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  1. #14
    Join Date
    May 2009
    Location
    The Pas, Manitoba Canada
    Posts
    212
    Had water leaking through the water regulating valve bellows once. refrigerant leaking showed where to look that time. No refrigerant leak at condenser outlet?
    Bernoulis law deals with a lower pressure being created right at the leak caused by the refrigerant flow in the pipe when it's swirling just right.
    Saw a well that needed to be cleaned out once and it was 1 .5 inch tubing with the 1.5 ft long fitting at the bottom with compressed air being fed in the side of the fitting with the air line being pointed up inside the fitting all the air went up and drew water and mud out of the bottom of the well. The air compressor was at 100 psi and the pipe was wide open at both ends
    Last edited by K_Neil; 05-27-2012 at 10:20 AM. Reason: faulty memory

  2. #15
    Join Date
    Dec 2004
    Location
    Chicago area
    Posts
    1,439

    Well

    Osmosis isn't it. It could be osmosis if there were some kind of semi-permeable material being used such as rubber, but copper or steal, I don't really think so.

    Obviously there is a leak in the bundle. Replace the bundle, or find the leak and repair it.

    As far as weight goes, how do you know that you don't have a bunch of water in the recovery tank?

  3. #16
    Join Date
    Aug 2002
    Location
    Sacramento area
    Posts
    69

    Wink Osmotic pressure difference causes the problem

    Google "Examples of osmosis".

    When you read a definition of osmosis, don't stop reading after the first couple of sentences. Keep reading to understand what it means.

    The semi-permeable material in your water cooled refrigeration circuit is a small leak such as a gasket, or the pressed fit of a copper tube inside a shell and tube condenser, or a poor brazed connection that joins the water tubing to the refrigerant tubing (maybe porous from contaminates during brazing).

    The "osmotic pressure" of the water is greater on the 40 psig water side than it is on the 60 psig refrigerant side, when no water is on the refrigerant side, so this greater osmotic pressure wants to force water through this small permeation until the osmotic pressure is equal on both sides.

    Osmosis allows moisture in the soil to travel to the the leaves at the top of a tree.

    When my wife uses perfume in the bathroom and the exhaust fan is on, the pressure is less in the bathroom, but the smell of perfume makes it's way to the next room that has a higher pressure.

    When my wife is baking in the kitchen with the exhaust fan on, the smell of her great cooking permeates other areas in the house that have less pressure.

    I'm not sure if those last two are technical examples of osmosis, or of diffusion, but they are similar. Also similar: how about absorption refrigeration? Ammonia or lithium bromide will absorb water with no pressure difference.

    You need to think of the "osmotic pressure" being greater rather than thinking of the psig of the different fluids.

    By the way, I'm an "old instructor" but in this trade I'm always learning, so I feel like an uhPrintUs at times.
    I'm still learning this trade.

  4. #17
    Join Date
    Nov 2005
    Location
    California
    Posts
    23
    Sounds like your a pretty smart guy uhPrintUs.

  5. #18
    Join Date
    May 2006
    Location
    Amory Mississippi
    Posts
    998
    Quote Originally Posted by crymtide View Post
    If it's leaking it's leaking and the scientific principle behind the leak path isn't the big issue here. If you have found water several times as you stated why isn't as important as where. In a sealed water cooled system as you find on an ac system providing cooling on yachts with a jacketed condenser any water in refrigerant lines is a leak between tubing systems. In larger systems with gasketed heads the leak could be in the gasket or gasket seating surfaces and torque of head bolts would just be one of many reasons for leaking. It's your system and instead of struggling with why find the leak and worry about why later. Scientific principles are just best guesses given with data provided and as such are indicators and not irrefutable answers.
    X2

    Reair or replace the heat exchanger. move on with your life. capillary action, osmosis, venturi effect. Fix the leak and it will go away.

  6. #19
    Join Date
    Feb 2010
    Location
    In a boiler room
    Posts
    7,050
    What most likely happened is that when the leak first formed, no water entered the refrigerant.

    However as the refer leaked out into the water it finally reached a point where the pressures where equal, and then the water could easily get into the refer.

  7. #20
    Join Date
    Jun 2012
    Location
    Northern NV
    Posts
    154
    I believe that the reason the low side water makes it into the high side refrigerant is the diffusion principle. I do know that for gasses that even a flow of gasses cannot stop the "upwind" diffusion of another gas or gaseous molecule from "swimming upstream" due to the concentration difference and the desire of all thing to balance out.

    Diffusion is why you smell cigarette smoke in a separate AH non-smoking zone even with a pressure gradient specifically there to minimize the smoke's migration.

  8. #21
    Join Date
    Aug 2011
    Location
    Chicago
    Posts
    51
    Evap pressure can be lower at times than water side with compressor running at lower load, unloading or low on charge. Bernulli's principle is as simple to explain as adding Miracle grow in your garden. jar at 0psig garden hose running water past at 40psig creates a lower than 0psig pressure and pulls Miracle grow from bottle and mixes with garden hose H2O

  9. #22
    Join Date
    Jul 2012
    Location
    Richland, WA
    Posts
    248
    I had to replace a water cooled condensor coil on Multiplex's at one of the 16 McDonald's stores cause the condensor coil had a leak in it. Never could figure out why the leak happened, cared about fixing the leak more then why.
    Last edited by caheiman30; 08-09-2012 at 07:58 PM. Reason: typo

  10. #23
    Join Date
    Jul 2012
    Location
    Western KY
    Posts
    1,221
    It's magic. Fix the leak kill the magic.

  11. #24
    Join Date
    Oct 2008
    Location
    mid-Tennessee
    Posts
    709
    Quote Originally Posted by Six View Post
    Still waiting for a explanation to how Bernoulis principle has amything to do with a busted condensor.
    My best explanation would be in understanding the operation of an "eductor". A pinhole leak in the refrigerant line forms a crude eductor, allowing it's venturi effect to draw in the water.

    An example of the common use of an eductor is chemical injection in a pressure washer. Although the chemical sits in a bottle at atmospheric pressure, a designated tube can draw the chemical from that bottle and be injected into the high pressure water stream. The vacuum which allows this is through a componemt called an eductor.

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