Here's how I've been using my propane fridge...How do you use yours? Should I change?

[TMG51]

Okay I've had a couple threads about refrigerators already, but this one isn't for specific technical information but rather to get an overall feel for how people use their refrigerators / what expectations I should have.

Basically, the propane fridge I have in my van works but it's 16 years old and I suspect it doesn't work well. The only part that really gets COLD is the freezer. So that's where I put my drinks. I might crap in the woods, but having a cold drink throughout the day is one amenity I will not do without. But the freezer is small, doesn't hold much, and will freeze liquids after a few hours, meaning I have to cycle what's in there and can't keep any frozen food.

Generally what I do is this: Put 2 bottles of water in the back of the freezer and leave them there. Allow them to freeze if they get that cold because they act as a buffer. I can fit 4-5 other drinks (soda, beer) in front of the water bottles. When I remove a drink I replace it with another (warm) one, and pay attention to which has been in longest, so that I'm getting a cold drink but nothing is left long enough to freeze and explode.

The rest of the refrigerator never gets cold no matter what I set it to. It gets kinda cool-ish.... but I'd say the sort of cool you might get from a root cellar. Not cold. So I can't keep mayonnaise/milk/any food items that will spoil within a day.

At night I shut the fridge off because otherwise the items in the freezer would get too cold and explode. I leave it closed up and they're still cold for the morning. I could remove the items from the freezer and leave it on, but then nothing would be cold anyway.    So the items that are in the fridge get cycled from root cellar temperature to room temperature daily. Definitely can't preserve any food that would spoil this way.


So I guess what I'm asking is.... Are these sorts of limitations par for the course or should I be thinking about seriously upgrading my refrigerator? I definitely don't have anything close to the experience most people are accustomed to a home refrigerator. I can't just put something inside and expect it to stay cold a few days. It requires some tending to on my part. But, I do have cold drinks throughout the day and I'm not fussing with ice, so I could see myself going on this way and being okay.

If I were to get into a 12v fridge it would mean more batteries and solar plus the cost of the fridge. So $1,000+. I currently have 200w of solar and one 12v house battery.



But back to the question at hand - what are your refrigeration experiences like? Is it more like a "home" fridge where you can just put something in and leave it or is it some variety of a maintenance point? Also please include whether you have a propane fridge, a 12v compressor fridge, or one of those 12v plug-in cooler thermo-whatever type jobs (not compressor).

 

[Willy]

Any rig I bought with a propane fridge installed I ripped out the fridge and sold it on Craigslist for abt $150. I also picked up both the Waeco and Engel chest fridges for less than 1/2 list on CL. Also picked up a Waeco CR-50 on CL for $220, but prefer the chest style.

 Unless you've got some mighty thirsty stuff plugged in, 200W is plenty.. and I've gotten by with considerably less. Check out on Amazon for a dual battery charge controller HERE which would enable you to use different capacity batts. That would enable you to utilize, let's say, a deep cycle on one circuit and a cheap automotive on the other if strapped for cash. I was using the same controller for a couple of years (still have it) before I picked up an MPPT controller (just to see how much 'better it is and cuz the rig I had didn't have room for more solar). I had 1 battery dedicated to the fridge only and the rest running off the other one.

  Depending on what capacity you require, chest cooler/freezers can be surprisingly affordable, Waeco for example. ..Willy.

 

[TMG51]

Any rig I bought with a propane fridge installed I ripped out the fridge and sold it on Craigslist for abt $150. I also picked up both the Waeco and Engel chest fridges for less than 1/2 list on CL. Also picked up a Waeco CR-50 on CL for $220, but prefer the chest style.

 Unless you've got some mighty thirsty stuff plugged in, 200W is plenty.. and I've gotten by with considerably less. Check out on Amazon for a dual battery charge controller HERE which would enable you to use different capacity batts. That would enable you to utilize, let's say, a deep cycle on one circuit and a cheap automotive on the other if strapped for cash. I was using the same controller for a couple of years (still have it) before I picked up an MPPT controller (just to see how much 'better it is and cuz the rig I had didn't have room for more solar). I had 1 battery dedicated to the fridge only and the rest running off the other one.

  Depending on what capacity you require, chest cooler/freezers can be surprisingly affordable, Waeco for example. ..Willy.

I guess it sounds like you're saying these all just work better than the propane refrigerators.

I admit it would be nice to have something that's cold all the time like a home refrigerator!

