Click for Llebroc Privacy Matters Click for Westport Click for Abeking Click for JetForums

New inverter AC units

Discussion in 'HVAC' started by MBevins, Jul 28, 2022.

  1. MBevins

    MBevins Senior Member

    Joined:
    May 23, 2008
    Messages:
    993
    Location:
    Windsor On. Canada
    I'm thinking of replacing my split 16K btu with a self contained unit. I have a location and the ducting will work.
    I'm really interested in the new inverter type units.
    Has anyone installed one of these? I assume they're more money, and I'm fine with that, especially if they perform better.
  2. Pascal

    Pascal Senior Member

    Joined:
    Feb 29, 2008
    Messages:
    7,411
    Location:
    Miami, FL
    Inverter unit? As in … powered by DC with an inverter ? Seems to be that only adds a layer of complications to the system. May be nice to run it off the batteries… if you have a BIG bank

    link?
  3. MBevins

    MBevins Senior Member

    Joined:
    May 23, 2008
    Messages:
    993
    Location:
    Windsor On. Canada
    No, the compressor is operated by some internal inverter control, supposedly lowers inrush and has the ability to provide infinite control of the compressor.
    I'll find one and post it.
  4. mapism

    mapism Senior Member

    Joined:
    Aug 9, 2008
    Messages:
    1,845
    Location:
    Sardinia
    Fiammetta42 fitted a unit like that in his boat already some years ago, built by Frigomar, IIRC.
    If he doesn't see this thread, you might drop him a PM.
  5. MBevins

    MBevins Senior Member

    Joined:
    May 23, 2008
    Messages:
    993
    Location:
    Windsor On. Canada
    I was just about to post their website. But for some reason the paste function isn't working here.

    www.Frigomar.com is the site.
    They do have a US office.
    I've read about a couple of others, they escape me at the moment.
  6. Pascal

    Pascal Senior Member

    Joined:
    Feb 29, 2008
    Messages:
    7,411
    Location:
    Miami, FL
    Can’t get it in English even after clicking the English icon. Not sure how an inverter is the solution since an inverter only converts 12/24 VDC to AC. Chillers and large compressors can use freq drives to minimiZe start up.
  7. MBevins

    MBevins Senior Member

    Joined:
    May 23, 2008
    Messages:
    993
    Location:
    Windsor On. Canada
    They've been making them for years in residential, most of those splits you see everywhere are those.

    They draw less current running and in rush.
  8. Pascal

    Pascal Senior Member

    Joined:
    Feb 29, 2008
    Messages:
    7,411
    Location:
    Miami, FL
    But how does an inverter comes in the picture? An inverter takes DC current and “converts” it to higher voltage AC. It has nothing to do with in rush current which on larger units is handled by freq drives.
  9. DOCKMASTER

    DOCKMASTER Senior Member

    Joined:
    Feb 26, 2012
    Messages:
    1,172
    Location:
    Ketchikan, Alaska
    They call these AC units inverter style, just like newer generators are called inverter generators. In essence, they are VFD driven so they have easier start loads and are infinity variable in power that can be applied. It makes them more efficient.
    d_meister likes this.
  10. MBevins

    MBevins Senior Member

    Joined:
    May 23, 2008
    Messages:
    993
    Location:
    Windsor On. Canada
    What he said.:D
  11. Pascal

    Pascal Senior Member

    Joined:
    Feb 29, 2008
    Messages:
    7,411
    Location:
    Miami, FL
    So it’s nothing new, just fancy marketing. Like climate change instead of global warming, education instead of endoctrination, news instead of propaganda…. I get it.
    Capt Ralph likes this.
  12. mapism

    mapism Senior Member

    Joined:
    Aug 9, 2008
    Messages:
    1,845
    Location:
    Sardinia
    No idea of why they came up with the "inverter" wording to distinguish this technology from the old school on/off chillers, but I struggle to see a big attraction attached to the word as such. It's not like they called it "planet saver" or something... :D

    Regardless, the bottom line is that these days most folks would rather associate "inverter" to these air conditioning systems (even more so in domestic installations), without having ever heard of the actual inverters that most of us are used to think of.

