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  1. #14
    Join Date
    Jul 2005
    Posts
    3
    I believe you are ok with an oversised coil. think of it as extra pipe.Now remove that tev or txv and install the factory furnished piston.Suplied with the condenser.untill you can get a 2.5 to 3 ton expantion valve thats all.


  2. #15
    Join Date
    Jun 2005
    Location
    Crisfield, Maryland
    Posts
    20
    I shouldnt have said not efficient. It may very well be.But most coils are matched a little closer than that. Using a larger coil does up the SEER factor. I would be very interested to see how this one works out. I have never seen a coil twice the size condenser.I am always looking for new things.

  3. #16
    Join Date
    Jun 2005
    Location
    Crisfield, Maryland
    Posts
    20
    You might try the orfice that came with the condensor and remove whatever txv is in the line.That might give you a good superheated coil.

  4. #17
    Join Date
    Jun 2005
    Posts
    14
    I really don't want to pull the TXV since it is internal to the cased coil (factory installed). There is an adjustment on it. Should I try to adjust it to get a superheat higher than the 9 I am currently getting? Also if I increase CFM, will I have to readjust the TXV to maintain superheat?

  5. #18
    Join Date
    Jan 2004
    Location
    Lancaster PA
    Posts
    67,903
    I adjust it to aout 13 super heat, and see if the subcool comes up, and the evap delta.
    If it does your on the right track.

    If it doesn't, set it back to factory setting, and get a factory rep out to help you.
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  6. #19
    Join Date
    Jul 2005
    Posts
    3
    now think about it if you could adjust a 5 ton expantion valve down to 2.5 what would be the point in difrent size tev/txvs they are good for a one ton strech max and dont forget to install your liguid line dryer up at the coil for better sqirt of liquid remember your target coil temp is 40 deg.68.5 psi you will never get a 20 deg.dt unless you size up your valve

  7. #20
    Join Date
    Jun 2004
    Posts
    146
    Originally posted by jbplumb
    I recently installed a 2 1/2 ton Goodman CLQ condenser with the manufactures performance rated 5 ton TXV coil on a 2 stage variable speed furnace. The HVAC-Calc shows a heat load of 28,251 BTUH. The system charge is producing a subcool of 15F at 210 psi. Superheat is only about 9F at the condenser. CFM over the coil is 990. The problem is that the unit runs continuously and still can't get the indoor temp below 73F. The air flow is very limited with insufficient cooling to the second floor bedrooms even after adjusting the duct dampers. I have not installed many TXV systems. Do I need to worry about the superheat being so low? Could the system be overcharged? Once the charge is set, can the CFM be increased to provide additional air flow to a second story? What will that do to the subcooling and superheat numbers? Will the TXV compensate for the increased air flow or will it need to be adjusted? Will that have an adverse affect on efficiency? Any other ideas on how to increase comfort and cooling?
    HVAC-Calc shows a heat load of 28,251 BTUH, but wasn't almost all of that sensible load? A CLQ-30 only has sensible cooling capacity of 21,500 BTUH. Isn't a 2 1/2 ton CLQ simply too small?

  8. #21
    Join Date
    Jul 2005
    Posts
    3
    generaly speaking you wil need 1 cfm for 1 square foot of living space and 1 ton of cooling every 400 to 500 square feet depending on were you live the longer an air conditioner runs the greater it is capable of removing humidity i dont have all the calk specs but this helps me in the real world

  9. #22
    Join Date
    Jan 2004
    Location
    Lancaster PA
    Posts
    67,903
    Originally posted by go_redskins
    Originally posted by jbplumb
    I recently installed a 2 1/2 ton Goodman CLQ condenser with the manufactures performance rated 5 ton TXV coil on a 2 stage variable speed furnace. The HVAC-Calc shows a heat load of 28,251 BTUH. The system charge is producing a subcool of 15F at 210 psi. Superheat is only about 9F at the condenser. CFM over the coil is 990. The problem is that the unit runs continuously and still can't get the indoor temp below 73F.
    HVAC-Calc shows a heat load of 28,251 BTUH, but wasn't almost all of that sensible load? A CLQ-30 only has sensible cooling capacity of 21,500 BTUH. Isn't a 2 1/2 ton CLQ simply too small?
    Hmmm.

    He didn't say if that was total, or sensible, that his calc came up with.
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  10. #23
    Join Date
    Jan 2004
    Location
    Lancaster PA
    Posts
    67,903
    Originally posted by acr man
    now think about it if you could adjust a 5 ton expantion valve down to 2.5 what would be the point in difrent size tev/txvs they are good for a one ton strech max and dont forget to install your liguid line dryer up at the coil for better sqirt of liquid remember your target coil temp is 40 deg.68.5 psi you will never get a 20 deg.dt unless you size up your valve

    Good point.

    You uses the same txv on both 4 an 5 ton units, including the stealth 2 stage 50/100.
    So that valve is throtling from 2 to 5 tons.
    He could have the same txv.

    A factory rep will either tell him on the phone that he has the wrong txv, or ask him if he tried to adjust it.

    If he trys to adjust it, its one less delay in getting a factory rep out.


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  11. #24
    Join Date
    Jun 2005
    Posts
    14
    From my understanding, you can throttle back a bigger TXV but there is not enough capacity in a small TXV for a larger condenser. The reason for two or more sizes is cost. Sort of like trucks, you can haul 1 ton of dirt in a 5 ton truck but the opposite it not true. I will be calling Goodman tech support on Tuesday to confirm is adjustment is needed.

  12. #25
    Join Date
    Jun 2005
    Posts
    14
    I posted some pictures of this install on Wall of Pride, topic: Goodman Install. As you can see, the coil is huge. I expect this is the future for higher efficiency units.

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