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  1. #1
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    Aug 2012
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    Florida Space Coast
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    Condenser Relocation - Lineset Through the Attic or Buried Underground

    House is one story on a slab. The air handler sits on a platform in the laundry room. The lineset and condensate drain go down through a PVC chase under the floor, across the width of the house, exiting on the side where the condenser is. The old 3.5t Rheem condenser is outside a b/r window and "shares" a concrete slab with the irrigation system pump. Physical size of the condenser is such that it's half on, half off the concrete and the "half-off" side where the compressor sits has completely rusted through. Various contractors have quoted replacement equipment and each has their own solution to "correct" the stationing of the outside unit. Here are the three options I've been given.

    1) Most contractors said not to worry, they'd put the condenser in the same place on top of a pad that would be half-on and half-off the existing concrete.... no problem! Most would pull a new lineset and drain through the existing chase, one would pull a new lineset through but re-use the drain, one would simply flush the existing lineset and drain and re-use both.

    2) Two would definitely move the condenser further to the rear of the house, past the 12'x12' atrium which has floor drains to the outside, where it would not be near a window and could sit firmly on a new pad on the ground. Their solution for the lineset and drain would be to flush and re-use the existing drain and run the lineset up through the attic, across and then down through the soffit to the outside, then down the side of the house, covered with a gutter-like chase.

    3) One would move the condenser to the location described above, past the atrium, but would pull the new lineset through the existing chase under the house and then "bury" it and run it underground along the house to the new location.

    I don't like option #1 and have ruled it out. Here in Florida anything sitting outside that's not on a concrete slab sinks into the ground when it rains. I don't think a heavy condenser sitting on a pad that's half-on, half-off concrete would remain level beyond a couple of years.

    Option #2 sounds reasonable. Several neighbors have linesets behind a chase running down the wall from the soffit, apparently due to replacement installs.

    It's option #3 that troubles me. Asthetically, it sounds good, but I'm worried that buried copper lines would corrode and leak after a couple of years.

    Any comments on burying the lineset?

  2. #2
    Join Date
    Mar 2009
    Location
    Mount Holly, NC
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    2,719
    I'd like to see a pic to understand better why they don't have the correct pad for the unit... perhaps pour an additional pad to fully support the unit?
    I've buried linesets before without issues, if you are concerned, you can have them put it in PVC where it's underground.
    The TRUE highest cost system is the system not installed properly...
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  3. #3
    Join Date
    Aug 2012
    Location
    Florida Space Coast
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    503

    Contractors Recommended Against Pouring Concrete

    Quote Originally Posted by vstech View Post
    I'd like to see a pic to understand better why they don't have the correct pad for the unit... perhaps pour an additional pad to fully support the unit?
    I've buried linesets before without issues, if you are concerned, you can have them put it in PVC where it's underground.
    When I suggested pouring additional concrete to enlarge the slab and provide stable support for a new system in the same location, all contractors said that would be way too expensive and they wouldn't recommend it. They said their new "pad" is all that would be needed to provide stability.

    I hope you can see how much the old unit slopes down to the front and to the right where it's off the slab. Slab goes about halfway under the unit. I'd like it moved to the right just past the downspout, closer to the back of the house. The half wall/half screen that separates the atrium from the yard is 12' long between the unit and the downspout.

    The other issue with keeping the condenser at the current location is the requirement to move the disconnect out from behind the unit. Code in Florida doesn't allow reaching over or behind the condenser to pull the disconnect. I don't want anything on or in front of the half wall/half screen that encloses the atrium in case someday it is removed and replaced with full screen. So the disconnect can't be moved to the right. Moving it to the left puts the pump in the way and is also not a good idea, IMHO.
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  4. #4
    Join Date
    Sep 2005
    Location
    Atlanta GA area
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    Both running a lineset in the attic or in the ground has a similar issue: Efficiency loss.

    The small line generally runs around 90-100D temp, while the larger line is more like 50-60D... note these are loose numbers as an example.

    It does not take much thinking to understand if there is a source of heat or cold that sucks away those temps... it drops efficiency.

    If it were me, I would run it across the attic. While the attic is potentially warmer... contact with air is a lot less reactive in removing heat or cold from the tubing than reaction with contacting soil in the ground.

    The suggestion of burying the tubes in PVC would work, so long as both ends are sealed water-tight. If the PVC gets full of water... serious thermal transfer will happen and efficiency will drop.