 

[Willy]

With an absorption fridge, propane you keep paying for (and kill your battery if set to 12v), while struggling to get temps down low. A 12v compressor fridge, after the initial expense, doesn't cost anything if you already have sufficient solar. It can also work at up to a 30 deg angle and is also MUCH safer, since no open flame or gas leaks. Don't have to turn off to fill up at the gas station and no pilot light to blow out.

These days there really isn't much of a reason to use other than a compressor fridge and replacing one is basically a plug 'n play proposition. I rapidly became disenchanted with absorption fridges, as are a number of people I know, and find the compressor style to be superior for my uses. I sold my Waeco to my buddy Nick when I bought the Engel, and he totally loves it (after he too used an absorption fridge). Beer is ALWAYS cold.

A few years ago the rearend of the truck I had at the times ate the crown gear. So, I stuck it in storage (Osoyoos, Okanagan during the summer and boiling hot) and headed down to the coast to get another one. My Waeco was in the camper I had on the back with abt. 50W of solar and a deep cycle batt. It was fulla frozen meat and I only got back about a month later. The meat was still frozen solid. ..Willy.

 

[BC Guy]

You can get a propane fridge serviced. I have no idea what it will cost as a relative did mine. It did run better afterwards.

 

[jimindenver]

The normal way to run a gas fridge is to start it a day ahead and then make sure you put cold food in it afterwards. They take a long time to recover from being heated up. (warm food, open door)

Sometimes we find out that we can take a trip at the last second. What we do then is start the fridge and put frozen bottles of water in it. It takes a few hours to get the food and pack up, not enough time for the fridge to be ready but the ice bottles act as a cooler until it is.


have you left your fridge on to see if it will get cold over time? Make sure you check the flue for any obstructions that would block the heat coming off of the burner. As mentioned it can be serviced, it may be worth looking into. I was in school for refrigeration and when a gas fridge came in we turned it upside down for 24 hours. Long story short running them unlevel can cause a blockage. Turning them over can help clear it but once the process has started, you will eventually need a new fridge.

 

[SternWake]

Absorption fridges can certainly have their issues.


The freezer portion might be cold enough to freeze, at sub 32f, but is it near the 0f it should be at?  If the fridge portion is in the mid 50's then it is likely the freezer portion is not as low as it should be either.

Running the Abs fridge off level for longer periods of time causes the refrigerant to not flow as well as it once did.  Think of it like heart disease.  It is cumulative, but instead of cholesterol causing it, it is off level running.

The propane burners get clogged over time and the flame is not the size it should be.  Changes in elevation can also cause the flame size to be outside of the sweet spot, negatively affecting refrigerant circulation.

Every summer on other RV forums people complain their absorption fridges are not cooling well enough.  The usual recommendation is the addition of fans to remove the hot air. Some people go well overboard on this, when all that is required is a low and slow and quiet computer fan pulling out the hot air from the highest point behind the fridge, as opposed to 3 fans inline pumping in cold air at the bottom, with no shroud.  With a shroud they would be more effective, but without a significant portion of the  air moved  by the impeller does a U turn and goes through the fan again.

The installation of the fridge is paramount too.  There is not to be large amounts of open space behind the fridge.  About 1 inch should be the maximum, as then the heat rising causes convection currents and air to move naturally over the fins.  The fans should be considered as only necessary in hot ambient temperatures to assist this convection.

If there is too much space behind the fridge, the heat just accumulates.  It akin to trying to cool off by sitting in a car in direct sunlight with the windows closed, as opposed to a moving vehicle with the windows open.

If there is a roof vent, these often get obstructed by wasp or spider nests.  Santa got stuck in the chimney.

Absorption fridges can work very well when all their little idiosyncrasies are attended to and negated, but the owner needs to be aware of them and not rely on proper installation from the factory.  I've seen some incredible examples of ineptitude on factory installs on RVs.  It is as if the workers are smoking crack, and the managers are smoking meth whilst the salesman practices their shark like smiles in the mirror and wipe the cocaine from under their noses.

The 12v compressor fridges have gotten very good and very efficient, but they are also pricey.  They can cool down in 30 minutes, and can keep food safe in 110F ambient temps, but they require the user to have enough charging sources to offset their usage and still fully charge the batteries , or as close as often as possible.  They also require their cooling units be properly ventilated.  Again, do not think the factory cared one whit whether this requirement was met if a compressor fridge came with the unit.

