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  1. #1
    Join Date
    Aug 2002
    Posts
    391
    What is the proper way to read the additional charge for a line set. Do you just correct for the liquid line? Thanks
    The obvious is obvious

  2. #2
    Join Date
    Jul 2002
    Location
    Zelienople, Pa
    Posts
    2,965
    Superheat / subcooling....
    How tall are you Private???!!!!

  3. #3
    Join Date
    Aug 2002
    Posts
    391
    Other than SH, when u install an ac system in the off season.
    The obvious is obvious

  4. #4
    Join Date
    Jul 2002
    Posts
    10
    MOST BRANDS THAT USE R22 SAY .6 OUNCES OF R22 PER FOOT OF LINESET OVER THE RATED LENGTH [WHICH IS EITHER 15 OR 25 FEET DEPENDING ON THE BRAND.] BUT YOU STILL HAVE TO CHECK SUPERHEAT OR SUBCOOLING DEPENDING ON THE METERING DEVICE.

  5. #5
    Join Date
    Mar 2004
    Location
    Grottoes VA
    Posts
    5,856
    Originally posted by r22dave
    MOST BRANDS THAT USE R22 SAY .6 OUNCES OF R22 PER FOOT OF LINESET OVER THE RATED LENGTH [WHICH IS EITHER 15 OR 25 FEET DEPENDING ON THE BRAND.] BUT YOU STILL HAVE TO CHECK SUPERHEAT OR SUBCOOLING DEPENDING ON THE METERING DEVICE.
    This would be for a 3/8 liquid line.
    Karst means cave. So, I search for caves.

  6. #6
    Join Date
    Apr 2004
    Posts
    7,680
    Good question JRC. And for the most part the answer has been posted. For 3/8" you would add .6 oz per foot beyond the nameplate charge for the distance beyond whats rated as mentioned 15 or 25 feet, and any drier installed (a c163 sporlan holds like 13 oz if I remember correctly).

    Most if not all mfg's have restrictions on how long and how much vertical speration can be added. For instance, if you are working a Carrier unit, there is a long line guide you need to consult which suggests a cc heater, liquid line solenoid valve and even wind baffles in some cases. That long line guide is for carrier equipment not trane, york, rheem or anyone elses. They each have guidelines to follow.

    I tell you this much, many units are installed with linesets lengths that are just not supported. Definately consult your installation instructions carefully to make sure you are within the operating limits.

  7. #7
    Join Date
    Aug 2002
    Posts
    391
    thanks for the replies. What I would like to know is the correct way to use the total capacity multipliers. I think I know but just want to check. They range from 1.00 to .92.
    The obvious is obvious

  8. #8
    Join Date
    Apr 2004
    Posts
    7,680
    Multiply your true rated capacity (not generally the nominal capacity) times the capcity factor.

    For instance a 3 ton with a match that actually provides 34,500 btuh's total with a correction factor of .95 The sensible capacity is also affected lets say this unit has a sensible capacity of 25,600.

    34,500*.95=32,775 total capcity
    25,600*.95=24,320 sensible capacity

    The unit has now a total capcity of 32,775 and a sensible capacity with a re-rate to 24,320.

    The information is provided so you can best select the equipment based on the load calculations. In other words if for instance this home required a 28,000 sensible capcity unit, this unit would be undersized.

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