A/C Refrigeration

[Dauntlessny]

Originally Posted by ranger42c

Might be useful to compare costs of your own conversion (time, materials, etc.) to the cost of simply buying new DC/AC units that might fit your slots. Shop NovaKool, Vitrifrigo, others...

And then also assess your battery situation to support...

-Chris

Yes. Very good advice.

I spent $2200 to replace my 120v fridge and freezer, with a Vitrifrigo 12/24/120/240 system. It changed my electrical power requirements from 500 amp hours a day to 100. The solar panels can now give me much of that back.

Well worth the money. Don't bother looking at inverter route. that will just add another 75 amp hours per day just to be on.

[Tomaz473]

I have AC fridge compressor and I learned to love it.
It is a power hog (close to 40A), but only need to run for short time to cool the cold plates. It uses dedicated inverter and additional alternator.
Running it from batteries would kill them very fast, so I ran it from solar. (or when the engine was running of course).
I have spent cruising Caribbean for two years and was newer hooked on shore power.
I have rather large solar array (almost 500W peak).
I waited until sun was high enough before I run my fridge. By that time my batteries were fully charged anyway.
I ran it for couple of hours while solar was providing all the energy needed, usually between 10am and 3pm, depending on clouds condition.
Fridge had to compete for sunny hours with water-maker. I never ran both at the same time unless I was using the engine.
On a nice sunny day I could have both fridges cold (two fridges, two cold plates, single compressor) and was able to produce water and I had energy to spare. On less sunny days I did not make water. On very cloudy days my fridge was a little less cold. In two years I only need to run the engine couple of times (99% of all days provided enough energy).
So, if you go solar then AC can be a good fridge. I have a small battery bank (300Ah) as I do not need to store electric energy for the fridge. I cool when I have energy and store cold in cool plates.
In areas with colder water (fridge is water cooled) 1 hour per days is enough or the beer freezes.
The system was designed for charter use (Sunsail) where people normally motor every days for at least one hour anyway, so it keeps the beer cold even if you are not hooked up on shore power during the night. If you are in marina it automatically bypasses inverter and run from AC from shore. That worked great as 500W compressor was able to cool a lot of beverage in short period of time in a marina.