Even most stick and brick fridges are not ventilated properly.  I helped my friend move, and the back of his fridge looked like the lint screen in a clothes drier.  'Gee I was wondering why it was always running!'

Interior fans blowing at the fins can reduce ice build up on the fins.  People look at ice build up as a good thing, but the ice is impairing the cooling unit from extracting heat from the box.  A defrosted fridge is significantly more efficient than one whose evaporator plate is covered in a thick layer of ice.  People often think of fridges forcing things to be cold, when the fridge is actually removing heat from within.  Anything that impairs this heat extraction affects performance, and Ice on the evaporator/ cold plate impedes this heat transfer.

Never use a tool  more aggressive than a fingernail to remove this ice buildup.

Ice build up in humid environments occurs quickly.

Get an Ir thermometer and shoot it at various locations in fridge and freezer.  the freezer should be close to or below 0f and the fridge should be no warmer than 41F, and preferably closer to 30F.

Without an internal fan, my small 50 liter.1.9 cubic foot fridge varied from 26.5f to 44.5F moving the IR gun around.  After installation of a 40MM 0.03 amp 6.3CFM computer fan this narrowed to 29 to 33.5F.  It also allowed me to lower the t stat setting from 4 of 7 to ~2.2 of 7 to maintain that sub 33.5f internal temperature.  This does not use less battery power, just that Warm items placed within are cooled down faster, and much more even internal temperatures.

If one's absorption fridge is not performing properly, ventilate the area behind and above it, or make sure the ventilation that already exists is not obstructed with dust cobwebs or mud dauber nests.

If ones ABS fridge internal fins are covered in ice, defrost it and consider aiming a fan at them.  There are alkaline D cell internal fans available whose batteries last about 6 weeks.

The burner can get clogged as well leading to an inefficient flame of the wrong size or perhaps misaimed too.  Cleaning these can be a simple, but I have not done it myself, but there are likely U tube videos showing how to do it.

Don't accept substandard fridge performance.  One can only expect so much cooling from an absorption fridge, and be patient when it is first turned on or warm items placed within, but if one needs to put drinks in the freezer to be palatable, then something is not right. 

Is  Acceptance of 'not right' OK?  

Check the simple things first, and if they have little or no effect, the refrigerant path is likely obstructed and there is no cure for that besides replacement.  
When replacement is the only option, then you choose one of 3 routes.  Residential fridge on inverter and a significantly larger battery bank and charging sources, another absorption fridge subject to the same idiosyncrasies, or a DC compressor fridge and the increased battery capacity and charging capacity required to keep it running, which will be about half that is required to power the residential fridge on an inverter.

None of the 3 options are inexpensive, and the one option that appears the least expensive initially, the residential fridge on an inverter, winds up costing the most, if one lives on battery power.  If one gets to spend most of their time plugged into the grid, then the residential fridge route makes the most financial sense.

 

[highdesertranger]

well Stern covered it all pretty well, I think the only thing he left out was the locust. you know locust must be involved somehow. highdesertranger

 

[coolmom42]

Okay I've had a couple threads about refrigerators already, but this one isn't for specific technical information but rather to get an overall feel for how people use their refrigerators / what expectations I should have.

Basically, the propane fridge I have in my van works but it's 16 years old and I suspect it doesn't work well. The only part that really gets COLD is the freezer. So that's where I put my drinks. I might crap in the woods, but having a cold drink throughout the day is one amenity I will not do without. But the freezer is small, doesn't hold much, and will freeze liquids after a few hours, meaning I have to cycle what's in there and can't keep any frozen food.

Generally what I do is this: Put 2 bottles of water in the back of the freezer and leave them there. Allow them to freeze if they get that cold because they act as a buffer. I can fit 4-5 other drinks (soda, beer) in front of the water bottles. When I remove a drink I replace it with another (warm) one, and pay attention to which has been in longest, so that I'm getting a cold drink but nothing is left long enough to freeze and explode.

The rest of the refrigerator never gets cold no matter what I set it to. It gets kinda cool-ish.... but I'd say the sort of cool you might get from a root cellar. Not cold. So I can't keep mayonnaise/milk/any food items that will spoil within a day.

At night I shut the fridge off because otherwise the items in the freezer would get too cold and explode. I leave it closed up and they're still cold for the morning. I could remove the items from the freezer and leave it on, but then nothing would be cold anyway.    So the items that are in the fridge get cycled from root cellar temperature to room temperature daily. Definitely can't preserve any food that would spoil this way.  


