Results 1 to 10 of 10
  1. #1

    Line set sizes for R-410

    I have a 2 1/2 ton system to change out and upgrade to R-410. The existing liquid line is only 1/4 inch. Suction is 3/4. The A/H is in an attic on a 3rd floor so replacing the lineset is not an option unless ran externally. If the lineset is flushed properly w/ R-11 what problems, if any , will I have with the 1/4 inch liquid line????

  2. #2
    Join Date
    Dec 2005
    Location
    Cincinnati, Oh
    Posts
    4,923
    what problems with 1/4 line? decreased effeciency. high head pressure. Won't work right. If the AH is on 3'rd floor, an Amana/Goodman Unit requires a reverse trap at AH. I don't care what tonnage the unit is, 1/4 is too small for a 3 story rise.
    "Better tell the sandman to stay away, because we're gonna be workin on this one all night."

    "Dude, you need more than 2 wires to a condenser to run a 2 stage heatpump."

    "Just get it done son."

    Dad adjusted

  3. #3
    Join Date
    Feb 2009
    Location
    Auglaize County, Ohio
    Posts
    56
    It is always best to go by what the manufacuter suggest for your new system.

  4. #4
    Join Date
    Feb 2007
    Posts
    190
    Carrier recently released a bullitin with acceptable line lengths with Puron ststems. I would contact a Carrier dealer. It is not in the product data so some may have missed it.

  5. #5
    Join Date
    Nov 2008
    Location
    Colorado
    Posts
    2,687
    I had heard of the smaller allowable lines with Carrier...... in a thread in here actually. I would think that the high head pressures of 410a would push the limits of 1/4 line on a hot day.

  6. #6
    Join Date
    Feb 2009
    Location
    lancaster ca
    Posts
    68
    all the classes iv tooken on 410A say to change lines out due to oils...iv havent worked with to much 410A but don think it will work due to head preasure

  7. #7
    Join Date
    Nov 2004
    Location
    Naples, Fla.
    Posts
    1,403
    ICP has just released this info on 1/4"

