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Thread: 449A

  1. #1
    Join Date
    Jun 2019
    Posts
    6
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    449A

    Hi guys. So the units I mostly work on will be changing to 449a from 404a soon. In some of the country's I work in 449a is simply not available. If the unit comes out and is working well just leave it alone but let’s say it has an issue that results in the system being opened. After the system is corrected and time to re-charge I won’t be able to get any 449a so I am thinking 404a will be my best option. See in south East Asia 404a is considered a new refrigerant. Ok so if I grab the 404a and charge the system the oil is the same POE. I have been checking as best I can and the compressors will run with either 404a or 449a so that should be ok. I may need to make a few small changes to the expansion valve setting but my pressure temp chart will tell me that. Am I missing anything?

    • Tecumseh are recommending a charge of 449a will be 5-10% more that with 404a. So if I work this back a charge of 404a would be 5-10% lower that the 449a charge in the system?
    • The 449a system has a discharge temp valve fitted. (drops a little liquid in to the suction to control the temp) I am thinking A) don’t worry about the valve as 404A will have a lower discharge temp and will likely not open the valve and in the future should 449A be used the valve is already there B) Cut the valve out of the system.

  2. #2
    Join Date
    Mar 2008
    Location
    kansas
    Posts
    1,770
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    I would leave the desuperheating valve or demand cooling in. At 100f your looking at 10psi difference you don’t say if your low or medium temp, but I would keep in as insurance. I think in the states 404 is scheduled in the next 15yrs as phase out date, bet it’s even longer overseas. I say turn it into rocket science when it don’t work
    Honeywell you can buy better but you cant pay more

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  3. #3
    Join Date
    Feb 2010
    Location
    In a machine room
    Posts
    8,166
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    Yes, you will be fine going back to 404a. Just check superheat and adjust valves as needed. Maybe by the time 404a is phased out in your area 449 will be available.

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