Residential RV refrigerators

Hi Phil,

Yes, I have confidence in the kit.

#1 it would prevent fire

#2 it prevents overheating which causes the anti rust material to crystallize.

#3 it is not a lot of money

#4 Chris Bryant (who is one of the good guys) recommends it.

I'm on a limited budget and absorption fridges are outrageously expensive to have replaced in Canada ($3000.00). I'm also full timing so I can't really live too comfortably without a fridge. My job might make it quite hard to travel down to the USA for a replacement. If they ask at the border if I've done any repairs......well I'll be honest. I won't volunteer information however.

After next year's upgrade on the solar system I'll be sitting in the cat bird's seat as far as replacement of the fridge with a residential unit. Until them, I have to hope the Dometic unit will continue to function. Also after the upgraded solar, most of the time I should be able to run the existing absorption Fridge more or less directly from the panels.

Both Dometic and Norcold have poor track records. The older fridges appear to be much more robust. I.E. the unit in my previous RV is a Norcold from 1987, It has more space, and still cools well on electric.

Don,

Do you have complete confidence in the design principle(s) behind these kits .... or is there a bit of smoke-and-mirrors going on?

I wonder why Dometic, Norcold, etc., don't automatically build more protection into their units if it's fairly straightforward to do so?

Hi,

I've ordered the kit to prevent damage from being out of level and will install it this spring. Until then I'll continue to try to be ultra level.

MrWizard wrote:
I never level the RV to buy groceries or shop kmart or what ever...

The same with us.

You don't have to be anywhere near that paranoid for short periods of off-level parking with an RV absorption refrig. We once parked way off level at a picnic for several hours in the heat of the day and only after several hours did I notice the thermometer inside the refrig was rising above 38 degrees ... and that was probably mostly caused by us not having much in the freezer to act as a cold thermal mass so as to help maintain overall internal temperatures. We would never camp as far off-level as we were that day. I called the Norcold company the next day regarding the incident and they said a few hours of operation at extreme off-level here and there would not affect the refrigerator's long-term reliability.

One of these days maybe the RV manufacturers will finally get it right and mount RV refrigerators on gimbals so they are always level no matter how the RV is parked ... or better still, the refrigerator manufacturers should come up with a way to mount only their sensitive internal plumbing on an internal gimbal arrangement within the refrigerator.

Hi Mr Wizard,

3kwh sounds amazing. The only reason I could run my absorption fridge on 120 volts was because of the shortness of the trips. As a full timer I no longer have that luxury.

@PT ..my 3 previous class A RVs had LP fridge, i never ran them on electric
I never level the RV to buy groceries or shop kmart or what ever
IF the parking lots had been that far OFF level I doubt they would have much business

this RV came with fridge DOA, repairs did not work, i switched to residential
because I Knew i was going solar and i knew I had room for the batteries and of course had been already been full time for many years

yes we love our fridge, but that does NOt make it the Optimum choice for the avg RV'r

even with solar we run the generator almost every day, always for heavy loads,

the last 2 days we collected 3050.5 watt-hrs total from solar power,

i would never run an absorption fridge on electric EXCEPT in an emg, of NO LP

the electric power use is too heavy, 345w heating element
but that tank of LP burns a long time on that little flame that keeps the fridge cold, 10gal, can easily provide fridge "ONLY" for 30days, thats cheap compared to generator fuel to charge batteries

I would think that even with the hoggiest power hog :) a residential fridge would still draw a half, if not most, of their daily energy draw.

I agree that for a hardcore dry camper - that doesn't have a generator - the way to go is LP fridge. For sunnier locations, it can also be a 12V fridge, with a solar upwards of 300W (solar size would depend on both fridge size and other loads), and a battery bank at least 300 AH to get through occasional dark days.

