fridge: propane vs watts

baddawgz

I am new to this discussion but not to solar as my ranch has been solar powered for over ten years..this is what I learned from personal experience..propane sucks...its expensive for a fridge..too problematic...dangerous...costs too much...etc, etc. the last time my propane regulator took a dumper it toasted the fridge from overpressure/too many btu's.. I started looking at online ads for rv fridges and solar compatable fridges all in the $1000+ range...after living out of a cooler for 3 summer months I was not a happy camper believe me...a friend called me one day asking if I was still looking for a fridge and advised me he was at home depot and there was one there that used 300 watts of 120 v for $199....! Long story short...I bought it, brought it home and its been keeping my beer (and other things) cold for three years without a freakin' hiccup...its running on a $139 12v harbor freight modified sine and I wouldn't trade it for any gas fridge anywhere in the world..its a magic chef 11 cubic ft. or so apartment size unit that is now just over $200...propane fridge makers ..KMAAGAL (kiss my *** and get a life) ....$200 ..! crap... I spent that much going for ice...

icarus

Re: fridge: propane vs watts

Here is my take on the Propane/conventional fridge issue, from someone that has used propane fridges since they were kerosene!

The cons of propane:

They are expensive to buy, they can be quirky, they are small by comparison, when the cooling units fail, they are generally not cost effective to repair. They need to be seviced (burners cleaned once a year or so) Propane fuel continues to get expensive. They are slow to cool upon lighting.

The pros of propane:

They are easy to install off grid. For a seasonal or part time dwelling or RV the cost wins hands down IF you figure the added PV system cost involved to run a conventional fridge. In an camper/RV setting they can run off of LP or 120vac or some even off 12vdc while traveling. Once you understand them,, they are reliable, and their quirks are simple once you know them. My neighbour has a Dometic that has been running on LP continuously for 22 years, with only the occasional burn cleaning! Show me a compressor fridge that will do that. If you add insulation (foam board) to the outside of the cases, and have good ventilation over the coils (fan assisted is best,,, coupled with intake and exhaust vents to outside) they can be quite efficient on a per BTU of propane. Mine uses 1500 btu/hour,, (~0.018gal) and runs ~ 4-6 hours/day on average,,, (.072-.108 gal) per day,, at $4/ gallon it cost me ~$.28-.40/ day. Not an insignificant cost.

Conclusion:

As I started with,,, if you are full time,,, and you buy a good energy star rated conventional fridge you will pay less than a (smaller) LP fridge. You would have to have ~500wh of panel/battery/inverter per day capacity to run it, something like 3-500 watts of PV,,, costing $2500 to buy maybe? Paying off in ~ 3 years. ($2500X $.40=1000 days)

If you are part time,, let's say you use it 60 days a year,, 60X .40=$24 It would take 104 seasons to pay off.

So that is my conclusion. I run propane since that is what I have always run. As I have stated often before,, if I had to do it over again,, I would opt for a conventional for full time.

Tony

dwh

Re: fridge: propane vs watts

baddawgz wrote: »

.its a magic chef 11 cubic ft. or so apartment size unit

I'm guessing that is a typo that is supposed to be "1.1 cubic feet".

When I saw "$199", "300 watts" and then "11 cubic ft." I just about choked on my coffee.


As regards RVs - there are two other factors which I've noticed that is are serious considerations in my book.

I've recently purchased a Class B RV (my 4th RV, I've had two Class Cs and a Class A previously); it started life as a Club Wagon 12-seat window van, and the doctor who owned it (original owner) decided at some point to take it in and have it converted to a fully self-contained motorhome.

Sometime later he died, and the truck sat in the driveway for 15 years. The widow finally decided she wanted it out of there and put it up for sale. No one was interested of course, since it had sat for so long. I could tell that the doctor was a man who did proper maintainance, and except for 15 years of dust and a scabrous paint job, it looked in really good shape. Only 84k original miles as well. I offered the widow 200 dollars and she took it.

Unbelievably, all I had to do was put in a new engine battery and some gas, top off the oil and trans fluids (1 quart each) and air up the tires and it started right up and I drove it home.

(And completely unbelievable, yet true - the RV/Marine house battery was still topped off with water when I checked it (I was going to disconnect it so the engine charging system wouldn't choke on it), and IT TOOK A CHARGE! And it's STILL HOLDING A CHARGE! After sitting for 15 years....weird!)