    PIB08-32 5 November 2008
    Alternate Liquid Lines on
    Residential R-410A Split System Air Conditioners
    ICP has evaluated the use of Ό” and c” liquid lines for R-410A refrigerant air conditioner
    cooling-only systems. R-410A refrigerant lends itself well to the use of smaller liquid lines in
    either retrofit applications with existing linesets, or new systems when cost saving is a
    priority. Ό” or c” inch liquid lines may be used for cooling-only applications using a TXV as
    the metering device per limitations on Tables 2 and 3 on page 2 of this bulletin (does not
    apply to 4 and 5 ton models).
    There are several benefits to the use of alternate liquid lines. These include lower install cost
    for replacement jobs when the existing linesets are not accessible for changeout, lower
    lineset cost for new installations, less refrigerant cost for longer linesets, and increased
    reliability due to less total refrigerant in the system. For examples of potential cost savings,
    see page 3 of this bulletin.
    Limitations for alternate liquid lines are based on total equivalent line length and elevation
    difference between indoor and outdoor units. Use the appropriate table on page 2 depending
    on whether the outdoor unit is above or below the indoor unit.
    There are no capacity and efficiency differences between systems using ⅜” liquid lines and
    the listed alternate liquid lines at the equivalent lengths shown, provided a TXV metering
    device is used. The alternate liquid line sizes recommended in this bulletin follow the
    capacity loss charts in the Specification Sheets and, when used with a TXV, achieve the
    same SEER ratings as systems with ⅜” liquid lines. The capacity losses shown in the
    Specification Sheets are related to changes in suction line diameter and equivalent length,
    not liquid line.
    Outdoor units are factory charged for 15 feet of ⅜” liquid line and include charge for the filterdrier.
    Charge must be adjusted according to the lineset being used. See Table 1 for
    appropriate charge adjustments and examples for correct charge adjustment.
    NOTE: Due to the added complexity of heat pump systems, further evaluation is needed
    before releasing guidelines for heat pump systems.
    Table 1. Refrigerant Charge Adjustments
    Liquid Line Size R-410A Charge (ounces per foot)
    3/8”
    0.60
    (Factory charge for 15 ft lineset
    = 15 x 0.60 = 9 oz)
    5/16” 0.40
    1/4” 0.27
    International Comfort Products, LLC
    650 Heil Quaker Avenue, Lewisburg, TN, 37091
    Charging Formula:
    (Lineset oz/ft x total length) – (factory charge for lineset) = charge adjustment
    Example 1: System has 15 ft of line set using existing Ό” liquid line.
    What charge adjustment is required?
    Formula: (.27 oz/ft x 15 ft) – (9 oz) = (-4.95) oz.
    Net result is to remove 4.95 oz of refrigerant from the system
    Example 2: System has 45 ft of existing c” liquid line.
    What charge adjustment is required?
    Formula: (.40 oz/ft. x 45 ft) – (9 oz.) = 9 oz.
    Net result is to add 9 oz of refrigerant to the system
    Vertical Separation (ft) Outdoor unit BELOW indoor unit
    Unit
    Size
    Liquid
    Line
    Diameter
    (w/TXV)
    0-5 6-10 11-20 21-30 31-40 41-50 51-60 61-70 71-80
    18000 1/4 150 150 125 100 75 75 50 -- --
    5/16 250 250 250 250 250 250 250 225 150
    24000 1/4 75 75 75 50 50 -- -- -- --
    5/16 250 250 250 250 250 225 175 125 100
    30000 1/4 30 -- -- -- -- -- -- -- --
    5/16 175 225 200 175 125 100 75 -- --
    36000 5/16 175 150 150 100 100 100 75 -- --
    42000 5/16 125 100 100 75 75 50 -- -- --
    Does not apply to 4 and 5 ton models.
    Table 3. R-410A - Maximum Total Equivalent Length; Outdoor Unit ABOVE Indoor Unit
    Vertical Separation (ft) Outdoor unit ABOVE indoor unit
    Unit
    Size
    Liquid Line
    Diameter
    (w/TXV)
    25 26-50 51-75 76-100 101-
    125
    126-
    150
    151-
    175
    176-
    200
    18000 1/4 175 250 250 250 250 250 250 250
    5/16 250 250 250 250 250 250 250 250
    24000 1/4 100 125 175 200 225 250 250 250
    5/16 250 250 250 250 250 250 250 250
    30000 1/4 30 -- -- -- -- -- -- --
    5/16 250 250 250 250 250 250 250 250
    36000 5/16 225 250 250 250 250 250 250 250
    42000 5/16 175 200 250 250 250 250 250 250
    Does not apply to 4 and 5 ton models.
    Table 2. R-410A - Maximum Total Equivalent Length; Outdoor Unit BELOW Indoor Unit
    International Comfort Products, LLC
    650 Heil Quaker Avenue, Lewisburg, TN, 37091
    Benefits of Ό” and c” Liquid lines
    1. Lower install cost for replacement jobs; no need to change existing lineset
    2. Lower refrigerant cost; less field supplied refrigerant needed for longer
    linesets
    3. Lower cost for new lineset
    4. Less system charge = better reliability
    Example comparing 50ft lineset with ⅝” suction line
    Liquid Line
    Diameter
    Refrigerant
    Required
    Refrigerant
    cost saving*
    Approximate
    lineset cost
    saving**

  8. #8
    Join Date
    Jul 2008
    Location
    Dutchess County, NY
    Posts
    152
    Since you will be installing the AH on the 3rd floor if the vertical seperation exceeds 20ft you will have to follow the manufacturers recommendations for Long Line Sets... some equipment manufacturers dont recommend a vertical seperation of more than 50ft. so choose your equipment carefully, read through the long line set application guidlines as you may also be required to change your Heat mode metering device (piston) if you are installing a heat pump.
    You will also have to read if the equipment you choose recommends flushing agents to clean existing line sets.
    G/L

  9. #9
    Join Date
    Nov 2008
    Location
    Colorado
    Posts
    2,687
    R11 is a good choice to flush- you need all that oil out!!!!

  10. #10
    Join Date
    Feb 2009
    Location
    pinehurst north carolina
    Posts
    54
    follow the manufacturers instructions for efficiency and for warranty. we deal almost solely with r410a and the pressures are sometimes 60% higher if the lineset isn't changed there are several possibilities some of those are that you don't get all the old oils out of the lineset, the 2nd is the pressure issue, and the 3rd is that with the higher pressure of puron there is a greater likelihood that you could develop a leak in the lines if there are integrity problems with the existing lineset. its always best to change the lines when you change the system and there are some attractive measures you can take to offset the lineset on the outside of the structure.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
Comfortech Show Promo Image

Related Forums

Plumbing Talks | Contractor Magazine
Forums | Electrical Construction & Maintenance (EC&M) Magazine
Comfortech365 Virtual Event