What is a "normal" EWT/LWT delta?

Discussion in 'Maintenance and Troubleshooting' started by bart, Feb 15, 2014.

  1. bart

    bart New Member

    Without getting too specific, I generally see about 3 degrees delta between my EWT and LWT on my closed loop Climatemaster systems. They have been running fine for over twenty years now. In reading through the forums this seams reasonable, but when I look at the performance data from Climatemaster I see numbers around 10 degrees delta. Am I missing something? Also, I assume a two stage system would have a lower delta T when only the first stage is running, correct?

    Bart
     
  2. bart

    bart New Member

    seams = seems
     
  3. Mark Custis

    Mark Custis Not soon. Industry Professional Forum Leader

    Look in your book or online. The operation numbers for a geo system is a moving target. The numbers change as the system works. Your systems are reaching the end of their lives. Keep an eye on them and be ready to change out one or both.

    Mark
     
  4. AMI Contracting

    AMI Contracting A nice Van Morrison song Industry Professional Forum Leader

    "In reading through the forums this seams reasonable, but when I look at the performance data from Climatemaster I see numbers around 10 degrees delta. Am I missing something? Also, I assume a two stage system would have a lower delta T when only the first stage is running, correct?"

    Delta T means little without knowing the GPM. You might be able to reduce the flow some if everything works well. If GPM remains constant then yes you should see a change in DT with different stages.
     
  5. DavidCraig

    DavidCraig Member

    First, you need the manufacture specs for HE (heat of exchange) for your given source water temp and load temp.

    Then you need to know GPM and delta T with accuracy

    One formula used is: Delta T times GPM times 485 equal HE (BTUs moved from the ground). For example: 9 GPM x 5.5 degree F x 485 = 24,007 btu.


    Do you know what the efficiency ratings are for your current unit?
     

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