go against the grain for me too.

  6. #1176
    Join Date
    May 2004
    Location
    Los Angeles, CA
    Posts
    1,560
    Dear hvac-tech-lane,

    I had an old college history professor that use to always say:

    “If you want to know where we’re going, just look at where we’ve been”

    Like the fashion industry, everything comes back around sooner or later it seems. My nineteen year old son has been into overclocking computers for the last few years and water cooled, or even chilled water cooled CPU blocks are extremely commonplace in this field. The CPU performs better, lasts longer, and the heat is not discharged into the server room. But, even with all this, condensation is an extreme problem and must be dealt with or catastrophic results will occur, the chilled water must be maintained above the wet bulb temperature of the surrounding air(server room).

    Based on the above information I would still go with conventional server room cooling technology until the density of the server racks were such that this technology would come into play. In other words, sooner or later we all will be looking at a different way to cool these servers because of this increasing higher density situation.

    In conclusion, as always, we all must be open to new cooling technologies with this particular application, as well as with our other more conventional systems.

    Respectfully Submitted,
    John J. Dalton

  7. #1177
    Join Date
    Nov 2004
    Location
    Hollywood, FL
    Posts
    365
    The liebert arrived today....as soon as I get the electric squared away with my building it will be in....now this thing looks like it'll do the job!!!


  8. #1178
    Join Date
    Jan 2005
    Posts
    604
    Originally posted by serverroomcooling
    The liebert arrived today....as soon as I get the electric squared away with my building it will be in....now this thing looks like it'll do the job!!!

    How about some pictures! I find I don't read text as much as I used to, but love pictures.

  9. #1179
    I am so glad you brought this post back to life, I really missed it.
    Hey cockroach, don't bug me! ©

    www.AskTheDiceman.com

    www.TheColdConspiracy.com

    www.Pennwood-HVAC.Com

    Bring Em Home....

  10. #1180
    and it took ninety one pages to arrive at the solution?


    Liebert shold have been the first thing considered.





  11. #1181
    Join Date
    Nov 2004
    Location
    Hollywood, FL
    Posts
    365
    how do I post pictures on this thread??

    A liebert type system was proposed, but tI got shot down for price

  12. #1182
    Join Date
    Nov 2004
    Location
    Hollywood, FL
    Posts
    365
    I'm putting in a Challanger 3000....there is a Fan unit that is going on my roof as well

  13. #1183
    Join Date
    Nov 2004
    Location
    Hollywood, FL
    Posts
    365
    here is a link to see some pictures

    http://share.shutterfly.com/action/w...8AatmTdk5auXKw

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