Anyway, back to the fridge subject. It's got a 1.7cu' Norcold 3-way, which I haven't yet turned on (can't trust the propane system at this point).


Now to my original point:

A) Propane fridges have to be LEVEL. I think within 3 degrees of level or so. Compressor type fridges can be safely operated without worry at something up to 20-25 degrees off level.

Since I'm the type of camper who tends to explore up fire roads and then camp at the top, being level isn't always (or even usually) an option.

Propane is "supposed" be turned off when the vehicle is moving. I know many (or maybe most) people don't bother to shut off their main valve and switch the fridge to electricity before they drive, but legally they are supposed to. And there is a good reason for that law.

This little Norcold uses 11.2 amps on DC! Wow! If I switch to DC and then arrive at a campsite and forget to switch the thing to propane, it's going to eat my battery alive.


Norcold makes this same size fridge in an "electric only" model, and that fridge only uses 3.5 amps running on DC.


So, for these reasons I'm almost certainly going to replace the fridge with a non-propane unit.

icarus

Re: fridge: propane vs watts

DWH,

You are right,,, and wrong about a couple of things.

First on the level issue,, you are absolutely right that the fridge needs to be level while running, EXCEPT while on the move. The fridge works with gravity and the motion actually helps the coolant circulate, and it doesn't matter if it is off level while under way. Parked out of level (reasonably) with the fridge running is a recipe for blowing the cooling unit. The reality is,, if you are parked so that you can comfortably live,, you are probably close enough,, especially in the left/right dimension. Front and rear doesn't matter much.

Second,, you are also right about running a fridge on LP while under way,,, although people do it all the time,,, I don't recommend it. On the other hand,,, under way an 11 amp (12vdc) (~135 watts?) is not really a big deal if you charge from the vehicle, and change over once you park. You can (and should) relay control the supply for the fridge so that it can't run on the vehicle battery unless it has a charge source, to prevent killing the battery.

I personally don't think it would be cost effective for you to trade yours out,,, but if you do I might make you an offer on the NorCold. LOL. NorCold's have a pretty good rep for being bullet proof,, but I have never had one.

Tony

dwh

Re: fridge: propane vs watts

icarus wrote: »

DWH,

You are right,,, and wrong about a couple of things.

That's not at all unusual.

First on the level issue,, you are absolutely right that the fridge needs to be level while running, EXCEPT while on the move. The fridge works with gravity and the motion actually helps the coolant circulate, and it doesn't matter if it is off level while under way. Parked out of level (reasonably) with the fridge running is a recipe for blowing the cooling unit. The reality is,, if you are parked so that you can comfortably live,, you are probably close enough,, especially in the left/right dimension. Front and rear doesn't matter much.

A couple of points:

A) I was looking for a class B because I will mostly be camping solo (was a single father for 18 years but my son is grown now) and wherever I go I'll have a small tent and sleeping bag with me and I'll be comfortable even if the vehicle is hanging sideways off the mountain (and it might well be, the way I drive).

The fridge is mounted to face the centerline of the vehicle, so front/back and left/right are rotated 90 degrees from what they would be in a building.

Second,, you are also right about running a fridge on LP while under way,,, although people do it all the time,,, I don't recommend it. On the other hand,,, under way an 11 amp (12vdc) (~135 watts?) is not really a big deal if you charge from the vehicle, and change over once you park. You can (and should) relay control the supply for the fridge so that it can't run on the vehicle battery unless it has a charge source, to prevent killing the battery.

Not only is it not recommended to have the main valve open while underway, it's against the law in most places.

Yes, I'm fully aware that the electrical load of the fridge is a non-issue underway. I haven't checked this one yet, but I've owned half a dozen vehicles with the 460 engine and all had either 40a or 60a alternators.

Sure, switching over is no problem - as long as I remember to do it. Which, inevitably, at some point I *will* forget to do. The relay is a good idea if I were to keep the fridge, since it would protect the battery from drain, and I suppose it wouldn't hurt to have the fridge non-functional until I remembered to open the main valve on the propane and light the pilot.

I personally don't think it would be cost effective for you to trade yours out,,, but if you do I might make you an offer on the NorCold. LOL. NorCold's have a pretty good rep for being bullet proof,, but I have never had one.

