RV Refrigeration: 12v vs 120V Comparison - Helpful Volunteer Research for the Fellow Campers

LaurencetheAdventurer

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So our summer boating is spent sleeping in our toyhauler hooked up to shore power recovering from the day on the lake (from 9am to 10pm we are on the Benny).

The Gas Absorption fridge just can't handle the 100+ degree heat when located on an exterior wall, even with extra fans and insulation - living out of coolers did NOT make my wife happy..... So, I spent a couple of months compiling data on all similar 12v and 120v refrigerators, and inverters, then running samples calculations based on Energy Star Ratings and the few user / blogger measurements I could find. While we are plugged in all summer, we boondock in the winter for about a week at a time - so I needed something efficient - as my little trailer is limited to 2 batteries. I concluded the 120v refrigerators actually required less power, even after the power consumed by the inverter vs similar sized 12v models. Well - apparently this is a hot topic on various forums, most believing the 12v was more efficient. So I set out to prove my hypothesis - I find numbers generally don't lie (though, they certainly can be made to!).

I purchased a 120v GE GPE 11.6 cuft fridge (over 50% more interior than my Dometic 7 cuft 3way) from a scratch and dent store (American Freight - apparently the Sears Outlet - 50% off retail!). I hooked it up to 3 sets of AC meters, and after 3 days of testing - it is currently running 40% above (better) than the Energy Star rating, and 20%+ better than any 12v model per test results from other users. The inverter will consume an additional 15 to 20% of the power I am using, so bottom line - the right 120v refrigerator WILL perform better than it's 12v competitor, at significantly less money (the 12 volt models are $1,400 and up - so even after a $400 Victron Inverter - it's less money), easier to get repaired and/or find parts in stock, and they come in a lot more sizes and I get an extra 2 cuft (that is a LOT more beer) - yet it is a slide in replacement for the existing 3 way Dometic! Just Dreamy, and I expect a much happier wife (I think that will come with all sorts of Benny-fits).

I am going to be compiling more data - but I thought I might find a few campers here looking to upgrade their summer time fridges. Ideally this might be of some help. All sorts of interesting data in the graphs, I am going to continue compiling for about a week.

Enjoy Boating Season!
 

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As a Benny owner and Rv'er. you are correct in your summary. Our diesel pusher had a 3 way refer (Norcold aka Nevercold) that would not keep below 36 degrees. We replaced it with a residental refer and is the best mod we have made to the RV. We went from a 12 cubic ft. to a 18 cubic ft. in the same space as the old refer.
 
Your data for your application may not lie, BUT, in my scenario my small 12v fridge would not move my battery charge condition on a sunny winter day (380 watt solar on roof). I was also watching a12v tv and had the furnace set at 78. If I even turned my inverter on, I would see a slow consistent drop in my battery capacity. It wasn’t much, but I also did not have any load on the inverter. I’m sure if I put a 120v load on the inverter I’m sure it would have increased dramatically.
 
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