Page 2 of 3 FirstFirst 123 LastLast
Results 16 to 30 of 38

Thread: When should you replace your central air conditioner units?

  1. #16
    Join Date
    Oct 2007
    Location
    Falls Church, VA
    Posts
    2,335
    Blog Entries
    1
    My daughters house has one air handler in the attic. I have no idea how they got that thing up there. There’s a fold down stair and a big return that’s about 30” square. My guess is that they hoisted the AH through that return before putting in the duct.

    That return in the upstairs hallway serves the whole house. We have it on a service contract and I asked the tech about it one day. He said it looked like a hack job. The main plenum should reduce in size as various branches take air. But it’s just this big box. When they replace that thing, it’s not going to be just plugging a new air handler in where the old one was. I think they are going to have to redo the ductwork.

  2. #17
    Funny timing: Our upstairs AC unit just died last week and crew should be replacing it today. It was an appropriately sized Bryant unit. Not sure cause of death but suddenly developed a leak and won't hold refrigerant. Unit was installed, new, in 2012, so almost 10 years old. Only other issue we had previous was the capacitors needing to be replaced. Also, I am not totally unconvinced that the Freezemaggeddon we had here in February didn't have something to do with it. Like, fatigued lines or something. We are having a Lennox unit installed instead of another Bryant.

    Erik
    Ex-SCM and Felder rep

  3. #18
    Join Date
    Apr 2013
    Location
    Kansas City
    Posts
    2,652
    I've replaced AC units twice. Each time they were around 12 years old. The signs they needed replacing were (1) compressor running all the time even on not so hot days. (2) temperature drop (measured at a vent) was less than spec (I think 20º). (3) coils freezing over. (4) electric bill suddenly much higher than normal summer months.
    < insert spurious quote here >

  4. #19
    Quote Originally Posted by Stan Calow View Post
    I've replaced AC units twice. Each time they were around 12 years old. The signs they needed replacing were (1) compressor running all the time even on not so hot days. (2) temperature drop (measured at a vent) was less than spec (I think 20º). (3) coils freezing over. (4) electric bill suddenly much higher than normal summer months.
    Those symptoms could be a sign of low refrigerant. Coils icing over is usually caused by loss of some of the refrigerant.

    Mike
    Go into the world and do well. But more importantly, go into the world and do good.

  5. #20
    Join Date
    May 2007
    Location
    Fort Smith, Arkansas
    Posts
    1,984
    Quote Originally Posted by Mike Henderson View Post
    Those symptoms could be a sign of low refrigerant. Coils icing over is usually caused by loss of some of the refrigerant.

    Mike
    Exactly. Low refrigerant or low air flow are about the only thing that will cause coils to freeze. I just replaced two condensers last month. The old units were beautiful two stage 18 SEER units given to me by my employer. Unfortunately, they were early high efficiency models with complex control boards and early ECM motors. Things are simpler now and hopefully more reliable. Because I was paying for them I bought 16 SEER single stage units. The price difference was significant. In hindsight, the SEER rating is fine but I miss the dual stages which really wrung the humidity out of the house much better that these do. Oh Well.
    Last edited by Michael Weber; 07-07-2021 at 9:53 AM.
    My three favorite things are the Oxford comma, irony and missed opportunities

    The problem with humanity is: we have paleolithic emotions; medieval institutions; and God-like technology. Edward O. Wilson

  6. #21
    Join Date
    Apr 2007
    Location
    New Jersey
    Posts
    1,347
    Blog Entries
    1
    Quote Originally Posted by Erik Loza View Post
    Funny timing: Our upstairs AC unit just died last week and crew should be replacing it today. It was an appropriately sized Bryant unit. Not sure cause of death but suddenly developed a leak and won't hold refrigerant. Unit was installed, new, in 2012, so almost 10 years old. Only other issue we had previous was the capacitors needing to be replaced. Also, I am not totally unconvinced that the Freezemaggeddon we had here in February didn't have something to do with it. Like, fatigued lines or something. We are having a Lennox unit installed instead of another Bryant.

    Erik
    Erik
    Just wondering why you choose Lennox?
    Thanks
    Dennis

  7. #22
    Join Date
    Apr 2013
    Location
    Kansas City
    Posts
    2,652
    Quote Originally Posted by Mike Henderson View Post
    Those symptoms could be a sign of low refrigerant. Coils icing over is usually caused by loss of some of the refrigerant.