Well, if you are a hardcore dry camper then the RV fridge is the way to go. However if you only occasionally dry camp and are okay with installing a reasonably robust 400- 600 watt solar system then a residential is a great way to go. I would also recommend having a minimum of 4 X 6 volt batteries which of course many coaches come with. If you can add a couple more even better. Both types of fridges have their advantages. We have a 22 cubic foot residential that draws about 95 to 110 watts off the inverter when it is cycled on but it it only cycles on for about 20 to 30 minutes per hour. I can tell you we would never go back to an RV type fridge but we only dry camp about 40 to 50 days per year. We also run the genny about 45 to 90 minutes per day but really that's because we are power hogs and run things like under counter beverage heater, Kuerig coffee makers, toaster, microwave, hair dryer etc etc etc. If it was just the fridge I doubt we would need a generator...as long as we get a little sun. :)

Good luck on the project.

As usual in Tech fprum, the topic went off track and downhill very quickly :)...

danrn wrote:
am concerned about the power usage of the residential frigs. I know they use inverters to power them, but how long can the inverters and batteries maintain the power? What I would like to know is if I don't have a generator, and I am dry camping, should I be concerned about the frig?

Yes, you should be.

To answer "how long" you need to tell how big battery bank you're going to carry - this is easy, and what are you other energy uses - this is more difficult for most people.

10-12 cu.ft 120V frig will draw 90-120 AH per 24 hours, more-less. So with one pair of 6V 225 AH batts, even if you have absolutely no other loads - no lights, no furnace, no nothing - you will have to run a generator the next day, and do this for 3-4 hours every day until the end of your stay.

And is the advantage of the residential frig faster cooling?

Not much. My propane fridge is getting noticeably cold inside in about 3 hours, and starts cycling (i.e. the temperature is reached) in 8 hours or less, didn't measure. For boondocking more than a few days this isn't crucial. Another advantage of a compressor fridge - residential or 12V - it doesn't need to be level to operate.

Having said this, I should tell that I want and will replace it with 12V compressor fridge, because my solar is - hopefully - big enough for that, and I can add one more solar panel. The problem with 12V units is 3-fold:
1) A bit of DIY work. You need to install it, and preferably to add insulation.

2) For people that got used to huge fridges in their homes, 12V units are small - hard to find any larger than 9 cu.ft. Those that fit into the cabinet of most common 6 cu.ft propane frig, will also be ~6 cu.ft., or maybe 7.5 if your cabinet is bigger than usual.

3) More expensive than 120V residential. Though not much more. Low-efficiency off-brand frigs from big box stores are cheap. But I tried to find a 120V frig that fits into my cabinet, and most models are either too wide or too deep. Those that are slim, are usually new models, designed for smaller places of modern urban kitchens, and cost upwards of $1,000 or $1,200. For comparison, 6 cu.ft 12V unit would cost 1,400-1,500 and will likely be more efficient as it won't require inverter (plus, there is no high starting current in 12V Danfoss compressor).

Edit- PS:
I didn't notice you said "if I don't have a generator". Stay with standard LP fridge, this is the easiest. If you still don't want LP, and don't want to have a generator, and don't want any DIY, then the only way is to get a VERY small 12V fridge, there are portable models that need no installation. I would still add a small solar system in this case, there are portable arrays under $300. You might also need to increase the battery bank size to 300-400 AH 12V equivalent.

There exists the option of a 12v/120v compressor fridge too. No inverter needed.

These generally are much more expensive than the 120v only residential fridges, but no inverter needed, so there is a ~15% electrical savings right there.

I am not sure how much total difference there would be in battery consumption between 2 equal sized fridges, one residential, and one 12v fridge. I suspect it is way more than the 15% inverter losses, and factor in a little Peukert too.

Perhaps, if less battery, less recharging sources, and less inverter is needed, the cost of the 12v compressor fridge is not any more expensive than the residential 120v only fridge is.

I am rather impressed with my 1.8 cubic foot Vitrifrigo fridge, both as far as internal temperatures and battery consumption.

Anyway, 12v compressor fridges are an option. NovaKool, Vitrifrigo, Isotherm, Waeco are several of the bigger names using the Danfoss/Secop compressors.