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  1. #1
    Join Date
    Jun 2006
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    8
    When do you use a bleed type txv vs. a non bleed type?
    any advantage of one over the other?

  2. #2
    Join Date
    Jan 2004
    Location
    Lancaster PA
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    67,875
    A technical question from a TV executive.

    Non bleed will increase SEER by 1/2 a point or so.
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    How many times must one fix something before it is fixed?

  3. #3
    Join Date
    Jun 2006
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    8
    Yup - but unrelated to tv! I understand the improved efficiency, is there a reason to use the bleed or non-bleed or are they interchangeable? Thanks!

  4. #4
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    Apr 2002
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    Dallas, TX
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    You want to use a non-bleed TEV for efficiency. PSC compressors without a hard start kit will require equalization during off cycle to restart. Scroll compressors do not require equalization.

  5. #5
    Join Date
    Sep 2003
    Posts
    1,311
    Unless it is installed correctly (which guys usually don't) a non-bleed TXV can get oil in the equalizer tube and cause the TXV to malfunction.

    With the bleed TXV the installer must be sure to install the bulb BEFORE the equalizer port or the valve will hunt alot.

  6. #6
    Join Date
    Dec 2002
    Location
    Houston,Tx.
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    15,912
    Originally posted by sadlier
    Unless it is installed correctly (which guys usually don't) a non-bleed TXV can get oil in the equalizer tube and cause the TXV to malfunction.
    Does a non bleed have an equalizer tube?
    __________________________________________________ _______________________
    “Experience is a hard teacher because she gives the test first, the lesson afterwards". - Vernon Law

    "Never let success go to your head, and never let failure go to your heart". - Unknown

  7. #7
    Join Date
    Sep 2003
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    1,311
    TXV's can be internal or externally equalized. All externally equalized units have the equalizer tube. Don't go with internally equalized on AC equipment.

  8. #8
    Join Date
    Jul 2000
    Location
    Louisiana , USA
    Posts
    3,280
    Originally posted by melo
    When do you use a bleed type txv vs. a non bleed type?
    any advantage of one over the other?

    This is Turtle.

    The Bleed TXV is good but i like the no bleed TXV for my thoughts on it is everytime the system cuts off it will hold a full load of liquid in the liquid line and is ready to start flowing the second the compressor fires up. it will have 200 psi on the LL right there ready to go. the Bleed TXV and the compressor will have to run about 3 to 8 seconds of time to get the 200+ psi LL pressure to make the TXV open up and start flowing.

    So The Non-Bleed will run about 1 second or less before it starts cooling and gets to the 200+ psi pressure to be cooling right off for it still has the 200 psi pressure on the LL and does not have to take anytime to get up to the 200+ psi to start cooling because it has 200+ psi on it all the time to start with 24 hours a day. also the Non-Bleed will act as a pump down valve to keep the LL pressure up and ready to start cooling.

    So the bleed type will have a equalized pressure between the head and the suction and will have to run about 3 to 8 seconds before it will get the LL pressure up to 200+ psi to start cooling. with this bleed type your running your compressor 3 to 8 seconds with no effect and would cost more to run like this.


    Then a non-Bleed starts cooling 1 second after it starts because head pressure is up already to go and up to speed.

    Then a bleed starts cooling 3 to 8 seconds after it starts. It waste 3 to 8 seconds of run time just getting up to speed in a cycle. so the bleed will cycle 4 times a hours in the operation and then base on 24 hours. Then the Bleed will run the compressor 4.8 minutes to 12.8 minutes of no effect or non-productive run time per day.

    -------------------------------------------------

    4.8 minutes of wasted compressor run time per day or .33% wasted run time of the day with NO EFFECT.

    12.8 min/day of wasted compressor run time or .88% wasted run time of the day with NO-EFFECT.

    ---------------------------------------------------

    So the bleed TXV will cost more than the Non-Bleed to operate in a day.

    TURTLE

    P.S. WOW I got deep here.

  9. #9
    Join Date
    Apr 2002
    Location
    Dallas, TX
    Posts
    2,987
    Originally posted by sadlier
    Unless it is installed correctly (which guys usually don't) a non-bleed TXV can get oil in the equalizer tube and cause the TXV to malfunction.

    With the bleed TXV the installer must be sure to install the bulb BEFORE the equalizer port or the valve will hunt alot.
    sadlier, I think you are confusing an externally equalized TEV with a bleed port TEV (a common mistake). A TEV with 2 connections is an internally equalized TEV. A TEV with 3 connections is an externally equalized TEV.

    Either one of these valve can have a bleed port.

    The location of the equalizer line connection on the suction line has absolutely no relevance to whether the TEV has a bleed port or not. The equalizer has no special function with a TEV having a bleed port.

    [Edited by Andy Schoen on 09-07-2006 at 10:18 PM]

  10. #10
    Join Date
    Apr 2002
    Location
    Dallas, TX
    Posts
    2,987
    Originally posted by turtle

    So the bleed TXV will cost more than the Non-Bleed to operate in a day.

    TURTLE

    P.S. WOW I got deep here.
    That's a fact. Install hard start kits on those PSC recip compressor motors, install non-bleed TEVs, and improve efficiency.

  11. #11
    Join Date
    Dec 2002
    Location
    Houston,Tx.
    Posts
    15,912
    Originally posted by turtle
    So the bleed TXV will cost more than the Non-Bleed to operate in a day.
    TURTLE
    P.S. WOW I got deep here.

    Turtle, if I install A GMC 671 blower on my liquid line will this help my performance any as in bringing the pressures up faster?
    __________________________________________________ _______________________
    “Experience is a hard teacher because she gives the test first, the lesson afterwards". - Vernon Law

    "Never let success go to your head, and never let failure go to your heart". - Unknown

  12. #12
    Join Date
    Jul 2006
    Posts
    613
    if I install A GMC 671 blower on my liquid line will this help my performance any as in bringing the pressures up faster?


    Not sure about that BUTTTT....

    That SB chevy engine will love it)))

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