Page 1 of 3 123 LastLast
Results 1 to 13 of 34
  1. #1
    Join Date
    Aug 2011
    Posts
    19

    Fan running the wrong direction

    I had an HVAC tech out that said that my fan had been running in the wrong direction. I have been having problems with my A/C all summer (Sometimes blowing out warm air, Sometimes running continuously without being able to satisfy cooling conditions and having insanely high electric bills) and I'm wondering if the fan running the wrong direction for the last two months could have been the cause of this.
    So what sort of damage can be done by a fan that has been running in the wrong direction for 2 months? Can if cause the things that I've described? What sort of damage can that do to the unit as a whole??
    Thanks!

  2. #2
    Join Date
    Nov 2006
    Location
    Southeastern Pa
    Posts
    18,533
    Why did you not have the tech correct the problem?
    [Avatar photo from a Florida training accident. Everyone walked away.]
    2 Tim 3:16-17

    RSES CMS, HVAC Electrical Specialist

    AOP Forum Rules:







  3. #3
    Join Date
    Aug 2011
    Posts
    19
    He said that he did fix it, however, I was not there when the maintenance was done and I asked him to leave me a detailed report and all he said was "fan was spinning wrong direction, good now" - But if it had been running in the wrong direction for 2 months couldn't that have done some damage to the system?? I don't even know what he did to fix it.

    My excessively high electric bills in relation to an apartment that wouldn't get below 75 degrees is what prompted my concern.

    Could that have been what caused it??

  4. #4
    Join Date
    Nov 2000
    Location
    Eastern PA
    Posts
    68,944
    Blowers don't just up and decide to run backwards. What was done to the blower motor that caused it to run backwards?

    With the design of a blower wheel, running backwards will push about 25-35% of the intended amount of air through the system. In the cooling mode, your indoor coil should have frozen up. In the heating mode, the unit should have tripped off on high limit.

    Had you recently replaced the blower motor?
    Government is a disease...
    ...masquerading as its own cure…
    Ecclesiastes 10:2 NIV


  5. #5
    Join Date
    Dec 2002
    Location
    Toledo, Ohio, United States
    Posts
    12,911
    Quote Originally Posted by RoBoTeq View Post
    Blowers don't just up and decide to run backwards. What was done to the blower motor that caused it to run backwards?

    With the design of a blower wheel, running backwards will push about 25-35% of the intended amount of air through the system. In the cooling mode, your indoor coil should have frozen up. In the heating mode, the unit should have tripped off on high limit.

    Had you recently replaced the blower motor?

    Twilly could be wrong but thinks maybe he's talking about the condensor.
    No Heat No Cool You need Action Fast

  6. #6
    Join Date
    Aug 2011
    Posts
    19
    No - I'm in a rental property and had been complaining about my a/c not working properly and when I got an excessive electric bill I knew something was definitely wrong with it. I doubt they have done any maintenance to it, and it's an ancient piece of equipment. He said it was the fan that was spinning backward, so I would imagine that would be the condenser fan not the blower... he said he fixed it, but I don't know what he did.

    I really just want to know if a condenser fan that is running the opposite direction could cause my higher electric bills, having warm air coming into the apartment, and the a/c having to run constantly to attempt to satisfy cooling?? And if any other long term damage could be done from it running like that for so long...

  7. #7
    Join Date
    Aug 2011
    Posts
    19
    Quote Originally Posted by Twilly View Post
    Twilly could be wrong but thinks maybe he's talking about the condensor.
    Twilly is correct

  8. #8
    Join Date
    Jun 2005
    Location
    Winston-Salem NC
    Posts
    1,133
    Unit probably had a trip saver type motor installed and the "tech" had it rotating in the wrong direction.
    The one that fixed it most likely switched the leads to the proper rotation.

  9. #9
    Join Date
    Aug 2011
    Posts
    19
    The tech was the same guy... And he and he said upon his first inspection of the unit... July 27th that the fan was running the opposite direction and that he "fixed" it and should be good. As far as I know, no one has touched the unit prior to that... unless their property maintenance tried to do something and actually messed it up, because he's probably not certified to do the work!!

    This still doesn't answer my questions, however... Can a fan that is running in the wrong direction cause:
    -Excessive Electric Bills?
    -Warm air to blow out of ducts?
    -The system to run continuously to try to satisfy cooling conditions?

  10. #10
    Join Date
    Jun 2005
    Location
    Winston-Salem NC
    Posts
    1,133
    Probably.
    OD unit wasn't getting enough air due to fan, makes the entire system not work properly.

    And on the other end, where are you located? Some places have been really hot, by as much as 10-15 degrees above design conditions.
    And your system might be under-sized or over-sized.

    Just a lot of variables involved that makes it impossible to say, "x" was the culprit.

  11. #11
    Join Date
    Dec 2002
    Location
    Houston,Tx.
    Posts
    16,000
    Quote Originally Posted by wright05 View Post
    This still doesn't answer my questions, however... Can a fan that is running in the wrong direction cause:
    -Excessive Electric Bills?.........YES
    -Warm air to blow out of ducts?..........YES
    -The system to run continuously to try to satisfy cooling conditions?.....YES
    __________________________________________________ _______________________
    “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

  12. #12
    Join Date
    Aug 2011
    Posts
    19
    I'm in Michigan, and it has been much hotter than most summers we've seen so far. But at least twice in July my A/C actually stopped working on the days when it was 90+ - I don't know if the fan running backwards and trying to work so hard overheated the compressor or what, but usually when it was REALLY hot it would "crap out" and it would be 87 degrees in my place

    I'm also on a 3rd floor unit, and they keep trying to tell me it's 3rd story heat load that is doing it... but then how is it that 50 story buildings in Florida are able to cool their place... I think that a $220 electric bill for a 1,000 sq foot apartment with one person in it in the evening only (6PM - 7:30AM) is pretty excessive. I think the 3rd floor excuse is the apartment complex trying not to fix something because I'm sure people on the 40th floor of an apartment building aren't paying $3,000 for their electric...

  13. #13
    Join Date
    Nov 2000
    Location
    Eastern PA
    Posts
    68,944
    Quote Originally Posted by Twilly View Post
    Twilly could be wrong but thinks maybe he's talking about the condensor.
    If this is the case, the fan running backwards would at the most overheat the motor and maybe run the head pressures up a bit.
    Government is a disease...
    ...masquerading as its own cure…
    Ecclesiastes 10:2 NIV


Page 1 of 3 123 LastLast

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
Comfortech Show Promo Image

Related Forums

Plumbing Talks | Contractor Magazine
Forums | Electrical Construction & Maintenance (EC&M) Magazine
Comfortech365 Virtual Event