Residential fridge draw on inverter.

[O C Diver]

My experience to date is marinas lose power for a few days not indefinitely. Even with a small house bank supplemented by solar power should come back on before you get below 50%soc and destroy your bank. Given you take DC and make it to AC to run a AC refrig you add inefficiencies. DC to a DC device avoids that.
You can have the genset flip on automatically. If you leave the boat with full fuel tanks it’s very. Unlikely you will burn through that just running your frig(freezer) and the usual stuff ( bilge pumps, monitoring systems etc.).
Given our lifestyle and to check on other stuff in the past had yacht management stop by. Depending upon setting every week or two. With the current boat have just given food away and shut down the frig/freezer if we’re going to be away for more than a week. You have stuff go bad once and you realize what a mess it makes.
Although the food is great in the windwards the beef throughout the Caribbean is dismal. Hamburger is ok but not steak. Every once in awhile you can find a store that sells to the magayacht crowd and are willing to sell to you. You freeze those steaks and don’t want to lose them.

The point that you're missing is that its not about compressor amperage, its not about the inefficiency of powering through an inverter, it's about total KW consumption.

My 10 cuft. apartment refrigerator with the inverter consumed 60 % +/- of the pwer consumed by my 7 cuft. Norcold AC / DC refrigerator. That is because, in general, RV / boat refrigerators have $hit insulation.

Until RV / boat refrigerator manufacturers have to comply with the standard Energy Guide test you can only guess at whether they're even close to an efficient apartment refrigerator.

Ted

 

[Hippocampus]

See your point Ted. On several boats placed them in oversized cabinetry. Then added suitable closed cell foam while providing ventilation where needed. Part you can’t improve is the doors.

 

[Simi 60]

The point that you're missing is that its not about compressor amperage, its not about the inefficiency of powering through an inverter, it's about total KW consumption.

My 10 cuft. apartment refrigerator with the inverter consumed 60 % +/- of the pwer consumed by my 7 cuft. Norcold AC / DC refrigerator. That is because, in general, RV / boat refrigerators have $hit insulation.

Until RV / boat refrigerator manufacturers have to comply with the standard Energy Guide test you can only guess at whether they're even close to an efficient apartment refrigerator.

Ted

Exactly
It's a part of the reason the 55ft powercat I was building was put on hold.

We needed plenty of fridge freezer for extended cruising

Efficient 12v refrigeration meant thick insulation - in Oz it was an iceer fridge that was $3000 for bar fridge size X 4 or more and bulky.
https://www.iceer.com.au/iceercustomrefrigeration

Or

Household refrigeration which would do it for about $1500 but needed a very heavy battery bank - the absolute enemy of a lightweight catamaran already carrying a tonne of more of fuel (lifepo4 didn't exist then)

Easy now, but we'd already stepped sideways into our current vessel instead

 

[SDTugs]

Has anyone found a production 12v fridge in the 17-19 cubic feet range? It seems like residential might still be the best bet for me just to not give up 5 cubic feet of space.

 

[rslifkin]

Has anyone found a production 12v fridge in the 17-19 cubic feet range? It seems like residential might still be the best bet for me just to not give up 5 cubic feet of space.

At that size range, it's pretty much a choice of residential fridge or a custom built 12v fridge setup.

 

[SDTugs]

At that size range, it's pretty much a choice of residential fridge or a custom built 12v fridge setup.

That is kinda what I had found. I was hopeful that someone had a lesser known manufacturer in their pocket.

 

[luna]

Although the size of the fridge likely matters most, (unless you're into cabinet making,) if you can select a fridge that is designed to be built into your kitchen cabinets you will not have to add some venting or fans to run it efficiently.

This design of fridge typically has a full width vent in the front toe kick where the air is drawn in through the condenser, then into the baffle mounted fan, past the compressor to cool it and then over the drip tray and out the front of the fridge, slightly warmer.
The downside is the yearly chore to clean the dust bunnies off of the condenser which requires you to tip the empty fridge back at about 30º to get the vacuum hose in there.

One such designed fridge is here.

https://www.whirlpool.ca/en_ca/kitc...rigerator-with-freezer-drawer.wrb329lfbm.html

There is likely many more.

 

[Juggerknot]

Thank you for the information. My battery doesn't last long like that. I plan to change it out.

I have done a little looking around and haven't encountered many from the normal manufacturers that make a 17-19 cubic foot unit in native 12v It seems like sticking with a household might be the best bet short of having a custom made with a remote compressor.

It also seems that the big names are doing some seriously low draw energy star stuff like Samsung, LG, GE, ETC.

Thanks again,

B

Correct. The inverter type compressor models are super efficient and not terribly expensive. I have had great luck with Samsung, my previous LG rusted out quickly and became an eyesore albeit, it ran fine still but had to go due to aesthetics.