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  1. #14
    Join Date
    Jul 2000
    Location
    Guayaquil EC
    Posts
    10,393
    Quote Originally Posted by VTP99 View Post
    icemeister,
    Do you know of a way to figure the capacity on these receivers ?
    Here's a great reference on all things Refrigeration (see p.12):


    Remember that author's name.

  2. #15
    Join Date
    Jan 2010
    Posts
    6,354
    Quote Originally Posted by icemeister View Post
    Here's a great reference on all things Refrigeration (see p.12):


    Remember that author's name.
    Wow great book icemeister. That answered my question and a whole lot more. It went right into the files. Thanks so much for that link.

  3. #16
    Join Date
    Feb 2004
    Location
    Medford Oregon
    Posts
    807
    "Those coils have a total capacity of 1.5 ton"
    not quite correct, each coil handles 5500 btuh @ 10* TD or 550 btuh at 1 TD, at 1 TD, that's 3 x 550 (1650)
    The unit is 10,234 btuh
    so 10,234 / 1650 = 6.20 TD
    ALWAYS RATE COIL AT 1 td, Then divide into unit btuh to view TD
    ex: 12000 btuh coil = 1200 at 1 TD used with 3 different applications
    1. 12000 unit / 1200 = 10 TD
    2. 24000 unit / 1200 = 20 TD (CANDY WAREHOUSE)
    3. 6000 UNIT / 1200 = 5 td (FLOWER BOX)
    as you can see that, 12000 btuh coil is:
    1. 12000 btuh
    2. 24000 btuh
    3. 6000 btuh
    coil does not produce btuh, the unit does, coils handle it
    you cannot say what btuh a coil handles without knowing unit btuh

  4. #17
    Join Date
    Jan 2010
    Posts
    6,354
    Quote Originally Posted by rocket View Post
    "Those coils have a total capacity of 1.5 ton"
    not quite correct, each coil handles 5500 btuh @ 10* TD or 550 btuh at 1 TD, at 1 TD, that's 3 x 550 (1650)
    The unit is 10,234 btuh
    so 10,234 / 1650 = 6.20 TD
    ALWAYS RATE COIL AT 1 td, Then divide into unit btuh to view TD
    ex: 12000 btuh coil = 1200 at 1 TD used with 3 different applications
    1. 12000 unit / 1200 = 10 TD
    2. 24000 unit / 1200 = 20 TD (CANDY WAREHOUSE)
    3. 6000 UNIT / 1200 = 5 td (FLOWER BOX)
    as you can see that, 12000 btuh coil is:
    1. 12000 btuh
    2. 24000 btuh
    3. 6000 btuh
    coil does not produce btuh, the unit does, coils handle it
    you cannot say what btuh a coil handles without knowing unit btuh
    Wow rocket,
    I did not know you could get that many more btu's from a coil by raising the TD.
    Thanks for posting that.
    VTP

  5. #18
    Join Date
    Jul 2000
    Location
    Guayaquil EC
    Posts
    10,393
    Here's a past thread discussing how the evaporator "balances" with the condensing unit capacity:

    http://hvac-talk.com/vbb/showthread.php?t=377632

  6. #19
    Join Date
    Feb 2004
    Location
    Medford Oregon
    Posts
    807
    Here's a little trick to quickly match coils to units
    After sizing your system,
    1.select the condensing unit
    2.Divide desired TD into unit capacity, Answer is coil btuh at 1 TD
    3.In the coil catalog block out the last zero in the 10 TD rating***
    4.Select coil at 1 TD to btuh in item 3

    Example you have a 27000 btuh unit for a beer cooler (desired TD for beer = 15)
    27000 / 15 = 1800
    Now match to coil catalog at 1 TD (i.e. the 1800)
    Most people will look at a 27000 coil, you will choose a 18000 coil
    It's cheaper and better matched (15 X 1800 = 27000) so you can beat out a competitor

    *** crossing out that last number makes this a 1 TD rating

    For a list of desired TD's, download the Heatcraft Engr manual
    http://www.heatcraftrpd.com/products/PDF/Misc/EM.pdf

  7. #20
    Join Date
    Jan 2010
    Posts
    6,354

    Thumbs up

    Quote Originally Posted by icemeister View Post
    Here's a past thread discussing how the evaporator "balances" with the condensing unit capacity:

    http://hvac-talk.com/vbb/showthread.php?t=377632
    That's some good food for ones head icemeister
    Is there a way i can save this thread as a favorite ?

  8. #21
    Join Date
    Jan 2010
    Posts
    6,354
    Quote Originally Posted by rocket View Post
    Here's a little trick to quickly match coils to units
    After sizing your system,
    1.select the condensing unit
    2.Divide desired TD into unit capacity, Answer is coil btuh at 1 TD
    3.In the coil catalog block out the last zero in the 10 TD rating***
    4.Select coil at 1 TD to btuh in item 3

    Example you have a 27000 btuh unit for a beer cooler (desired TD for beer = 15)
    27000 / 15 = 1800
    Now match to coil catalog at 1 TD (i.e. the 1800)
    Most people will look at a 27000 coil, you will choose a 18000 coil
    It's cheaper and better matched (15 X 1800 = 27000) so you can beat out a competitor

    *** crossing out that last number makes this a 1 TD rating

    For a list of desired TD's, download the Heatcraft Engr manual
    http://www.heatcraftrpd.com/products/PDF/Misc/EM.pdf
    rocket,
    I had no idea TD played such a vital role in sizing equipment.
    Thank you for the insight

  9. #22
    Join Date
    Jan 2010
    Posts
    6,354
    O.K. guys here's what i have.
    3'x15'x 8' tall floral display box with 4 front glass doors & 1 side door. Box is being used for beverage with milk included. 3 Russell evaporators model # WE 18-55.
    Up top is a older McQuay air cooled condensing unit ( pontoon style ) with a newer semi-hermetic Copeland compressor model # KALA-016 TAC 800. Running on R 134a.
    One thing i noticed was the TXV's had R22 power elements.
    1/4" liquid line @ TXV's . 1/2" suction lines out. 3/8" & 7/8" line sizes on condenser. Did not see a p-trap at bottom of riser. Also no head pressure control or crankcase heater. Condenser is in a low ambient climate
    Took 13 pds. to clear the sight glass.
    Do you see any problems ?
    Thanks everyone,
    VTP

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