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  1. #1
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    R134a,R407c,R22 Comparison


    I am a contractor operating in Saudi Arabia and need to know equipment cost impact for the same capacity.

    1-Screw Chillers air cooled using R134a versus R407c

    2-Package Units using R 22 versus R 134a

    3-Package Units using R 22 versus R 407c

    4-DX Package Units using R 134a versus R 407c

    Which of the options with the matching Refrigerent apply best for high Ambient temperatures + High Humidity O.A. Temp..

    Same question but for high ambient + low wet bulb O.A. temp.

    Which of the above will be the industry standard in the future and why.

    Appreciate your professional input.

    Chahine999



  2. #2
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    Re: R134a,R407c,R22 Comparison

    All air cooled equipment, either chillers or conditioners, for middle east is recommended to be R134a for reducing the service pressure.
    The industry standard in the future, for EU, will not be in F-gas. USA and USA-friendly countries, like UAE, will probably keep polluting the environment with R22 until dawn of the humankind, though major chiller manufacturers are sponsoring R134a.
    Humidity has no influence on the choice of refrigerant, because air cooled condensers work based on dry bulb, not on wet bulb.
    DX systems installed in humid rooms are not recommended (by me). I prefer to suggest clients for chilled water coil systems, in these cases, in order to prevent too much condensate or risk of freezing on the coil surface.

  3. #3
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    Re: R134a,R407c,R22 Comparison

    Quote Originally Posted by NoNickName
    DX systems installed in humid rooms are not recommended (by me). I prefer to suggest clients for chilled water coil systems, in these cases, in order to prevent too much condensate or risk of freezing on the coil surface.
    How does the volume of condensate change if the coil is DX or chilled water?

    If both are at the same temperature and operating at the same conditions, I suspect the volume of condensate will be similar.

    USA and USA-friendly countries, like UAE, will probably keep polluting the environment with R22 until dawn of the humankind
    I don't think this was too helpful or necessary.
    Last edited by US Iceman; 05-04-2006 at 02:27 PM. Reason: text

  4. #4
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    Re: R134a,R407c,R22 Comparison

    Quote Originally Posted by US Iceman

    If both are at the same temperature and operating at the same conditions, I suspect the volume of condensate will be similar.
    Yes, but in a close control application, a discharge probe can be installed. As soon as the saturation of supply air approaches, the regulating valve on the chilled water can be progressively closed in order to prevent too much condensate, or any at all, in all-sensible applications.
    This cannot be done with DX, unless a hotgas bypass is installed, which is defitely a curse against efficiency.

    Quote Originally Posted by US Iceman
    I don't think this was too helpful or necessary.
    It wasn't actually. But I love to express my point of view.

  5. #5
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    Re: R134a,R407c,R22 Comparison

    The industry standard in the future, for EU, will not be in F-gas. USA and USA-friendly countries, like UAE, will probably keep polluting the environment with R22 until dawn of the humankind, though major chiller manufacturers are sponsoring R134a.
    F-gas? 134a is a fluorocarbon as are all the other HFC's mandated by the Montreal Protocol and now challenged by the Kyoto treaty.

    The US has specific guidelines for the complete phaseout of R22 and the cost of the refrigerant is rising monthly now as all other refrigerants remain stable. DuPont and others are touting new hfc replacements that can be dropped in which will make conversions to existing equipment much less expensive and practicle. R410a is all but mandated with the new SEER 13 regulation put in place this year for all residential new equipment sales. Major supermarkets have switched from R22 and many are converting them to R404a or R507, which are now considered undesirable because of the Global Warming Potential.

    We are moving perhaps more slowly than EU, but also are looking ahead to Co2 subcritical applications and transcritical applications and most importantly systems that limit the amount of refrigerant exposed to the environment. R22 will be mostly a memory in another decade. It was a phaseout arrived through our participation in the Monreal Protocol, in which the EU participated and agreed to. And profitability and cost issues dictate this phaseout as the price rises in a natural way as production is phased out.

    Regardless, the dawn of humankind was a very long time ago and there wasn't any R22 being used back then.

  6. #6
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    Re: R134a,R407c,R22 Comparison

    Quote Originally Posted by Dan
    Regardless, the dawn of humankind was a very long time ago and there wasn't any R22 being used back then.
    More than likely they were using methane Dan.

  7. #7
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    Re: R134a,R407c,R22 Comparison

    It was meant to be "doom of humankind".
    Ok, guys, we made our point clear.
    And yes, I know 134a is an F-gas. My opinion is that R134a and R410 are sponsored by the lobby of producers, and there's no obvious and overwhelming technical reason to use either of them.

  8. #8
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    Smile Re: R134a,R407c,R22 Comparison

    Thanks guys, your responses were very helpful and informative.

  9. #9
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    Re: R134a,R407c,R22 Comparison

    Im just new here in RE, and i have some questions regarding R407C and i hope someone could help me.

    We are experiencing some problem with our 10-ton split type air-conditioning unit serving electrical room. The condenser is located near a furnace and the surrounding temperature around the condensing unit is around 45 to 55 degrees celsius. With the refrigerant R407C, the discharge pressure of the compressor is reaching 26 bars and the unit is tripping on a high pressure cut-off. We are located here in Doha, Qatar, what will be the gain if we switch from R407C to R134A? Will it help? Does using R407C refrigerant on such high ambient temperature has something to do with the tripping? Is it advisable to use R407C here in Qatar?

  10. #10
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    Re: R134a,R407c,R22 Comparison

    Repost this as a new thread, otherwise nobody will read this because you're replying (!!) to a post which is 4 yeras old
    It's better to keep your mouth shut and give the impression that you're stupid than to open it and remove all doubt.

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