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Fridge advice and guidance.

eXodus said:
pretty simple math.

My 10 cubic 120V fridge at home needs about 1.5 kWh electric / day, Most fridges have about a COP of 2-3. So those are then 3-4.5kWh of heat generated.
Those are 3 kWh of heat you need to move through the A/C requiring you another 1-2kWh to get rid of it.

Sure if your main scenario is - heating - then a interior vented fridge is awesome - it's additional "free" heat. But if you are mostly cooling - it's terrible.

The 12V RV fridges - for example Dometic are designed as drop in replacement for Absoprtion and are venting to the back into the old cavity - so "external"
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Idk about all that. My daily average of my 19cuft fridge is .35kwh. Idk how efficient it is but I can't find any heat source with a flir.

I also don't think it works like that as any cold air that escapes from the fridge goes into the rv offsetting the temp.

I'd think Absorption fridges introduce much more heat than electric into the rv because insulation only helps so much and it literally uses heat to suck cold air out
 
I replaced a 6.5’ Dometic propane with a 9.2’ compressor Nova Kool in the same opening. My energy usage went down!
 
eXodus said:
My Dometic Absorption fridge- properly installed - NOT in a slide out - with side vent in and roof out - is perfectly silent and works in 100F humid heat in Florida and keeps everything frozen at decent constant temperatures. It has some trouble cooling things down when you freshly load it. But as soon as it hits the setpoint it stays there for weeks. It is not swinging more then my regular cheap 120V house switch.
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Mine worked well also until it didn’t.

Had a Keystone 5th wheel and 2 years into having it the fridge coils for whatever reason leaked out.

Replaced with big box fridge because it wasn’t under warranty and replacement was $1500 vs $200.

The problem with that RV was every single time you got in it something was broke and it was usually when you were 50 miles into BFE.

The very first trip we made in it to Pigeon forge the Propane valve that controls which tank is active decided no gas could pass through it no matter what tank we used.

Yea it’s still under warranty if you can find someone that does Keystone warranty then you have to drag it to their shop and wait.

Luckily I went to a big box store and found appropriate piping to at least make it work or we would have had no heat.

Combine that with an hour+ setup / takedown after dragging it through every kiss your butt turn and traffic ,then trying to negotiate parking in a slot with 60ft of truck and RV with trees ,kids, parked cars, assholes staring at you daring you to hit their lawn chair, the leaks, $70 nightly pad charges we just sold it.

Maybe if you were boon-docking it would be worth it.
 
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Nobodybusiness said:
Had a Keystone 5th wheel and 2 years into having it the fridge coils for whatever reason leaked out.
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Quality of RVs is unfortunately a race to the bottom for the last couple of years.

My 20 year old Dometic absorption fridge works perfect. Everything original. I know people in the classic RV circles which have 40-50 year old units which still work.

If my trusty old propane fridge should ever brake, I would likely put in a compressor fridge, I am upgrading solar in the moment and it's getting harder to impossible to find good quality absorption units
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Nobodybusiness said:
Maybe if you were boon-docking it would be worth it.
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That is my preferred way of camping. 80% of our trips are without hookups.
Nobodybusiness said:
Combine that with an hour+ setup / takedown after dragging it through every kiss your butt turn and traffic ,then trying to negotiate parking in a slot with 60ft of truck and RV with trees ,kids, parked cars, assholes staring at you daring you to hit their lawn chair, the leaks, $70 nightly pad charges we just sold it.
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One of the reasons we have 24FT Class A.
Setup time is literarily putting it in Park. About a second. Fits in many parkingspots, many boondocking sites are free or very little cost.

richard cabesa said:
I replaced a 6.5’ Dometic propane with a 9.2’ compressor Nova Kool in the same opening. My energy usage went down!
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Are you referring to 12V energy usage or 120V? 120V would be clear- absorption fridges when run with electric are power hungry. Would be interested in your 12V numbers and how you measured them.
 
eXodus said:
Are you referring to 12V energy usage or 120V? 120V would be clear- absorption fridges when run with electric are power hungry. Would be interested in your 12V numbers and how you measured them.
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12V.
The Dometic used 13 watts continuously to keep its brain alive. The Nova Kool uses 46 watts when running but at about 40% duty cycle that’s about 19 watts/hour. That’s up not down right?


But that’s not all, my RV had an electronic control valve to keep the propane on that used 24 watts continuously
it was close to 75 Ah a day to run a gas fridge..

So I guess I’m cheating when I say the fridge made my usage go down, there was more to it.

Now I’m around 40-45.Ah per day

And, I replaced that stupid valve with a manual one
 
richard cabesa said:
But that’s not all, my RV had an electronic control valve to keep the propane on that used 24 watts continuously
it was close to 75 Ah a day to run a gas fridge..
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that is a ton of power for a valve. The valve for the burner on the fridge needs 0.3A ~ 4W

richard cabesa said:
And, I replaced that stupid valve with a manual one
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mine came with a manual one.
richard cabesa said:
The Dometic used 13 watts continuously to keep its brain alive.
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mine uses about 0.4-0.5A with the burner off and 0.8A when the burner is on and cooling. The LEDs inside need the most power when I am starring at the food and can not decide. ;)

It disappears in all the noise of the other standby draws in my RV. (USB-Chargers, Water Heater electronics, Smoke, CO2 / Propane detectors etc.)
 
As an experiment, I've started turning off the fridge every morning for an hour. Fridge is working fine for now.
.
I'm still thinking I will modify/replace the fridge after we get back home.
 
RoadTurtle said:
My Norcold has turned into a Nevercold :(
.
I'm looking primarily at the conversion kit to add a compressor kit to my existing fridge. Second choice may be replacing the whole fridge with a RV specific 12v compressor fridge. Third choice might be a residential fridge. I'm leaning to 12v over 120v, but shouldn't be an issue managing either one.

Several questions, with the conversion kit, how good are they at holding temps? What is their typical 24 hr run time?

What changes have members of the tribe made, and why did you go with that type?
Not terribly worried about capacity, 600ah battery, 1200w solar.
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Living in a bus 24/7 in Queensland Australia, we tried the "built for motorhomes/boats in hot climate 12v fridge." Lasted not long, couldn't keep up with 40⁰c temps.

Changed to normal residential 240V fridge freezer 5 yrs ago. Still going strong.

I wouldn't hesitate, go the way I did.
 
I understand that a few here detest Samsung but 10 years ago I replaced our 175l 3-way with a 230V Domestic 255l (9 cu ft) Samsung Digital Inverter fridge/freezer.
It is powered by a dedicated US$60 300W 230AC PSW inverter mounted behind the fridge.
Both the fridge and inverter running 24/7 have now survived the rattle and shaking of 10 years full-time travel without a single issue.
No manual defrosting was an added bonus.

For anyone interested the original 3-way devoured a 9kg (20lb) LPG bottle every 10 days.
Here in NZ that equates to almost US$7000 savings so far. Enough to replace our entire now 10 year old solar, LiFePO4 battery, fridge etc. setup - twice!

A 6 month data log from day one showed the average energy draw including inverter losses from our 4 cell battery was almost exactly 800Wh daily or in amps 2.52

The 2 large Dometic external vent hatches were removed and covered with 3mm white polycarbonate sheeting.
 
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justinm001 said:
Absorption fridges... Average consumption is .22kWh/day this week and .34kWh/day for past 30 days. Currently using only 1.5 watts! Past 30 day total consumption is 10kWh.
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umm, Im curious about the math... 0.34kwh/day means how much? You did decimals then use "k" to move decimals and now Im lost.
 
Are there no upright 12v DC fridges that will be similar price? The upright do take up less room than the chest sty bc the door opens into the walking space, not into the cabinet space.
I have a DC chest fridge and will never go back to propane. I put 1.75 inch thick styrofoam insulation around the base and sides (and keep towel on the door) so it is super insulated and runs a fraction of the time, and this makes it really quiet too. Low amp draw as opposed to the cheap dorm fridges too. I have a dedicated battery to it so know exactly how much power it needs, not a lot, and solar on sunny days, it never gets close to needing much battery.
 
I went with a recreation fridge/freezer combo. At first I was hesitant the portable refers wouldn't cool fast enough since there is no fan inside blowing around cool air. I was also concerned about longevity, build quality and energy usage last. There have been a lot of refer failures on reddit and I didn't want that. I found a model that is made of steel and not plastic. The steel is galvanize coated and then painted. Its taken dents and it doubles as a work bench, a seat, stool and many other things.

For efficiency, it can be in 114F heat in the shade and the control knob set to 32F and my steaks will be just off freezing. In the winter I set it to 34F otherwise my steaks freeze. Its pretty amazing to touch the metal case and it being too hot to hold onto, yet my steaks are perfectly cold inside. It has more power than I need.

It runs off of 120V or 12V and 24V with automatic switching. If 120V goes down then it draws from DC and vise-versa automatically. In the hottest of nights it uses less than a 16ah 12V battery. Its pretty efficient using 0.54-2.35 Amps@ 12V. It has one of the most efficient and reliable compressors on the market, the SAWAFUJI. The compressor has only one moving part and that is a single piston. Here are their efficiency graphs.

I looked at competitive fridges and they have bluetooth, wifi, bells and whistles. What I like about the Engel is its super basic in design and features. It hits all the fundamentals. One knob, one light (LED that is always on, no switch to break), stainless steel latches and hinges. The lid will open in multiple ways (requires changing hinges). It was worth the $1,200 a couple years ago when I bought it, now they are $1000.

The drawbacks are its heavier than plastic, its expensive, it only holds 43QT but that was all I had room for.

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justinm001 said:
Absorption fridges take a ton of space for all the absorption part you're losing inside the fridge. I'd definitely go with residential fridge if you leave your inverter on. I have the massive one below and have a smart outlet on it. Average consumption is .22kWh/day this week and .34kWh/day for past 30 days. Currently using only 1.5 watts! Past 30 day total consumption is 10kWh. Don't think the winter matters much as we keep the RV at least 55 inside.

BTW mines fridge only as we have an electric cooler in basement if we want icecream.

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Haaa…love it… that is one serious refer …and 3500.00……..Yeow….that will stroke out some of the folks.

J.
 
richard cabesa said:
12V.
The Dometic used 13 watts continuously to keep its brain alive. The Nova Kool uses 46 watts when running but at about 40% duty cycle that’s about 19 watts/hour. That’s up not down right?
But that’s not all, my RV had an electronic control valve to keep the propane on that used 24 watts continuously
it was close to 75 Ah a day to run a gas fridge..
Click to expand...
My old propane fridge that had no brain, only relied on turning a knob to control a manual gas valve, no DC needed, used 300 amp hours per day, and 17 watts!!! I feel your pain, but not your numbers....

upnorthandpersonal thanks, its easy to get off by a decimal when reading and thinking, lol.​

Watt hours better term, but Im so used to amp hours being used. so your 340 w/h is about 1.5 amp hours per hour (26 amp hours per day), similar to mine, a little more.
Ah = Wh / volts
Wh = volts * Ah
I use 13 volts, not 12, or you can use 13.6 volts if on lithium, 12.5 or just 12 if on lead acid.
 
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justinm001 said:
The only real reason for going 12v over 120v is if you don't keep your inverter on all the time or if you're constantly boondocking with limited batteries and the few percent of conversion losses make a huge impact.

There's 100x more fridge choices and much better quality if you go 120v.
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It was cheaper for us to buy a high quality inverter (Victron 12/1200) and a 7.4cf 120v fridge/freezer, than a DC powered one. The eco mode and 91% efficiency of the Victron nearly make the conversion losses a moot point. It works spectacularly well in our 3-season camp trailer. We paid $250 for the fridge (brand new Avanti brand but at a discount due to a scratch on the side of the unit that is hidden from view) and about $360 for the inverter (open box model, full warranty). DC models started at $1200 for similar size.
 
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I'm waiting for my absorption RV refrigerator to die. At 17 years old, it's days have to be numbered. But it still works.

I looked around for a compressor replacement that fit that exact space. While I'll gain a lot of interior cubic feet, there isn't going to be a huge improvement in the weight. My Dometic RM2852 weighs in at 124 lbs (136 lbs depending what source you look at). The 120v Magic Chef HMDR1000BE for $449 at Home Depot weighs 117 lbs. Minimum weight savings of 7 lbs, max of 19 lbs.
 
HRTKD said:
I'm waiting for my absorption RV refrigerator to die. At 17 years old, it's days have to be numbered. But it still works.

I looked around for a compressor replacement that fit that exact space. While I'll gain a lot of interior cubic feet, there isn't going to be a huge improvement in the weight. My Dometic RM2852 weighs in at 124 lbs (136 lbs depending what source you look at). The 120v Magic Chef HMDR1000BE for $449 at Home Depot weighs 117 lbs. Minimum weight savings of 7 lbs, max of 19 lbs.
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That's the fridge we got. Given that I humped everything into or out of place solo, the Magic Chef is notably lighter.
 
hardtop said:
I went with a recreation fridge/freezer combo. At first I was hesitant the portable refers wouldn't cool fast enough since there is no fan inside blowing around cool air. I was also concerned about longevity, build quality and energy usage last. There have been a lot of refer failures on reddit and I didn't want that. I found a model that is made of steel and not plastic. The steel is galvanize coated and then painted. Its taken dents and it doubles as a work bench, a seat, stool and many other things.
Click to expand...

Some of the recent cheapo miniature fridges have quite decent numbers, this one for example 49kWh/y or 134Wh/day. (european market model)
www.idealo.de

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Bereits ab 197,19 € ✓ Große Shopvielfalt ✓ Testberichte & Meinungen ✓ | Jetzt Klarstein Happy Hour 45 l günstig kaufen bei idealo.de
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Coupled with dedicated inverter that runs only on demand you should be able to get around 12-15Ah per day.
 
MattiFin said:
Some of the recent cheapo miniature fridges have quite decent numbers, this one for example 49kWh/y or 134Wh/day. (european market model)
www.idealo.de

Klarstein Happy Hour 45 l ab 197,19 € | Preisvergleich bei idealo.de

Bereits ab 197,19 € ✓ Große Shopvielfalt ✓ Testberichte & Meinungen ✓ | Jetzt Klarstein Happy Hour 45 l günstig kaufen bei idealo.de
www.idealo.de www.idealo.de
Coupled with dedicated inverter that runs only on demand you should be able to get around 12-15Ah per day.
Click to expand...

This can be tricky to accomplish. The fridge thermostat needs AC power to trigger the compressor. The nature of the "ECO" power signal and the trigger points may not allow it to function.
 
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