Compressor Fridge

[GregWCIL]

Hi Mark,
Our experience with our new 5.0 and compressor fridge may be helpful although it doesn’t include numerical data.
We ordered ours with no solar, no inverter, and only the base 88AH lead battery. This because I am now mounting a large solar array on the roof and associated lithium and inverters.
So our first break-in trip was with the most basic electric. We drove 4200 miles and camped about 20 nights. Several of those nights were without hookups and a couple of times we were off-grid for a day and a half. I’m not sure I ever saw the battery monitor read below half. We had to compressor fridge set on 4 (out of 6). And it kept Ben and Jerry’s rock solid in the freezer. Other electric usage was the lights, furnace many nights and water pump.
I was impressed with the miserly power consumption and it was very very quiet. We lugged a 60 lb. 3000 watt generator over 8000 miles and never used it once.
With solar and lithium I can’t imagine you would have any issues. In lieu of a generator, I would consider a portable solar panel and/or a charge converter to let your tow vehicle help charge the batteries.
Good luck. It’s fun making these decisions.

[Ynnde]

Thanks for the responses everyone, that configuration option is now settled ! And yes I was informed by management that there is a non-negotiable requirement to keep ice-cream at the ready

[CE Vogel]

I have an 8 cubic foot Norcold compressor fridge that draws about 6.5 amps when running. I also have one 180-watt solar panel and three 100 AH lithium batteries. With clear summer weather, the solar panel will just about keep up with the fridge over several days. Your plan of two solar panels plus a portable should be plenty to run a compressor fridge and a few other items.
I very much like my compressor fridge. It gets cold quickly, can keep ice cream and make ice in 100 degree heat, and mine is very quiet. I've had no issues and no complaints.
I think you have a good plan and suggest you go with it.

[drjp]

I totally agree. Wouldn’t use a compressor fridge. Our three way absorption fridge has Really worked well over 14K mostly hot Road miles. Happy with it for sure.

[LSmith]

Just a thought for consideration for emergency charging of batteries. There is a product called Car Generator. It is just an inverter that is supplied with the parts to easily connect to your vehicles electrical system. You just connect it to your vehicle, start the vehicle and plug the load (trailer) in. Your converter then charges your batteries as normal. I built my own setup and tested it at home. It worked fine. It is much smaller and lighter that a generator, can easily be moved vehicle to vehicle, and can be used as an emergency generator at home. While probably not a solution for frequent use, it seems to fit the bill for something that works well for the rare occasion that another charging option is required. Our small trailer only requires 15 amp power. Larger trailers would need an adapter.

[CarinaPDX]

I haven't pulled the trigger on an Escape yet but have 3 decades of living and cruising on a boat (in addition to having built the boat), and recently went camping in my brother's new (to him) RV. The first thing I noted was how sensitive propane refrigerators are to being level - what a nuisance to have to level the RV to within 2 degrees every time. Compressors mostly don't care about heel, certainly not as much as the occupants do. Also, RV refrigerators (all power sources) are very inefficient compared to refrigerators on quality cruising sailboats: the insulation is thin and the doors empty the cold air every time they are opened. Having 4 inches of foam insulation and a top hatch for access would make a world of difference. The closest thing to that would be one of the portable coolers that use the small Danfoss compressor. I have seen some DIY videos of such coolers in campers, strapped into a bay that was custom made, with optional additional foam insulation. I really don't see why manufacturers like Escape don't just build a fridge/freezer with a fiberglass liner and foam under a counter, and install a Danfoss conversion kit. Total costs in volume would be less than buying fridges and I think the power consumption would halve. Anyway, I would go with the compressor approach even as inefficient as it is.

[BobG]

That is what I did back in 2006 or 7 on my sailboat. Built refrigerator in a top load insulated box under the counter with PVC pipe and small computer fan to move air from bottom to top. I used a small Danfoss compressor and a very precise thermostat (to deal with refrigerated medicine over extended time in remote places).
I can see absorption for certain situations but I had no concern going with it on my 2021 21NE because I intended adding batteries and solar.

