Split or Attic package

Discussion in 'Geothermal Heat Pump Applications' started by SURRYEQUIP, Feb 27, 2013.


    SURRYEQUIP New Member

    I am weighing pros and cons of a 2.5 ton split system versus a package unit. This is in a rural area so quiet is an issue. The air handler or unit (whichever) will be in the attic above the master bedroom. There will be approx 25 ft. vertical separation and 10 ft. horizontal. The additional equipment needed for the split unit that vertically separated vs quiet and water risk with an attic installation. Pros and cons? What is likely to be the quietest unit available? Thanks Charles
  2. mtrentw

    mtrentw Active Member Industry Professional Forum Leader

    I just installed this past summer. My $0.02.

    I installed 2 units in house and apartment addition. House has a package in basement, apartment is package unit in attic.

    I was replacing an oil furnace which already had 3/4" copper piping running from the basement furnace to the attic for hydronic air handler coil. Because of this, i elected to re-use the existing pipe to carry the loop field water.

    My loop water is protected down to 15 degrees. In attic, I had to be careful about DSH water piping and freeze concerns. Not sure where you are located, your winter attic temps and DSH need.

    If I did not have the pre-existing pipe from basement to attic, i would have used a split system in the basement.

    As far as noise, I notice both units in the respective house/apartment. I mounted the attic unit to the top chord of the roof truss with all-thread and vibration isolation mounts. I still notcie some high pitch vibration to transmit through the framing and ductwork.

    In the main house unit in basement, it seems to be more of a lower pitch cyclical hum. After a few months, I no longer notice either unit unless I am looking for it.
  3. engineer

    engineer Well-Known Member Industry Professional Forum Leader

    I (and Florida energy code) am not fond of system installs in vented attics outside the home's pressure and thermal envelopes.
  4. Kogashuko

    Kogashuko Member

    I actually brought this up to my wife as a reason to replace both our air source units with one ground source located in the garage. No matter what I would need another unit since my current, fairly new, air source units will not handle our addition. For about $200 more we can get a 4 ton instead of 3 ton. The way I crunched the numbers a water source will not suffer the loss of BTU in the cold winter or hot summer that the air sources do. I can keep the actual load of my house still at 4 tons but get the air handler out of the attic and into an insulated garage. The duct work would still be in the attic but I have no issues building a plywood box and blowing R38+ in around it.
  5. Mark Custis

    Mark Custis Not soon. Industry Professional Forum Leader


    Did you look at the Unico systems web site. Your duct work worries are over. I need a trip towards the Beltway.


  6. Kogashuko

    Kogashuko Member

    Looks very nice and a water source unit would fit nice in the corner of the garage. But I dont think the system will fall in my price point. $4000 for the water to water unit plus $1500 each for three air handlers is too much right now. I can swing a heat pump unit and buy the pipe here and there over the course of the project.

    I am very interested in your some threads I read where you use pex for loops? That stuff ends up being cheaper that HDPE for me if I cant buy it locally. Most of it comes in 3/4 in rolls. Would be even nicer if I could use 300 rolls but that would put pex joints underground of short 300 feet loops which I think would be a problem. My flow software did say 7 300feet loops would work but it is only software.

    -edit I dont know if forum rules prevent pricing discussion, sorry this is just a general budget pricing discussion.
  7. engineer

    engineer Well-Known Member Industry Professional Forum Leader

    This ain't HVAC-TALK with its anti-$ moderating Gestapo.

    That said, most of us shy away from precision pricing analysis owing to widely differing costs, codes, bureaucracy, wage rates, etc in different areas.
  8. Mark Custis

    Mark Custis Not soon. Industry Professional Forum Leader


    Are you not listening?

    If you use a manifold you can put big pipe from the house to the well and use a small pump, and drop coils in the well and not mess up your drinking water.

  9. Kogashuko

    Kogashuko Member

    I am not sure it will dissipate enough heat but I am going to try. Worst case scenario would be I have to install a loop field which I am thinking I will have to do.

    Although, with 600 gallons of water in the well there is a lot more water than would be in the loop water also is a much better conductor than plastic so I would need a much smaller loop. I also wouldnt want to use antifreeze in the system and risk a leak killing everyone in my house. Could be a problem if loop temp goes down.

    Couldnt see efficiency being any worse.
  10. Kogashuko

    Kogashuko Member

    What are you thinking about 300 foot loops of 1" or larger pex since I dont have socket fusion? Or better yet I found this Hyperloop stuff that could be dropped in at 6' tall and 3' wide coil.

    I could also see constructing something like this http://youtu.be/ybWGZ8li-GE
    Last edited: Mar 26, 2013
  11. Mark Custis

    Mark Custis Not soon. Industry Professional Forum Leader

    What I am proposing is building a radiant floor in the well.

  12. Kogashuko

    Kogashuko Member

    Essentually moving heat in and out of the well water in and out of the house.

    I am just hoping the water from the well doesnt get heated or chilled faster than the surrounding ground can absorb it. Little research shows the cement does not have horrible thermal conductivity. Would be a lot more surface area than a loop field.

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