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  1. #1
    Join Date
    Sep 2006
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    Why not use Multi-split on ducted sytems

    Is it at all common practice to use the any of the various Asian built multi split units as we use heat pumps. That is: installed as an integrated system with full duct work.

    Each of the manufacturers have what they call ducted air handlers, but they are different is shape and size from the typical American setup. It seems like with a little transition duct work the return and supply ducts that many homes have could be reconfigured to work with these air handlers. Adding supplemental and emergency heat would some how need to be figured out. Maybe they have that too and I’ve just missed it.

    If this would work then using a single condensing unit with multiple air handlers would be possible which would be a plus for the many homes that have two systems (or more) – typically one up and one down. These systems have all the bells and whistles one could imagine of a climate control system. The controls are very sophisticated. Plus, it seems like they could be sized for the heat load in order to not rely on strips or other supplemental heat.

  2. #2
    Join Date
    Nov 2000
    Location
    Memphis TN USA
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    6,969
    The blower is not sized for the pressure drop in ducts.
    If the superheat ain't right it ain't charged right.

  3. #3
    Join Date
    Sep 2006
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    Quote Originally Posted by kim View Post
    The blower is not sized for the pressure drop in ducts.
    kim,

    Thanks for the response. I have noticed that many are rated for about .20 ESP, but Sanyo has two units, 36 and 48 BTU that are rated, according to their charts, up above .82 ESP. Other manufactures I've noticed have a way to boost it to about .40 ESP, which may work on some systems as they seem to run with lower CFMs.

    Is that the only issue? How about supplemental heat? Any way to add that?

  4. #4
    Join Date
    Dec 2003
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    709
    You might be able to add a strip heater directly in the duct like you would have in a commercial vav box reheater.

  5. #5
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    Sep 2006
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    1,253
    Quote Originally Posted by hivacer View Post
    You might be able to add a strip heater directly in the duct like you would have in a commercial vav box reheater.
    Yes, I assumed it would have to be along those lines, but it isn't clear whether the controls will be able to call it in when needed.

  6. #6
    Join Date
    Dec 2003
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    709
    Controls can always be added as well, it can be done if you have the money alot of things can be done.

  7. #7
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    Sep 2006
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    Quote Originally Posted by hivacer View Post
    Controls can always be added as well, it can be done if you have the money alot of things can be done.
    Of course, that's where passing the cost benefit analysis gets tricky.

    So what is done for supplemental heat on mini and multi splits are installs?

  8. #8
    Join Date
    Jul 2007
    Location
    Beautiful, Philadelphia, the City of Brotherly Love!
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    1,120

    These Asian ductless unit are not supposed to be a stand alone heating system, none

    that I know of have heating elements. They do however, provide heat in freezing temperatures. They have a defrost cycle, which does not need resistance heating elements to temper the air.

  9. #9
    Join Date
    Sep 2006
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    Quote Originally Posted by AtticAce View Post
    that I know of have heating elements. They do however, provide heat in freezing temperatures. They have a defrost cycle, which does not need resistance heating elements to temper the air.
    Digging around on the Sanyo site I have found a T'stat accessory for use with heat pumps that have strip heat. But, I can't find any strip heat accessory.

    I am looking at the Sanyo ECO-i line that they are marketing as a full solution comfort control (heat pump). They have larger systems, 8 - 12 ton condensers, and smaller ones 3 and 5 ton, that they are marketing for light commercial and residential. In both cases they are designed for multi indoor units. I am looking at the 5 ton for my home. They have lower static air handlers that have a way to adjust the static (about double) and high static units that can work on duct systems up to 1.0 ESP.

    Does anyone have any experience with this particular line?

  10. #10
    Join Date
    Aug 2003
    Location
    Fort Worth, TX
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    11,376
    Quote Originally Posted by mchild View Post
    Is it at all common practice to use the any of the various Asian built multi split units as we use heat pumps. That is: installed as an integrated system with full duct work.

    Each of the manufacturers have what they call ducted air handlers, but they are different is shape and size from the typical American setup. It seems like with a little transition duct work the return and supply ducts that many homes have could be reconfigured to work with these air handlers. Adding supplemental and emergency heat would some how need to be figured out. Maybe they have that too and I’ve just missed it.

    If this would work then using a single condensing unit with multiple air handlers would be possible which would be a plus for the many homes that have two systems (or more) – typically one up and one down. These systems have all the bells and whistles one could imagine of a climate control system. The controls are very sophisticated. Plus, it seems like they could be sized for the heat load in order to not rely on strips or other supplemental heat.
    This is probably what you're looking for:

    http://www.daikinac.com/residential/...oducts&page=55

    Daikin makes a multi-split heat pump system known as VRV, or variable refrigerant volume (who also I believe has a trademark on the VRV acronym as pertaining to VRF systems...variable refrigerant flow). I saw one of these systems at the AHR trade show at Dallas back in January. Pretty impressive, but the condenser cabinet was full of parts and controls. Could be a money maker, could be a PITA. Would likely depend on build quality and installation quality. Daikin likely does well on the build side...but American installations...hmm....better be some good training there so the thing does not become a PITA.

  11. #11
    Join Date
    Sep 2006
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    1,253
    Quote Originally Posted by shophound View Post
    This is probably what you're looking for:

    http://www.daikinac.com/residential/...oducts&page=55

    Daikin makes a multi-split heat pump system known as VRV, or variable refrigerant volume (who also I believe has a trademark on the VRV acronym as pertaining to VRF systems...variable refrigerant flow). I saw one of these systems at the AHR trade show at Dallas back in January. Pretty impressive, but the condenser cabinet was full of parts and controls. Could be a money maker, could be a PITA. Would likely depend on build quality and installation quality. Daikin likely does well on the build side...but American installations...hmm....better be some good training there so the thing does not become a PITA.

    Yes, shophound, that is the Daikin version that I am speaking of. I have focused a bit more on the Sanyo line as Daikin's only goes to 4 ton on the systems that could work (single phase as compared to larger systems that are 3 phase) for a typical resi install. But, like Sanyo they have air handlers designed for static levels as often seen on US duct work.

    I agree, making sure the install is done right would be imperative.

  12. #12
    Samsung also has similar product - Samsung DVM, compressor is tried and true Copeland technology - used by many manufacturers. I am only guessing that some of the big names will incorporate in an effort to raise their SEER beyond 20.

    Samsung's 50,000btu Condenser can power up to 7 units - larger sizes are 3 phase; just like Daikin, Sanyo ECOi and the very complicated City Multi.

  13. #13
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    Sep 2006
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    Quote Originally Posted by FilterFolks View Post
    Samsung also has similar product - Samsung DVM, compressor is tried and true Copeland technology - used by many manufacturers. I am only guessing that some of the big names will incorporate in an effort to raise their SEER beyond 20.

    Samsung's 50,000btu Condenser can power up to 7 units - larger sizes are 3 phase; just like Daikin, Sanyo ECOi and the very complicated City Multi.
    FilterFolks,

    Have you installed any of these?

    Since that original post I have researched the Sanyo Eco-i Mini line more and really like what I see. Of all the manufactures I have researched they, seem to have the highest COP. Plus, the 5 ton unit will deliver about 40K BTU's at 10* (at a COP over 3.0). Won't need much supplemental heat with that much output. To help with that they have output signals off the indoor unit that will make it easy to add supplemental heat.

    The Sanyo 5 ton unit can have up to nine indoor units with total rated capacities up to 130% of the nominal rating of the outdoor unit.

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