Tony

Cost effectiveness isn't the highest priority in this case. I'm more interested in reliability, and "must be level when parked" is an issue. I may not go with the Norcold 1.7cu' replacement either. I've looked at lots of little fridges, not just RV types. Also, I might decide I'd like to have a freezer section and might go up to a slightly larger unit - the cabinet does have room for me to cut a few inches out of the top of the fridge section, though I couldn't go any wider.

If I decide to replace this unit (I've pretty much decided already, but I'm not in any hurry) then certainly, I'll give you first right of refusal on buying it.

First though, I need to go through the propane system and bring it up to snuff. I know it'll need the rubber lines replaced (two) and all the connections soap-bubble tested - and I'm going to toss the single-stage regulator and put in a dual-stage. Only after that can I even see if the little fridge works (on propane that is, I could check it with electricity right now, but I won't until I first checkout the propane system so...).

The truck is in good shape inside, but the outside is heavily weathered - and the back of the fridge can be considered to be outside due to the roof vent and the access panel through the wall of the vehicle. It's not been in the rain or anything like that, but from what I can see through the access panel, there is a not inconsiderable amount of surface rust on the works.

baddawgz

Re: fridge: propane vs watts

Icarus,with all those calculations you must be a bean counter so count these.... $1800 for 750 watts of kyocera's, $400 for 4 50 watt panels...$250 for 50 (yes 50) trojan golf cart take out bats...$139.50 1500 w inverter..recycled 10 ga. house wireing... steel scrap for panel construct....no trips to town for propane...yadda yadda yadda.....Been there done that... had my lungs fried by ammonia in the middle of night...paid for three new whatevers ($300 a pop) on a dometic that I finally took out in the desert and shot, to put it out of MY misery...so some guy had a dometic for 22 years and never had a problem..! how much ice did that make in a day...? not to mention he must have had Jesus and the twelve praying over that Dometic...I have to say that I really don't give a rats you know what for any fridge that has the problems associated with propane and the ammonia/absorb system... I have owned three dometics and one Sibir.. when the Sibir went south no one even fixes them..so hello/goodbye $1500+....I have a camper size dometic sitting here that I will give away free to anyone that wants to come to Tucson and load it up...Sibir too...they are too problematic for me my friend...I will give you the fact that in some circumstances they are neccesary as in RV'ing and it looks like you are not needing a bailout loan to keep your cool going on...the new koolatron type has some promise and somewhere I read about a patent using sound of some type to make cold a few years ago....I thought that doubling up a koolatron unit in one case might even keep a beer cold enough to drink without puking...haven't seen one yet tho...

DWH...Roger...that is 11 as in ELEVEN CUBIC FEET.. AS IN 23" wide 23" deep And almost 5 feet tall...BUT for your RVing go with that 3.5 amp deal..it sound like a koolatron type as thats the amps that they draw...Hey that battery still holding a charge after 15 years...wow..? My golf cart take outs should be good for that ...right Icarus...? be a good sport and be sure and factor that in my cost analysis will ya buddy....? DWH I love your avitar, avatar, avatwirp..oh whatever...very very kool...!!!

Cariboocoot

Re: fridge: propane vs watts

I had propane, replaced it with electric. The 'frige is 16 cu. ft. Frigidaire and it cost less than $500. Uses 240 Watts +/- during regular cycle, a nasty 500 W on defrost.
My meager 700 watts of panels have no trouble staying ahead of it and most of my other electric use on a good day. This is run off a pure sine inverter; the motor 'rattled' a bit on MSW, but worked. I needed PSW anyway for other equipment so ...

Anyway, dropping the propane unit saved a LOT of propane, plus we now have larger refrigerator/freezer capacity. Like Tony/Icarus said; it depends on how much you plan on being there.

Incidentally, it takes about 3 hrs for the electric refrigerator to cool down from room temp. The propane one took almost twice as long.

dwh

Re: fridge: propane vs watts

baddawgz wrote: »

DWH...Roger...that is 11 as in ELEVEN CUBIC FEET.. AS IN 23" wide 23" deep And almost 5 feet tall...BUT for your RVing go with that 3.5 amp deal..it sound like a koolatron type as thats the amps that they draw...Hey that battery still holding a charge after 15 years...wow..? My golf cart take outs should be good for that ...right Icarus...? be a good sport and be sure and factor that in my cost analysis will ya buddy....? DWH I love your avitar, avatar, avatwirp..oh whatever...very very kool...!!!