    BTW: Up here where I live... we end up moving units regularly. It is not as big a deal as it seems like... just have to deal with the issues you mentioned. Glad we do not have that 'reach over' code... yet...
    GA-HVAC-Tech

    Galatians 2:20-21; Colossians 1: 21-22 & 26-27; 3:1-4; Romans Ch's 5-6-7-8

    2 Chronicles 7:14

    Quality work at a fair price with excellent customer service.

  5. #5
    Join Date
    Jul 2010
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    nebraska
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    1,620
    Through the attic to a new location would be my choice, with both liquid and suction lines insulated separately. New unit would be at least a foot off the wall too.

  6. #6
    Join Date
    Aug 2007
    Location
    Northern VA 38 degrees N by 76 degrees W
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    5,046
    Quote Originally Posted by ga-hvac-tech View Post
    Both running a lineset in the attic or in the ground has a similar issue: Efficiency loss.

    The small line generally runs around 90-100D temp, while the larger line is more like 50-60D... note these are loose numbers as an example.

    It does not take much thinking to understand if there is a source of heat or cold that sucks away those temps... it drops efficiency.

    If it were me, I would run it across the attic. While the attic is potentially warmer... contact with air is a lot less reactive in removing heat or cold from the tubing than reaction with contacting soil in the ground.

    The suggestion of burying the tubes in PVC would work, so long as both ends are sealed water-tight. If the PVC gets full of water... serious thermal transfer will happen and efficiency will drop.

    BTW: Up here where I live... we end up moving units regularly. It is not as big a deal as it seems like... just have to deal with the issues you mentioned. Glad we do not have that 'reach over' code... yet...
    I believe you are on 2005 NEC, take a look at 110.34 A Spaces About Electrical Equipment.

  7. #7
    Join Date
    Aug 2012
    Location
    Florida Space Coast
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    503
    Quote Originally Posted by ga-hvac-tech View Post
    The suggestion of burying the tubes in PVC would work, so long as both ends are sealed water-tight. If the PVC gets full of water... serious thermal transfer will happen and efficiency will drop.
    I can see how the existing PVC chase running under the concrete floor wouldn't collect water, since it slopes down to the outside where it connects with the condenser. Any water backing up into the chase during heavy rains would be drained by gravity once the rains stopped. But running another PVC chase underground from where the lines come out from the house another 12-14 feet to where the new unit will be, I don't see how that could be made "water-tight", and there is no way that it would be drained by gravity flow. Am I missing something?

    I just finished reading an article in a 2011 Property Owners Association newsletter from The Villages, a newer community in Central Florida. Many homeowners were having compressor failures due to buried linesets and were having to re-route the linesets through the attic to cure the problem.

    I also researched and found prior posts in this forum from 2005 - 2009 talking about
    Carrier "prohibiting" buried linesets on residential units.
    Last edited by Florida Joy; 09-06-2012 at 07:08 PM. Reason: typos & additional info

  8. #8
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    Sep 2005
    Location
    Atlanta GA area
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    Quote Originally Posted by second opinion View Post
    I believe you are on 2005 NEC, take a look at 110.34 A Spaces About Electrical Equipment.
    Was no aware of this... recently was at a new housing site... this code was not being followed. Guess not every contractor or inspector follows the codes.
    GA-HVAC-Tech

    Galatians 2:20-21; Colossians 1: 21-22 & 26-27; 3:1-4; Romans Ch's 5-6-7-8

    2 Chronicles 7:14

    Quality work at a fair price with excellent customer service.

  9. #9
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    Sep 2005
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    Atlanta GA area
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    Quote Originally Posted by martyinlincoln View Post
    Through the attic to a new location would be my choice, with both liquid and suction lines insulated separately. New unit would be at least a foot off the wall too.
    Good point about insulating the small line (LL) also.

    Quote Originally Posted by Florida Joy View Post
    I can see how the existing PVC chase running under the concrete floor wouldn't collect water, since it slopes down to the outside where it connects with the condenser. Any water backing up into the chase during heavy rains would be drained by gravity once the rains stopped. But running another PVC chase underground from where the lines come out from the house another 12-14 feet to where the new unit will be, I don't see how that could be made "water-tight", and there is no way that it would be drained by gravity flow. Am I missing something?

