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  1. #1
    Join Date
    Jun 2005
    Posts
    66
    Is there such a thing as different fan blade pitches for condensers?

    Air is being pushed out the sides of the top instead of directly out of the top of the unit. In other words, you can put you hand directly over the top of the unit and not feel anything. All the air is coming out around the sides at the top.

    Is it a 1994 Resco 3 Ton unit.

    I am not the original owner of this unit and my thoughts are that someone along the line maybe put on the wrong blade.



  2. #2
    Join Date
    Dec 2002
    Location
    Houston,Tx.
    Posts
    16,113
    It is possible the unit had a fan shroud in it and someone took it out and did not put it back after motor change seen this before lots of times, matter fact just Friday on a call saw this on a old Trane XL900, there will be screw holes in the top usually were the shroud was mounted in.
    __________________________________________________ _______________________
    “Experience is a hard teacher because she gives the test first, the lesson afterwards". - Vernon Law

    "Never let success go to your head, and never let failure go to your heart". - Unknown

  3. #3
    Join Date
    Sep 2004
    Location
    Glendale AZ
    Posts
    299
    Yes ,there are different pitches on blades. The wrong pitch can and will cause pre-mature motor failure (not enough air over the motor) Too much pitch-- over-amping of the motor. That's just what can happen to the motor. The lack of air getting pulled through the condensor(not enough pitch) will cause other problems.
    The bitterness of poor quality remains long after the sweetness of low price has gone.

  4. #4
    Join Date
    Jun 2005
    Posts
    66
    Is there a guide or reference to determine what should be on there?

  5. #5
    Join Date
    Mar 2004
    Location
    Grottoes VA
    Posts
    5,856
    A dirty condensor coil will also cause this. I would start there first.
    Karst means cave. So, I search for caves.

  6. #6
    Join Date
    May 2000
    Location
    Indianapolis, IN, USA
    Posts
    34,473
    I've seen that before on the Carrier cubes, even with the original fan blade in place. Not sure if you can stop it by playing with the blade on the shaft. The venturi ring is a part of the top so that's not it. Most of the air is coming though the coil but instead of blowing up, it blows out the sides and can recirculate. At 11 years, you're doing good - you don't have much life left in that heap!

  7. #7
    Join Date
    Sep 2002
    Location
    South Dakota
    Posts
    6,579


    We manufacturer some of the same units in both 50 and 60 hertz. Some of our 50 hz condenser fan motors must have a different pitch blade in order to move the right amount of air without overheating the condenser fan motors.


  8. #8
    Join Date
    Dec 2002
    Posts
    174

    fan blades are cheap...

    ...after checking for shroud and clean coils change that sucker out

  9. #9
    Join Date
    Dec 2002
    Location
    Houston,Tx.
    Posts
    16,113
    I bet someone installed the wrong rotation motor and it's running backwards he said it's pushing the air out the side.
    __________________________________________________ _______________________
    “Experience is a hard teacher because she gives the test first, the lesson afterwards". - Vernon Law

    "Never let success go to your head, and never let failure go to your heart". - Unknown

  10. #10
    Join Date
    Jun 2001
    Posts
    3,916
    Originally posted by karsthuntr
    A dirty condensor coil will also cause this. I would start there first.
    I agree with ^ and also check and make sure that your fan blade is above or "into" the shroud at least 1 ".

  11. #11
    Join Date
    Jun 2004
    Location
    Dallas
    Posts
    179
    Originally posted by mrbillpro
    I bet someone installed the wrong rotation motor and it's running backwards he said it's pushing the air out the side.
    Good thinking, but he did specifically say "the sides of the top"

    to me, that means he expects it to go straight up, which will never really happen. My old ducane is the exact same way- and it works fine.

    My big green trane doesn't blow air out the top at all- it comes out the sides "near" the top.

    Don't try to "fix it". It's not broke.

    My ASSumption is that aw has just bought this house and is checking over everything with a fine-tooth-comb. It's good, but this is NOT a problem.

    Don't worry about it if you are comfortable.

    [Edited by old yeller on 06-21-2005 at 10:55 AM]

  12. #12
    Join Date
    Feb 2005
    Posts
    344

    fan/shroud

    aw,

    Is it cooling?

    My experience has been that the blade and shroud relative position may be incorrect. Moving the blade up and down on the motor shaft changes this relationship.

    Trial and error may be your only recourse. Then again, the airflow may be correct.



    Good luck...



  13. #13
    Join Date
    Jun 2005
    Posts
    66
    The unit is "cooling" so to speak..I think I have other issues such as heat gain/air loss in the house. Thermostat will not stay below 77 in the afternoon. Split between supply and return in 14-15 at the furthest supply duct. I have metal ductwork in the attic so taking a reading near the coil is difficult.

    The unit will run for 11 out of 24 hours. This is an older house built int 1973...with little attic insulation.

    There is no shroud so to speak and no indication there ever was one.


    Thanks for the help everyone

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