Yea, 11cu'. I had a brain fart and was thinking that was huge. Then I remembered when I bought my mom a new top of the line fridge from Sears for Christmas one year and it was 23cu' - so all I can say is woops.

The 3.5a fridge I was referring to is an RV fridge. Either Norcold or Dometic I think. Can't remember exactly since I've looked at the specs on fridges until my mind is mushy.

Yup, a 15 y.o. battery. It was still full to the top when I checked it before I started the truck, so I left it connected (had to see what would happen doncha know). It charged up some when I drove the truck home, and I've driven it to the tire store (had to toss out a brand new set of top grade Goodyear tires that were age cracked...boo hoo) and the smog shop (it passed) and the RV place since and the battery seems to be working fine. I had the inside lights on (4 fixtures with single 1141 lamps) for a few hours one night while I was poking around the truck and they never dimmed. I finally remembered to check the voltage a couple of days later and it was at 12.8.

I haven't bothered to put it on a charger as I'm planning to replace it anyway. I found a place around here that can sell me a new Deka 105ah for about 150 dollars that will fit in the house battery space under the hood.

baddawgz

Re: fridge: propane vs watts

Oh ya..I forgot to mention to Icarus that as a kid we had a old GE fridgedair compressor type that my folks used for over 30 years before giving it away...and it still worked then...go figure...Hey I noticed you have a honda gen. ? I had one go south on me in a way that was preventable if I would have known what was up...the carbon brushes have a retainer that as they wear down will eventually keep the brushes from contacting the armature then the amp flow will start jumping the gap and arcing frying the armature beyond repair... clever little trick Mr.Honda uses to increase sales..pays to check them occasionly by seeing how much brush is left..$30 or so for brush set will save a bundle on new gen...

icarus

Re: fridge: propane vs watts

No,

I'm not a bean counter,,, not that hot with math.

I just feel that the purpose of this forum is to put forth real world idea/experiences. You had a series of bad experiences with Propane fridges,,, I just wanted to illustrated that I have had 50+ years of pretty good experience with LP fridges. I do know the quirks,,, having been brought up with them. As you suggest,, other's mileage may vary.

I go back to the beginning,, you sort of have to know what you are getting into with either choice. I stand by my original posit,,, that if you are only going to use a house/cabin etc seasonally,, and you are on a budget propane does have it's virtue.

Additionally,, used propane fridges are pretty reasonable if you shop well. Beware however that used ones may have problems. Out of RV's they often can be had pretty cheap,, or free,, like yours.

Tony

baddawgz

Re: fridge: propane vs watts

Ya, I understand totally..its like me and General Motor cars..I never ever, ever EVER buy one because the minute I get in it things start to go south ..anything else ..no problem...
I agree that on a seasonal basis they would be the drug of choice.. once the propane is off , its off ..where thats certainly not the case with solar ..

Math is not really my strong suit either..without a calc just call me Homer..here in the southern AZ its usually sunny AND hot..I have two Computor fans blowing over the condenser in the back during the summer..it's great to not breathe the fumes from the in house fridge (I had it on the porch but the illegals would steal the food out of it) like I did for a while..I got some dogs and the food was still being stolen so I got more dogs...it took 10 dogs to secure the fridge on the porch then they started getting in it and I moved it inside..finally the Sibir died and I switched to the Magic Chef...
I won't be shopping for any believe me..
It looks like you are in the northwest by the pic..? anywhere near the fair isle of Vashon ...?

baddawgz

Re: fridge: propane vs watts

DWH
I have those all the time...I used to rv on remote areas for a lot of years and one year I bought a little rig that a guy was making and selling for 100 bucks..it was a briggs and scrapiron lawn mower 2 1/2 horse engine with an 12v automotive alternator running off a belt on the engine pulley, both bolted to a pice of 3/4 plywood... the regulator was a coil of wire tacked down to the plywood and depending on where you placed the alligator clip on the coil it would vary the + voltage to the field terminal and vary the amps charging the battery..the thing would sit running at idle and charge 10 to 15 amps...the guy sold all he could make..I used mine for a couple years to charge the rv bats until the briggs wore out finally and used so much oil I s-canned it..it was very cool...! a lot of people on the mine were running gens at 3500 rpms to charge 8 amps 12v using tons of gas and this little briggs was just putting along a little above idle to pump 20 amps in..amazing..