    BTW, a nice bonus associated with the linearly variable power that DM already mentioned is that these units are whisper quiet once the preset temp is reached, because instead of constantly turning on and off the fans depending on the thermostat hysteresis, they keep them spinning at all times, but just as slowly as necessary to maintain the temp constant.
    Last edited: Jul 29, 2022
  13. MBevins

    MBevins Senior Member

    Joined:
    May 23, 2008
    Messages:
    993
    Location:
    Windsor On. Canada
    This is apparently a competitor to Frigomar, apparently much cheaper, which is kinda scary since these one's aren't cheap.
    Apparently Dometic also have a line out in the US.

    https://www.clrmarine.com/462m4/manufacturers/v/velair.html

    If I'm going to go through the hassle of replacing my old, I'd like to make sure I'm not buying another dinosaur with a pretty bow.
  14. d_meister

    d_meister Senior Member

    Joined:
    Mar 4, 2010
    Messages:
    447
    Location:
    La Conner, WA.
    +1
    Other aspects are that it reduces the "All or Nothing" on/off characteristics of older systems as the compressor operates on a variable, as needed basis. When set point temp levels are near or achieved, the compressor runs at a lower speed to maintain the temperature as opposed to slamming on or off as the cabin temperature yo-yos up and down.
    Inverters also control frequency, like DC to AC inverters also create the desired frequency from 12 volt 0 Hz to 120 volts 60Hz, for example.
    http://www.frequencyinverters.org/what-is-a-frequency-inverter-106779.html
  15. MBevins

    MBevins Senior Member

    Joined:
    May 23, 2008
    Messages:
    993
    Location:
    Windsor On. Canada
    During some research I came across one I have never seen.

    (Westerbeke Rotary aire ) AC units, all in one, 17K btu.
    Has anyone heard of or had any experience with these ?
    Looks like they've been around a while.
  16. Capt J

    Capt J Senior Member

    Joined:
    Jul 11, 2005
    Messages:
    14,221
    Location:
    Fort Lauderdale
    What I wonder is, does the A/C pump have to run all of the time now to compensate for the unit running all of the time? The electrical draw of the A/C pump would probably kill all savings the inverter units would provide on some/most yachts
  17. MBevins

    MBevins Senior Member

    Joined:
    May 23, 2008
    Messages:
    993
    Location:
    Windsor On. Canada
    When you say AC pump, are you referring to the water or the compressor? The water pump draws next to nothing, maybe 1.5amps at 230vac. And that's probably high.
  18. Pascal

    Pascal Senior Member

    Joined:
    Feb 29, 2008
    Messages:
    7,411
    Location:
    Miami, FL
    I guess if you are desperate to run AC on batteries instead of generator, maybe there will be some
    Energy saving. But, the added complexity of VFD/Inverter loaded with electronics, boards, etc will cost reliability. It s just another layer of possible failure

    Still… an hour of compressor running at half speed compared to half an hour at full speed will probably have the same cooling effect on the same amount of energy

    VFDs are useful on larger units but not on a 16k btu AC.
  19. Fiammetta42

    Fiammetta42 Member

    Joined:
    Sep 28, 2017
    Messages:
    123
    Location:
    Liguria Italy ( boat )
    My boat was built for a Capri hotel owner to taxi guest about .So no AC .
    Great I thought a blank canvas .Previous boat a Sun squeaker has trad Domtech / cruise air kit self contained in each space .We hated them because of the racket .Yes been in visiting marinas in the Med where the shore power on the jetty used to trip or the conventional ac AC just couldn’t cope with meagre incoming supply .

    Sunseeker Fr sold the S/Skr .When I got the Itama back from Naples to Cannes I asked Sunseeker “ know any AC guys “ Answer that came back was an Italian ( with IT plated van ) working the south of France ripping out the factory fit stuff and retro fitting Frigomar .
    Bigger charter 80 s and 90 s etc have the same issues just scaled up .

    Super silent you can sleep .
    No start up spikes so no inadvertently shore power cut outs .
    Very low power requirement.
    Plenty of on line size calculators hovered around 27-29000 BTU for the boat a 14 M sports .
    They fitted a massive 42BTU chiller under a bunk in the rear cabin , it’s silent .Usual chillers in other spaces .
    To give you some idea we only have a 3.5 kv geny and it’s an all electric induction 3 place hob + a 80 Ah charger .
    I can run all three , that’s a 42K btu AC system as well as the other stuff on a geny that weighs 90 kg and is the original 2002 Mase .

    U tubes your friend plenty of vid on the tiny loads and min ramp up .

    As said the brushless D.C. motor has variable speed .No binary on off AC spikes .
  20. Fiammetta42

    Fiammetta42 Member

    Joined:
    Sep 28, 2017
    Messages:
    123
    Location:
    Liguria Italy ( boat )
    From the Frigomar web site .
    It’s all correct in my experience.

    424CCF58-2ECB-4FAD-8733-A952260E8FCB.jpeg