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Thread: Lennox G513 HVAC Units

  1. #1
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    Lennox G513 HVAC Units

    I have a pair of Lennox G513 HVAC units cooling the main and second floors
    of a residence. The compressor/condenser cabinets are mounted on a concrete
    pad positioned away from the main building. The evaporators are integrated
    within the 60's era custom, heavy gauge, commercial quality ductwork for the
    three furnaces in the residence.

    The main floor's compressor is in need of repair/replacement.

    I have been told that these units are obsolete, their refrigerant has been
    banned and parts are NLA - the recommendation is to replace them with
    modern units.

    Are these units in fact no longer serviceable?

    .

  2. #2
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    Thread Starter
    Second request.

    Is my contractor's statement correct, or if I persist am I likely to find
    a company with the skills, knowledge and industry contacts necessary
    to obtain parts for and service my existing equipment?

    .

  3. #3
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    Most older units can be serviced as they have developed some substitute refrigerants for R-22.

    Call around until U find a contractor that will service your unit(s).

  4. #4
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    I'm certain that it CAN be repaired, but SHOULD it be is the better question.

    What is the expected lifespan of this unit? You're looking at a unit from the 60s, so it is approximately 50 years old.

    It has had a good life, put that dog down and put a newer, higher efficiency unit in.



  5. #5
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    Quote Originally Posted by jpsmith1cm View Post
    I'm certain that it CAN be repaired, but SHOULD it be is the better question.

    It has had a good life, put that dog down and put a newer, higher efficiency unit in.
    Let's explore this prospect of changing out the existing units for newer, higher
    efficiency units.

    Is doing so merely a matter of replacing the compressor/condensor cabinets
    on the pads outside the home and connecting them to the existing refrigeration
    lines and evaporator units mounted inside on the furnaces?) Or do newer units
    require different lines and evaporators?

    If new lines are required, is there some means of trenchless replacement that
    will pass the new lines under a paved area that extends some distance out
    from the house foundation? Is there a way to snake the lines through the
    rear foundation wall and forward through the walls/ceiling of a developed
    basement into the mechanical room at the front of the home?

    If new evaporators are required, can they be fitted in place of the existing
    evaporators while retaining the present furnaces and ductwork depicted below?
    What chance is there that after the job is underway and it is too late to
    restore the initial configuration that word will come from the contractor that
    more work than originally anticipated is required?





    .

  6. #6
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    its time for that whole mess to head to the scrap yard, that equipment has far exceeded it's useful life.

    without seeing it there is no way to give replacement options but it is time.

  7. #7
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    Quote Originally Posted by t527ed View Post
    its time for that whole mess to head to the scrap yard, that equipment has far exceeded it's useful life.
    Mess ? Why "mess" ?

    I looked back a bit in your previous posts for recent photo examples of current
    best practices without success. However, judging by what appears in threads
    posted by other owners, current practice comes up short compared to what
    appears in the photos above.

    And what determines useful life? Those furnaces are just some sheet metal
    boxes with motors, blowers, valves, burners and heat exchangers inside.
    It is not uncommon here for ambiant temperatures to drop below -40ºF
    and then remain there for ten to fourteen days each January - the equipment
    shown works on demand and keeps the building and occupants comfortable
    when that happens. It does so at a fuel and electrical cost that is tolerable.

    As I anticipate will be confirmed about the A/C units, changing out the
    furnaces in favour of current equipment will not be a trivial matter. Far
    from just an R&R of suitably sized furnaces, with THIS home, there will
    need to be a wholesale redesign of the fresh and combustion air
    supply/venting with attendent demolition and renovation involving numerous
    trades to accomplish same, along with headaches about how to deal with
    cosmetic issues regarding location of the chimneys and so on.

    In due course, that day will come. However, it seems a bit premature to
    set off on that expensive course of action when all I appear to need is a
    compressor replacement for the m/f unit.

    Quote Originally Posted by jpsmith1cm
    I'm certain that it CAN be repaired, but SHOULD it be is the better question.

    What is the expected lifespan of this unit?
    I am at a stage in life where there is every chance that I will be looking for
    different lodgings within ten years. Recouping the kind of investment required
    by a wholesale refit through personal enjoyment or added resale just doesn't
    seem likely to happen.

