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  1. #14
    Join Date
    Jan 2005
    Posts
    8
    The liquid line was replaced today (the original copper pipe was undersized) and a TXV valve fitted in the roof next to the coils.

    The unit is filled with R22.

    Forgive me if my explanations sound pathetic, I'm no a/c expert, and I only have basic knowledge of this stuff (although at times I belive the "techs" know about as much as I do )

    I will correct my first post here, the tech installed an accurator to the system the first time around, it did not have a TXV installed until today.

    Today, after the system was turned on after installing the pipe and valve, the techs filled the system with R22. They filled it until the sight glass was clear (yeah I now know this is wrong, I just read another thread here). The suction pipe inside the outdoor condensor was still starting to frost after a short time, so a tech went in the ceiling to adjust the TXV. Now I don't know how to read or understand a vacuum gauge reading, but one tech at the condensor unit was reading the temps to the guys upstairs adjusting the TXV. It started at about -12 degrees C (10 degrees F) and they adjusted it to between -5 and -6 degrees C (23 - 21 degrees F). The temperature coming out of the air vents was 12.5 degrees C (54 degrees F). Inside temp according to the thermostat was 24C (75F) and outside temp was about the same. After the techs adjusted the TXV, the suction pipe inside the condensor did not frost up.

    Well, about 1 hr after the techs left, and the unit had been running, the suction line again freezed up almost as bad as it had been before ! As usual, the inside temp stays at around 23 -24C (73 - 75F).

    I've thrown my hands up in the air, I'm totally confused. The techs said that the coils are clean and that "this was not the problem anyway".

  2. #15
    Join Date
    Aug 2004
    Location
    North Richland Hills, Texas
    Posts
    14,914
    [QUOTE]Originally posted by jacob perkins
    Originally posted by losiho
    1 watt=3.41 btu
    19 kilowatt=64790btu
    Duh! I knew that, just am not used to thinking in KW for cooling, thanks.

    Surely a "square" in a country that uses the metric system isn't the same as a "square" here is it?



    If more government is the answer, then it's a really stupid question.

  3. #16
    Join Date
    Oct 2004
    Posts
    3,400
    Originally posted by losiho
    a) The unit is overcharged with refrigerant.


    Not likely, as more refrigerant RAISES the temperature of the coil.
    If anything, it could be undercharged.
    This is NOT the only problem, and modifying the charge will NOT resolve the problem.

    Perhaps both repairmen are incompetent, and are not sure what the correct amount of refrigerant the unit requires.

    Apparently self-evident. Replace them.

    b) There are not enough return air grills in the house for the unit. Less likely, imo, as the unit cools adequately unless the pipe is frozen, as described above.


    This is like saying "It works great until it quits. So it must not have a problem? Right?"

    What do you think CAUSES the frozen pipe?

    This is a MOST likely contributor, as airflow dictates how much heat reaches the refrigerant.

    Airflow is CERTAINLY VERY HIGH on the list of things that MUST BE VERIFIED.
    Simply visually inspecting a coil does not prove it is clean. Pay somebody to take it out & CLEAN it.
    Has anybody actually measured the airflow?
    I don't mean hold your hand in front of the grill.
    I mean MEASURED.
    Cubic Feet Per Minute (CFM), or liters per second?

    The indoor FAN may be inadequate, too. Is it clean?

    c) The non-genuine indoor coils are incompatible with the Pioneer outside unit.

    This is a possibility that must be ruled out. I have no way to do that from here. Find a competent contractor. Contact the manufacturer, if need be. Replace it, if necessary.
    If it is incompatable, it is a sizing issue.

    d) The whole compressor and outdoor unit are screwed, and need to be taken out the ocean and attached to a anchor and chain
    THE PROBLEM IS NOT IN THE OUTDOOR UNIT.
    Unless it is a sizing issue.
    It is suffering, and may be dying, but the indoor section, plus ductwork, is where the problem lies.
    I cannot imagine that you are in such a remote part of the world that there are no competent individuals available.

    Get off your wallet and pay somebody to do it right.