    Mike
    Yes, that was true. I omitted saying that the cause of the leaks was unrepairable. Unit would not hold recharge.
    < insert spurious quote here >

  8. #23
    Quote Originally Posted by dennis thompson View Post
    Erik
    Just wondering why you choose Lennox?
    Thanks

    Well, we had a Lennox unit that was still going strong after 15+ years but got rid of it when we put the second story on our house in 2012. Went with two separate units. Both my wife and I felt Lennox was better quality than the Bryants but they were what we could afford when we did the remodel. It was a calculated move, I guess.

    Erik
    Ex-SCM and Felder rep

  9. #24
    Join Date
    Feb 2014
    Location
    Lake Gaston, Henrico, NC
    Posts
    8,973
    I have one tractor that is old enough to use R12 in the AC. It only needed a compressor, when I bought it cheap at an auction, years ago. I'm running R12a in it, which I really believe is pretty much only Butane. Butane makes a decent refrigerant, and is easier on the atmosphere than most of the others, but I guess hauling around a pound of Butane is a lot scarier than hauling a 20 gallon tank of gasoline.

  10. #25
    Join Date
    Oct 2007
    Location
    New Hill, NC
    Posts
    2,568
    I replaced my 1990 vintage Goodman unit three years ago when the compressor died. It's a good thing that I did, as I discovered that the gas furnace flues were starting to crack after almost 30 years of service.

    Previously I had to replace the furnace blower motor (thank you to Graingers for opening up one Fathers Day so that I could source a replacement motor!) as well as some capacitors on the condenser fan. One thing that I have to do every two years or so is to remove the outer housing on the condenser and rinse off the condenser coils, as they will get clogged up with dirt, etc (we live on a farm).

    The replacement unit was a Seer 16 Rudd and my power bill dropped by almost $100.00 per month during the summer. Gas usage remained about the same.

  11. #26
    Join Date
    Oct 2006
    Location
    Minneapolis, MN
    Posts
    5,426
    Quote Originally Posted by Tom M King View Post
    I have one tractor that is old enough to use R12 in the AC. It only needed a compressor, when I bought it cheap at an auction, years ago. I'm running R12a in it, which I really believe is pretty much only Butane. Butane makes a decent refrigerant, and is easier on the atmosphere than most of the others, but I guess hauling around a pound of Butane is a lot scarier than hauling a 20 gallon tank of gasoline.
    One up and coming refrigerant is propane. I think it is more for commercial stuff right now. I couldn't imagine using it in a mobile application like a car.

  12. #27
    Join Date
    Jan 2004
    Location
    Lewiston, Idaho
    Posts
    28,504
    Our home was built in 1966 and had the original HVAC system, a Lennox, in it when we bought the place in 1982. That system lasted 21 years and I replaced it with another Lennox. 2 years ago that system gave out. Due to the Lennox factory fire in Iowa, the two local Lennox dealers switched brands. I chose to go with Bryant.
    Ken

    So much to learn, so little time.....

  13. #28
    Quote Originally Posted by Nathan Johnson View Post
    Mine was installed in 1994.
    I cross my fingers every summer since we bought the house in 2011....so far so good!
    Similar for my old unit in my old farmhouse. Living in Wisconsin has it's advantages for air conditioner longevity. Now, about furnaces.....

  14. #29
    I dunno, I'm thinking butane or propane is just a wee bit too EXPLOSIVE for my taste

    So how/why does ammonia work in RV refrigerators? (something I've never researched)
    ========================================
    ELEVEN - rotary cutter tool machines
    FOUR - CO2 lasers
    THREE- make that FOUR now - fiber lasers
    ONE - vinyl cutter
    CASmate, Corel, Gravostyle


  15. #30
    Join Date
    Oct 2006
    Location
    Minneapolis, MN
    Posts
    5,426
    RV refrigerators heat the ammonia which then somehow absorbs heat in the refrigerator. Big frozen food warehouses also use ammonia for cooling. Ammonia is extremely toxic if inhaled which is why it isn't used for air conditioners and home refrigerators. It is used in RV refrigerators because it works without electricity.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •