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Old 29-10-2019, 10:04   #1
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Newer technology A/C systems

I have a couple reverse cycle A/C units that need replacing. I am interested in the newer technology units that run with variable speed inverter compressors. I am curious as to why there seems to be little info on suppliers here in the U.S. Why hasnít this technology become more mainstream yet? I was looking online at the advertisement of the Dometic Turbo units and this has been out since 2007. Surely in 12 years someone has improved their design. I donít want to drop several thousand on replacing units with 12 year technology only to have them become the old style a year later.
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Old 29-10-2019, 11:17   #2
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Re: Newer technology A/C systems

There are several things holding back the use of variable speed compressors and the attendant electronics that go with them.
1 Voltage or rather the lack of stability. On shore you can reasonably expect fairly stable input on a vessel you can get quite a difference in voltages, the power supplies don't quite like it.
2 Again very dependant on electronic circuit boards that are expensive to replace and maybe difficult to get. Now this maybe all right for some but if you are a commercial operator and a dinner party or charter depends on the unit running that day it maybe an issue.
That being said there are several manufacturers that are building units, TMD comes to mind.
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Old 29-10-2019, 11:39   #3
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Re: Newer technology A/C systems

It amounts to the fact that they arenít needed. The only advantage a variable speed compressor would give is that it could run continuously varying speed to control the amount of cooling necessary as opposed to the current on and off system.

Very similar thing in Inverter generators, why arenít larger generators inverter generators and take advantage of the variable speed? Well Iíve asked that question only to be told there isnít any advantage once you get beyond small generators, that Diesels in particular donít use much less fuel at lower RPM.
I can infer that a variable speed compressor for air conditioning wouldnít add much that one that shuts off and on does.

One thing I really liked about our Toyota Prius is the airconditioner, being electric itís output wasnít tied to engine RPM, and Iím almost certain itís a variable speed compressor by using a brushless DC motor.

Now what confuses most people is that a brushless DC motor like our refrigerators are actually AC motors. A brushless DC motor is lighter, lasts longer and is more efficient than a brushed DC motor or an AC motor.

But Iím not sure how one would be run from AC power, it is first converted back to DC, to just then be converted to variable frequency AC again? Or would it take AC at a set frequency and then convert the frequency to drive motor speed?
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Old 29-10-2019, 11:46   #4
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Re: Newer technology A/C systems

Thanks for the responses. I have 5 units on my boat and was hoping that these newer A/c's would allow me to run all five with less amp draw as I can only now run 3 at the same time while on gen power and 4 while on shore power. But I think my main issue is start up amps so maybe I would be just as well off with the Dometic Turbos and install easy start soft starts on them?
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Old 29-10-2019, 11:51   #5
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Re: Newer technology A/C systems

I donít know, I could see how they could almost eliminate that start up surge common in most normal compressors.
But just as a fool I guess, but why donít good manufacturers have soft starts in their AC systems from the factory?
Maybe some do? If I were a manufacturer I think I would.
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Old 29-10-2019, 12:12   #6
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Re: Newer technology A/C systems

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I donít know, I could see how they could almost eliminate that start up surge common in most normal compressors.
But just as a fool I guess, but why donít good manufacturers have soft starts in their AC systems from the factory?
Maybe some do? If I were a manufacturer I think I would.
I agree, certainly in marine systems where power is limited a considerable amount of the time. The after market soft start is only about $175 so it couldn't be half that for them to design it in the A/c originally.
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Old 29-10-2019, 13:03   #7
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Re: Newer technology A/C systems

From my notes, sorry not sourced:

Frigomar's 230V variable speed brushless inverter tech is apparently amazing, their 16000btu unit uses under 1400W.

And crazy slow controlled ramp up, no surge demand at all.
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Old 29-10-2019, 13:57   #8
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Re: Newer technology A/C systems

I just turned on my 16,000 BTU Webasto which is an economy Unit.
It pulled 11 amps at 120VAC including the water pump which isnít reported in AC consumption figures.
Thatís 1320 W, which is of course less than 1400, but not so much to be a real big deal
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Old 29-10-2019, 14:31   #9
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Re: Newer technology A/C systems

Very nice, that plus a slowstart, can probably save a lot of coin over importing the Frigomar

link to that model?
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Old 29-10-2019, 14:31   #10
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Re: Newer technology A/C systems

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From my notes, sorry not sourced:

Frigomar's 230V variable speed brushless inverter tech is apparently amazing, their 16000btu unit uses under 1400W.

And crazy slow controlled ramp up, no surge demand at all.
Do you happen to know the cost of the unit? Although I need 120v not 230v.
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Old 29-10-2019, 14:39   #11
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Newer technology A/C systems

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Very nice, that plus a slowstart, can probably save a lot of coin over importing the Frigomar

link to that model?


This is to all of them, a quick Google shows they go for $1200 to $1300, the 16k that is
https://www.webasto.com/fileadmin/we...asheet-fcf.pdf
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Old 29-10-2019, 16:46   #12
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Re: Newer technology A/C systems

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Do you happen to know the cost of the unit? Although I need 120v not 230v.
Italian I think, not available in 'murican.

If you have to ask you can't afford it, was just tossing out a highly reco'd example
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Old 29-10-2019, 16:58   #13
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Re: Newer technology A/C systems

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Italian I think, not available in 'murican.

If you have to ask you can't afford it, was just tossing out a highly reco'd example
I appreciate the reply, but you must have misread my question because Iím not really interested in what you think I can afford or not. I simply requested if anyone here is familiar with these units where I could buy them and Iím sorry if I gave the impression that I was poor but how much they cost.
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Old 29-10-2019, 17:07   #14
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Newer technology A/C systems

If your in the US, here is apparently the dealer.
Iíd give them a call in the morning. I donít see a price but I didnít look hard either.
http://www.titanmarineair.com/services/frigomar
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Old 29-10-2019, 17:08   #15
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Re: Newer technology A/C systems

Did not mean that. IMO not worth investigating, especially if you don't want to convert to Euro style 240V.

Edit: ooh that's new, maybe they do make 110V versions now.

Anyone getting the skinny please report back here
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