    My goal is to restore the functionality of the m/f unit so that for the 30 to 45
    days of each year that we experience 80ºF+ days with high humidity the 2nd
    floor unit is not having to carry the entire cooling burden, I can relax rules
    against oven, d-washer and dryer use during daylight hours and there is back-up
    refrigeration on hand in the event that a problem brings down the 2nd floor unit.

    Thank you for the replies.

    .

  8. #8
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    Your current lines sets can be reused. A new in door coil could be retrofitted on your old furnaces.

  9. #9
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    If your service company wanted to they could find a compressor either a oe or a retrofit r 22 refrigerant is plentiful , although you would better in the long run to replace the complete system .the situation you will find at sale time is buyers will want newer equipment i have replaced units that because the new buyers home inspector recommended it due to age and the sellers never got to use the new units

  10. #10
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    Quote Originally Posted by EddyCurr View Post
    Mess ? Why "mess" ?

    I looked back a bit in your previous posts for recent photo examples of current
    best practices without success. However, judging by what appears in threads
    posted by other owners, current practice comes up short compared to what
    appears in the photos above.

    And what determines useful life? Those furnaces are just some sheet metal
    boxes with motors, blowers, valves, burners and heat exchangers inside.
    It is not uncommon here for ambiant temperatures to drop below -40ºF
    and then remain there for ten to fourteen days each January - the equipment
    shown works on demand and keeps the building and occupants comfortable
    when that happens. It does so at a fuel and electrical cost that is tolerable.

    As I anticipate will be confirmed about the A/C units, changing out the
    furnaces in favour of current equipment will not be a trivial matter. Far
    from just an R&R of suitably sized furnaces, with THIS home, there will
    need to be a wholesale redesign of the fresh and combustion air
    supply/venting with attendent demolition and renovation involving numerous
    trades to accomplish same, along with headaches about how to deal with
    cosmetic issues regarding location of the chimneys and so on.

    In due course, that day will come. However, it seems a bit premature to
    set off on that expensive course of action when all I appear to need is a
    compressor replacement for the m/f unit.

    I am at a stage in life where there is every chance that I will be looking for
    different lodgings within ten years. Recouping the kind of investment required
    by a wholesale refit through personal enjoyment or added resale just doesn't
    seem likely to happen.

    My goal is to restore the functionality of the m/f unit so that for the 30 to 45
    days of each year that we experience 80ºF+ days with high humidity the 2nd
    floor unit is not having to carry the entire cooling burden, I can relax rules
    against oven, d-washer and dryer use during daylight hours and there is back-up
    refrigeration on hand in the event that a problem brings down the 2nd floor unit.

    Thank you for the replies.

    .
    maybe "mess" was a bad choice of word......... the system is 50 years old and parts availabilty for those furnaces is almost non existant from Lennox. in the long run you would be much better off changing out the system rather than putting money into repairs.

  11. #11
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    I can see the cracks in those heat exchangers from way over here.
    "Hey Lama, hey, how about a little something, you know, for the effort." And he says, "there won't be any money, but when you die, on your deathbed, you will receive total consciousness." So I got that goin' for me, which is nice. - Carl Spackler

  12. #12
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    Thread Starter
    Quote Originally Posted by 2old2rock View Post
    I can see the cracks in those heat exchangers from way over here.
    Oh really ?

    You might want to book an appointment with your optometrist. Here, take
    a closer look ...



    I know that these images don't include the critical areas where cracks form
    in exchangers, but I am not inclined to go to the trouble of getting up in there
    just to rebutt your presumption. As one of the forum's Pros, you will recognize
    what you are looking at here.

    catmanacman and beenthere, thank you for your more reasoned support and advice.

    Regarding the evaporator coil and refrigerant lines. I had been led to believe that
    newer equipment runs at higher pressures and that consequently smaller lines are
    required (or perhaps just installed.) In any event, the suggestion locally had been
    that to upgrade the compressor/condensor units, all the A/C components needed to
    be replaced, end-to-end.

    I haven't felt like dealing with any more of the 'oh, just change it out' crowd, so I
    haven't been calling around since my earlier posts and have nothing further to report
    on that score.

    .

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