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Thread: not cooling

  1. #1
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    not cooling

    I recently had my air handler replaced and added 2 ducts for extra square footage. But now only have a temp split of 10 to 11 degrees. This is not keeping up well. the air handler is a luxaire 3 ton ap36bx21b with a metering device installed for r22 and r407c. It is connected to a rheem 2 ton condenser that was built in 1997 with what appears to be a 3/8 and 5/8 line set. The air handler says it will run r407c , r410a , or r22. My question is what would it take to change the condenser unit to a 2.5 ton 16 seer unit and would i get the temperature split needed. I am cooling 1275 square feet in the heat and humidity of louisiana

  2. #2
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    You need a pro to assess your situation. You can't just upsize the system willy-nilly.

  3. #3
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    not cooling

    Quote Originally Posted by CircusEnvy View Post
    You need a pro to assess your situation. You can't just upsize the system willy-nilly.
    That is why i posted my question to this professional site

  4. #4
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    You first must find out why your current unit isn’t cooling. What does the installer have to say about the poor performance?
    You don’t just go one size bigger just because. And equipment isn’t sized via square footage.
    ďI havenít failed. Iíve just found 10,000 ways that wonít work.Ē - Thomas Edison

    ďItís not whether you get knocked down, itís whether you get up.Ē - Vince Lombardi

    "In this house we obey the laws of thermodynamics" - Homer Simpson

  5. #5
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    not cooling well

    Quote Originally Posted by rider77 View Post
    You first must find out why your current unit isnít cooling. What does the installer have to say about the poor performance?
    You donít just go one size bigger just because. And equipment isnít sized via square footage.
    Had freon checked it checked good, was told my 2 ton condenser would not keep up with the 3 ton air handler. Air temp at return air 71 degrees air temp at farthest vent 61 degrees. Out side temp 88 . Thermostat set at 71

  6. #6
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    To answer your question yes the airhandler most likely will be good with a 2.5 ton condenser but the metering device, ducts, airflow, etc all need to be addressed by the tech.

  7. #7
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    Gotta agree that it sounds like your current unit needs to be assessed more thoroughly. It may not be bad news.

    To bring a perfectly working 12-13 SEER system to 16 SEER would likely involve changing out your outdoor unit, but also would involve changes to your indoor unit as well. Iíd venture to say that returns and supplies would need to be sealed assuming all the duct is sufficient and installed properly.

    There are some assessments that can be done to allow HVAC contractors to know beyond all doubt exactly how much cooling (and heating in the winter) each room requires. This in turn tells them EXACTLY how big and how many duct returns and supplies are needed along with the total unit AC unit size needed.

    Right size is key in hot humid environments like yours. Too much AC the unit doesnít run long enough to remove humidity. Too little AC and the dang thing runs all day eating up your $ in elect without being able to keep up.

    A really useful assessment is the Manual J, and most techs worth their salt know what that is and can show you what you need and where you need it. They can also compare what your systemís doing right now to figure out your options to get it where it needs to be depending on your budget.

    Good luck

  8. #8
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    Thanks for your reply, my inside unit is 6 months old a 3 ton luxaire 1200 cfm that will run r22 with a metering device installed or 407 , or 410. just trying to fiqure out what i may be up against so i don't get reamed. My outside is a 1997 2 ton rheem. The 2 ton did good untill i added 325 square feet to be cooled and added two vents. The inside was changed because it was going out. I am looking at going to a 2.5 ton outside unit 16 seer . Any thoughts?

  9. #9
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    Your in one of the more humid areas of the country. Dehumidification is very important. To do so requires a system that’s sized correctly for the load.
    Your contractor should be doing a load calculation to determine what’s needed as far as size.
    You could upsize to a bigger condenser and wind up with the exact same problem you have now.
    If you replaced the air handler and now are replacing the condenser, you may as well have replaced the whole thing with an AHRI matched system.
    ďI havenít failed. Iíve just found 10,000 ways that wonít work.Ē - Thomas Edison

    ďItís not whether you get knocked down, itís whether you get up.Ē - Vince Lombardi

    "In this house we obey the laws of thermodynamics" - Homer Simpson

  10. #10
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    Thread Starter
    Thank you

  11. #11
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    Well, you certainly got a good life out of the Rheem condensing unit.

    To get to 16 SEER will require a new, closely compatible outdoor unit AND it will require some changes to your recently changed indoor unit also. To achieve 16 SEER you will need to have your unit fitted with a metering device that matches refrigerant type and your system components to dynamically regulate refrigerant flow. A new coil such as yours should be no problem.

    You have options. But without heatload numbers based on your reconfigured living space, youíre guessing.

    Also, consider that R22 systems and R410a systems tend to operate a little differently relative to sizing in my experience. A good tech will advise you on those choices, along with cost differences of the various refrigerants too.

  12. #12
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    Quote Originally Posted by lost in louisia View Post
    Thank you
    I wish you luck in getting your issues solved. Hopefully your contractor actually knows how to troubleshoot, and has the tools necessary to do so.
    I’m convinced your current system isn’t working correctly.
    Figuring out why involves a lot more then looking at pressures on a gauge and declaring everything is ok. This isn’t like filling a tire with air to X psi.
    ďI havenít failed. Iíve just found 10,000 ways that wonít work.Ē - Thomas Edison

    ďItís not whether you get knocked down, itís whether you get up.Ē - Vince Lombardi

    "In this house we obey the laws of thermodynamics" - Homer Simpson

  13. #13
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    Quote Originally Posted by lost in louisia View Post
    Had freon checked it checked good, was told my 2 ton condenser would not keep up with the 3 ton air handler. Air temp at return air 71 degrees air temp at farthest vent 61 degrees. Out side temp 88 . Thermostat set at 71
    Sounds like you have a person that does NOT know what he is doing!!!!

    Can't say freon is "good" if airflow is not correct.

    Saying 2 ton condenser won't keep up with 3 ton air handler is showing your "guy" does not understand how to properly set up equipment or follow instructions in the provided manuals.

    You need to find someone else. Contact neighbors, friends, coworkers or even the Locator feature on this site. You need an onsite evaluation, not an internet assessment. Even with what would seem to be a spot on internet assessment, on site visit is a must!!
    The Food Stamp Program, administered by the U.S. Department of Agriculture, is proud to be distributing the greatest amount of free meals and stamps EVER.
    Meanwhile, the National Park Service, administered by the U.S. Department of the Interior, asks us to "Please Do Not Feed the Animals". Their stated reason for this policy "... the animals become dependent on handouts and will not learn to take care of themselves."
    from an excerpt by Paul Jacob in Sun City, AZ

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