[Ron in BC]

Originally Posted by CarinaPDX

what a nuisance to have to level the RV to within 2 degrees every time.

. Having 4 inches of foam insulation and a top hatch for access would make a world of difference. The closest thing to that would be one of the portable coolers that use the small Danfoss compressor.

It's not as if you actually have to measure 2*, basically close enough is good enough and the newer fridges aren't nearly as sensitive as ones from yesteryear.

I've had top loading fridges/freezers on two of my boats. One I built a super insulated box and used a NovaKool. Worked well, current draw wasn't bad and my prop shaft alternator had no trouble keeping it charged during long sails.

The other boat had an engine driven compressor with a holding plate. Unbelievable performance and about 45 minutes of engine time would do for over a day as well as charge batteries via a high output alternator.

But it's not about technical performance. Most consumers would find a top loading fridge to be a nuisance and given a choice I think that most would go for the convenience of a front opening fridge/freezer.

Ron

[John in Santa Cruz]

fwiw, I just did 3 full days and nights in a 'dry' campsite with zero sun (giant oak directly overhead and all around), made no special attempt at saving power, it was quite hot each day, even used the inverter to run our electric coffee maker each day, and when it came time to leave about noon on the last day, my batteries were at 50%. By the time I got home 3 hours later, the batteries were at 65% from the solar panel.

Norcold N2175 6.2 cubic foot DC compressor fridge, exact size of the Dometic RMD8555 that died.

[Selkirk]

Just reviving this thread with an additional question:

Has anyone configured their trailer with the 5.5 cuft Norcold DC558 12V compressor fridge with dual 6V lead acid batteries and two 190w solar panels? If so, have you attempted boondocking with this set-up?

I will be starting the configuration process in the not too distant future. I don't think I can justify upgrading to lithium batteries as part of my initial build...but I have been giving more thought to starting out with a compressor fridge.

I will be spending a good portion of the summer season living out of the trailer, but will have access to shore power most of the time....so either an absorption or compressor style would work.

However:

- I'm not all that comfortable with the idea of running on propane while in transit. A compressor fridge seems like a better option....especially now that it sounds like the the absorption fridge options will be 2-way only. I'm assuming that my TV should be able to keep up with the current draw.
- Though I'll have access to shore power most of the time. I do plan on boondocking periodically for a few days, primarily during the shoulder seasons. This means I want a modest amount of off-grid capability (enough for at least the fridge and furnace).
- Eventually, I plan to travel/boondock more extensively. Once I reach that point, I intend to upgrade at least 200ah of lithium.....but likely not for a few years.
- I suspect that the long-term reliability of a compressor fridge will be better than an absorption style.

Thoughts?

[GregWCIL]

Selkirk,
I’m not sure what your solar production will be in the shoulder months but with two solar panels and the 6 volt batteries I’m convinced you will be fine. Our 5.5 Norcold uses very little power.
When we got home from our first long trip I converted my system to lithium (5120 watt hours of battery). Due to health issues I don’t have my solar panels (1200 watts) installed yet. But the fridge, lights and furnace would run for almost a week without charging.
When I finish the system this winter I will do more extensive testing but I feel I will be able to boondock as long as my liquid tanks hold out.
I agree you should go ahead and do the fridge, then update the electric later.
We think we could get a week’s worth of food in our fridge for two of us. It would have been nice to get a larger fridge with two doors but it wasn’t an option. We did gain an extra cabinet above the compressor fridge.
Ps: I did not include equipment to charge the lithium from the tow vehicle. That would extend your electric.