    [Edited by bwal2 on 02-11-2005 at 09:05 AM]

  4. #17
    Join Date
    Jan 2005
    Posts
    8
    To all the people who suggest a lack of airflow or dirty coils, could they please try to give an explanation as to why the system will work perfectly without freezing on some days, and others it will freezing the suction pipe to a block of ice and not cool at all ? There is no consistent pattern to its operation - there have been really hot days where the a/c has worked perfectly and will not freeze at all, and other milder days where it will freeze totally and not cool.

    I'm not trying to be a smarty pants or question anyone's knowledge, just trying to help you (hopefully) help me with my problem !

  5. #18
    Join Date
    Jul 2002
    Location
    Zelienople, Pa
    Posts
    2,965
    Maybe you have a dingo stuck in the accumulator tension bearings?

    LOL!
    How tall are you Private???!!!!

  6. #19
    Join Date
    Dec 2004
    Posts
    200
    maybe you shouldnt run the a/c when its only 75 degrees out,,,you shouldnt need it any way,,my answer is not enough load

  7. #20
    Join Date
    Oct 2004
    Posts
    3,400
    Originally posted by losiho
    To all the people who suggest a lack of airflow or dirty coils, could they please try to give an explanation as to why the system will work perfectly without freezing on some days, and others it will freezing the suction pipe to a block of ice and not cool at all ? There is no consistent pattern to its operation - there have been really hot days where the a/c has worked perfectly and will not freeze at all, and other milder days where it will freeze totally and not cool.

    I'm not trying to be a smarty pants or question anyone's knowledge, just trying to help you (hopefully) help me with my problem !
    The load that your air conditioner must move is heat.
    Heat flows toward cooler objects.
    The indoor coil is, by design, cooler than the air that passes over it.
    It is also designed to remove water from the air.
    The indoor coil must run cool, but not cool enough to form ice from that water, because ice will restrict airflow.
    Airflow is critical.

    The conditioner can't condition something it doesn't touch.

    Air conditioners, unlike food storage equipment, are designed to NEVER freeze up. This is done, among other things, by controlling the boiling point of the refrigerant. Defrost is expensive.
    The temperature of the coil is directly related to the heat contained in the air.
    Not just the temperature of the air, but the total heat, taking into account that water vapor contained in air, also contains heat.
    On a cool day, the air is cooler (less heat).
    There is simply not enough heat in the air, on a cool day, to keep the coil above the freezing point of water.

    Normally, an air conditioner is not run on cool days, so extra engineering & controls are not necessary.

    Yours is not working properly, so the temperature does not have to be very cool to send the indoor coil & connecting piping below freezing.

    Which end of the island are you on?

  8. #21
    Join Date
    Dec 2004
    Posts
    200
    thanks bwal,,,thats what i was trying to say

  9. #22
    Join Date
    Jan 2005
    Posts
    8
    By a "cool day", I mean a temp between 25 - 30 degrees C (77 - 86 F). I'm from Melbourne Australia (no dingos here ). Those sort of temps are mild for summer. A "hot" day is anything over 36 degrees C (97F).

    As for not using the a/c on these milder days, sometimes it's not an option. The Australian sun is hotter than in any other country I've experienced, and in a home with a lot of windows, the inside of the house will get hot and stuffy even when it's relatively mild outside.

  10. #23
    Join Date
    Dec 2004
    Posts
    200
    i think you may need a new house,,when you get the new house and a/c make sure the system is charged properly and make sure there is enough airflow across the evaporator coil

  11. #24
    Join Date
    Sep 2002
    Posts
    2,727
    Air out 54 room temp 75 take readings at unit if same or greater difference unit is not moving enough air.

  12. #25
    Join Date
    Oct 2004
    Posts
    3,400
    Originally posted by filterchanger
    thanks bwal,,,thats what i was trying to say
    It's easy for me.
    I get to repeat it every day to a room full of wannabes.

  13. #26
    OK, Here is your answer and it is the correct one. You have a restricted system probably at or very near to the metering device You could spend some time trying to resolve it but what you really need is a good repairman to get a look at it.

    Hope this helps,

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