    I just finished reading an article in a 2011 Property Owners Association newsletter from The Villages, a newer community in Central Florida. Many homeowners were having compressor failures due to buried linesets and were having to re-route the linesets through the attic to cure the problem.

    I also researched and found prior posts in this forum from 2005 - 2009 talking about
    Carrier "prohibiting" buried linesets on residential units.
    I believe I remember this from years ago... Long technical story. Good this info was available.
    GA-HVAC-Tech

    Galatians 2:20-21; Colossians 1: 21-22 & 26-27; 3:1-4; Romans Ch's 5-6-7-8

    2 Chronicles 7:14

    Quality work at a fair price with excellent customer service.

  10. #10
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    Aug 2007
    Location
    Northern VA 38 degrees N by 76 degrees W
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    Quote Originally Posted by ga-hvac-tech View Post
    Was no aware of this... recently was at a new housing site... this code was not being followed. Guess not every contractor or inspector follows the codes.
    And this leads the technician to stand on his head trying to repair a piece of equipment and tacking 3 to 4 times as long to make the diagnosis or repair. Aside from the danger of electrocution when trying to take readings.

  11. #11
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    Aug 2012
    Location
    Florida Space Coast
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    Quote Originally Posted by Florida Joy View Post
    I can see how the existing PVC chase running under the concrete floor wouldn't collect water, since it slopes down to the outside where it connects with the condenser. Any water backing up into the chase during heavy rains would be drained by gravity once the rains stopped. But running another PVC chase underground from where the lines come out from the house another 12-14 feet to where the new unit will be, I don't see how that could be made "water-tight", and there is no way that it would be drained by gravity flow. Am I missing something?

    I just finished reading an article in a 2011 Property Owners Association newsletter from The Villages, a newer community in Central Florida. Many homeowners were having compressor failures due to buried linesets and were having to re-route the linesets through the attic to cure the problem.

    I also researched and found prior posts in this forum from 2005 - 2009 talking about Carrier "prohibiting" buried linesets on residential units.
    Quote Originally Posted by ga-hvac-tech View Post
    I believe I remember this from years ago... Long technical story. Good this info was available.
    Still considering options for moving the condenser about 12-14 feet and how to extend the lineset. What would be the downside of running the new lineset through the existing chase under the foundation, and then running it through a horizontal chase mounted to the wall a foot or so off the ground to the other side of the atrium? Both lines insulated, with ventilation/drain holes along the bottom of the horizontal chase to keep it from collecting water, and painting the chase to match the wall. I'm thinking that would work and provide less loss of efficiency than running a much longer lineset up and across a hot attic and then down the wall through a vertical chase.

    What say the experts?

  12. #12
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    Sep 2005
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    Atlanta GA area
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    Quote Originally Posted by Florida Joy View Post
    Still considering options for moving the condenser about 12-14 feet and how to extend the lineset. What would be the downside of running the new lineset through the existing chase under the foundation, and then running it through a horizontal chase mounted to the wall a foot or so off the ground to the other side of the atrium? Both lines insulated, with ventilation/drain holes along the bottom of the horizontal chase to keep it from collecting water, and painting the chase to match the wall. I'm thinking that would work and provide less loss of efficiency than running a much longer lineset up and across a hot attic and then down the wall through a vertical chase.

    What say the experts?
    Something to think about; the 'experts' who do the install will know this: Better to NOT run a lineset so it forms a large 'pocket' in its run. What happens is the oil floating around the lines will gather, and potentially STARVE the compressor. Be sure your idea has taken into consideration smooth lineset runs.
    GA-HVAC-Tech

    Galatians 2:20-21; Colossians 1: 21-22 & 26-27; 3:1-4; Romans Ch's 5-6-7-8

    2 Chronicles 7:14

    Quality work at a fair price with excellent customer service.

  13. #13
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    Florida Space Coast
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    Quote Originally Posted by ga-hvac-tech View Post
    Something to think about; the 'experts' who do the install will know this: Better to NOT run a lineset so it forms a large 'pocket' in its run. What happens is the oil floating around the lines will gather, and potentially STARVE the compressor. Be sure your idea has taken into consideration smooth lineset runs.
    It's been my understanding that the accumulator (comes standard with heat pumps) protects the compressor from such "starvation". True or not?

    Also, what constitutes a "large pocket" in the lineset? As you can see in the pix I posted, the current lineset makes a pretty sharp U turn from where it exits the foundation to reach the condenser.

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