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SubCooling per floor of a house.

Getting a little progress done. One chart shows SC per 10' of riser.

           10'=4.9psig drop=1.6*f temp drop(SC)

            20'=9.7psig drop=3.1*f temp drop(SC)

           30'=14.7psig drop=4.7*f temp drop(SC)

           LL/FD = 4' of copper         SGMI=3'      LLSV=5' 

          1/2" 90* ell , long radius = 1' of copper

another chart is slightly different , 10' of rise is 2* of SC and 5* of SC at a 30' rise


  • icesailor
    icesailor Member Posts: 7,265
    Lots of Loss:

    Seeing as how you brought that up,

    If I want to know the amount of heat energy put into my heating system, I measure it as it leaves the boiler and when it returns back to the boiler. If I really want to be accurate, I should measure it when it enters the first heat emitter and leaves the last. That will show me if I am loosing any heat energy before and after the emitters.

    So, you guys (mostly I guess) measure the pressures at the compressor/condenser. Because of your FM gauges, you can read the pressures and it gives you the temperatures. Or so it seems. So in trying to solve my problems which we have discussed, I discovered this. Understand that I don't have a set of FM gauges. So everything is done with a thermometer with my Multi-meter.

    When the liquid line leaves the compressor, it is 88*-89*. When it gets to AH, it is 80*-81*. When it leaves the AH, the suction/vapor line is 41* to 43*. When it gets back to the compressor/condenser, it is 42* to 43*.  The lines are 40' +/- with about 30' direct burial under the slab. Because the temperatures drop going TO the AH and RISE coming back to the Compressor, it seems to me that the difference is heat transfer in the ground. When I first turn the system on, the differentials are higher. After running for over an hour, the measurements steady off to what I printed out. IE: the liquid leaving the compressor will be the same but it will be cooler at the AH when it goes in to the AH

    The surrounding ground gets transferred heat from the lines.

    Did I tell you about the time a couple of years ago that I had no water in a store unit because all the water service lines and AC lines were buried together to 6 stores? And one had a compressor that was low on liquid and super cooling the ground which froze the water service to one unit? The bad store wasn't getting cool, it ran for 5 months, and no one noticed until I came along. Like they thought it was normal to set a cooling thermostat to 65* but it never got below 80 degrees. Normal. Numb Nuts.

    As far as my problem in my Condo, I had 12" + of insulation blown in the other day. A minimum of R-30 everywhere. They even covered most of the flex duct.  The AC goes down to 75* without a problem and the condensation around the metal ceiling grills stopped. Before they blew the additional insulation in, there were many spots on the ceiling that had less than 2" of insulation and places where it was bare sheet rock. The ceiling temperatures dropped in relation to how they were before and the OAT and humidity.

    I know it is working better because my wife is happy. She notices that it runs far less than it did before.