[John in Santa Cruz]

my 360 watt panel can make 2000-2300 watts on a mostly sunny day if the batteries are far enough drained. with my N2175 6.5 cu ft Norcold, my total average daily power consumption is 600-800 watts, that includes furnace at night, fan during the day, lighting, water pump, and miscellaneous DC charging (phone, etc). I would expect a pair of 190W to have similar output. my panels are high efficiency LG NeonR Monocrystalline, with a Victron SmartSolar MPPT 100/30 controller.

I have 2 x 206AH lithiums (5260 watt*hour combined), they will run my rig for 6 days with zero sun (parked in deep shade), and 2 full days of sunshine will pretty much fully recharge them.

[alanerickson]

I have a 2021 E19 w/ the 5.5 compressor fridge, 190w solar on roof, and two 100w suitcases. I have 200 AH of lithium and shunts on both my battery bank and fridge. Graphs of battery state of charge from a weeks long trip are posted on page 2 of this thread.

I'm pretty conservative in my power use and with the fridge and the rest of the camper, 50 AH every 24 hours is needed.

I'm not up on lead acid, but I assume at best they are 100AH. Wired in series to give you 12V, you'll still only have 100 AH (but at 12V, which is what's required)
Correct me if I'm wrong, but lead acid batteries are only supposed to be discharged only about 50%, which means you have enough power for 1 day.

I would recommend you not do this, as it is not enough. If you are in the shade or have a cloudy day, your solar is still probably not going to be enough.

You asked for opinions, and I would say 200 AH Lithium is the minimum you want/need. Closer to what John has would be better.

[John in Santa Cruz]

Golf Cart 6V batteries are true deep discharge, unlike the more typical Marine/RV batts often used on trailers, and they are typically 210-225 AH. GC batts can be discharged to 70 or 75% many 100s of times as they have massive thick lead plates. I would say its safe to get 12V at 220*.7 == 1850 watt hours out of them from time to time, for my Escape 21 w/ the N2175, that would be sufficient power for 2-3 full days with zero sun. I definitely *would* want to have a proper battery shunt meter, such as a VIctron SmartShunt (used with a bluetooth phone or tablet), or a BVM-712 (has its own display)

[alanerickson]

Thanks. I stand corrected on the batteries. Then yes, 2-3 days.

[HABBERDABBER]

Pound for pound, your propane has an order or 2 magnitude MORE energy than any battery. 10X-20X. I've never experienced any safety issues with the refrig running on propane, nor read of any. Sure, it is turned off on a ferry, or tunnel transit, but that's it, and I've been in neither.

Of course, do as you please.

[sunrisetrucker]

There are many good reasons for choosing a 12V compressor fridge but choosing one because you are afraid or nervous of running a propane fridge on propane while traveling is not a good reason. IMHO.

[Mary F]

Originally Posted by HABBERDABBER

Pound for pound, fossil fuels contain 10 TIMES the energy (density) than most batteries. That's a 1000%. Sure, one can run solar, lithium, compressor refrig, but at least for me, my absorption refrig works just fine. I don't have a need for a different set-up given my usage pattern.

Our absorption fridge, in our 2015 Escape 21, will not run on propane if we're camped above 7000 ft. (It isn't designed to run above 3000, so it's "not a malfunction.")

On our recent trip to Washington and Oregon, we were happy to actually use the fridge as designed, instead of as a large icebox. Thus, the prospect of a compressor fridge becomes more appealing, as next summer we'll be reverting to Colorado Rockies camping (mostly above 9000 ft.)

[John in Santa Cruz]

When my RMD8555 absorption fridge was working, I didn't ahve a lot of complaints, it seemed to work even at high elevations... but then its controller croaked, and became unrepairable (no eta on parts, unknown number of parts required to fix), so I got the Norcold N2175 DC compressor fridge in its place. I overkilled my power upgrades but I'm quite happy with the results.

[Selkirk]

Thanks to those who provided input regarding compressor fridge + 6V lead acid batteries + full solar. Fortunately, I still have a couple more months to thoroughly research this potential combination and ultimately reach a decision.