So I guess what I'm asking is.... Are these sorts of limitations par for the course or should I be thinking about seriously upgrading my refrigerator? I definitely don't have anything close to the experience most people are accustomed to a home refrigerator. I can't just put something inside and expect it to stay cold a few days. It requires some tending to on my part. But, I do have cold drinks throughout the day and I'm not fussing with ice, so I could see myself going on this way and being okay.

If I were to get into a 12v fridge it would mean more batteries and solar plus the cost of the fridge. So $1,000+. I currently have 200w of solar and one 12v house battery.



But back to the question at hand - what are your refrigeration experiences like? Is it more like a "home" fridge where you can just put something in and leave it or is it some variety of a maintenance point? Also please include whether you have a propane fridge, a 12v compressor fridge, or one of those 12v plug-in cooler thermo-whatever type jobs (not compressor).

Your freezer should hold around zero.  The refrigerator portion should hold in the mid-30s. 

There should be a sensor directly below the fins in the refrigerator part.  Check that it's there and check the position.  Check for obstructions in the vent and extra space at the back.  The fridge also has to be level from left to right, and to some extent front to back, to work correctly. 

Take everything out of the fridge and LEAVE IT CLOSED AND TURNED ON for 24 hours.   Do not put anything in the fridge until it is fully cooled down.  After 24 hours running empty, check the temps. 

If it's not good in 24 hours, do the following:

Check the vent for obstructions.  Check the air flow and the space in the back.  Try adding a fan if the space isn't good.

Your fridge should function just as well as a residential fridge.  It will warm up fairly quickly when the door is opened because it loses a large portion of the cool air because it is small.  But otherwise it should function well.  If it doesn't, there is something wrong with it.

 

[DannyB1954]

I was told that sometimes an absorption refrigerator can be rejuvenated by taking it out and turning it upside down for a day. Then right side up for a day before turning on.
In theory being that the chemicals become separated, and turning it upside down helps remix them.

I can't say for sure this works, but what do you have to loose trying it? Also if you can freeze water jugs, put the frozen ones in the refrigerator, and freeze some more. Check the door seal. Make certain it seals well.

I used to live on a boat. my refrigerator had 4" of foam insulation and a compressor system like this company sells. http://www.novakool.com/products/conversion_units.htm
It was a top loading refrigerator, so when you opened it, the cold air stayed inside.

 

[eDJ_]

Turning absorption refrigerators upside down used to be common practice.  

Last time I saw it being done I was at an Antique Store a friend of mine used to visit.   They had an old timer there who had to be in his later 80's  instructing a bunch of young guys on turning this old "Servel" refrigerator on to it's top so it would be upside down. 

It seemed that they came by these at this store as people would contact them and ask what they would give them for it.   Basically they didn't know this old trick for "stirring" the chemicals up to rejuvenate it's cooling
ability.

[video=dailymotion]



Since then I've heard of people with RV's who take them in for service and the service dept removes the
refrigerator and inverts it and then replaces it and lights the propane flame to restart the refrigerator.
Once it is good and cold they call the customer to come pick it up.

Here is a thread in a Winnebago RV board that talks about this inverting technique referred to as "Burping" the system.  (it may take more than once over a period of days)

 

[eDJ_]

Well, it seems the link didn't copy in the last post so here it is again.

http://www.classicwinnebagos.com/forum/index.php?topic=2004.0

 

[DannyB1954]

This person is wrong.  
At the beginning he says a conventional refrigerator adds cold. No such thing.

I worked transport refrigeration for 30 years. Heat is energy. You can not destroy this energy once it is created, you can only move it to a different location. You can not add less energy to something. You can move this energy to something that has a lower level of that energy. The evaporator inside of the reefer has less heat energy than the air inside of the box, so heat moves into it. The condenser outside of the box has more heat energy than the outside air, so the heat moves out of the condenser. As it does so, the gas inside changes back to a liquid. This is referred to as the latent heat of condensation.

The laws of thermodynamics states the heat moves from a warmer to colder substance, (not vice versa). The greater the temperature difference, the faster it will move.
A refrigerator does not destroy heat. it only moves it.  It takes it from inside the box and moves it to the outside of the box. When you put an ice cube in a beverage, you are not adding cold. The heat from the drink goes into the ice. That is what makes the ice melt. The drink got colder, but only because the ice cube got warmer.

 

[highdesertranger]

very good Danny. most people I try to explain this to say I am nuts. highdesertranger.

 

[eDJ_]

That's a good point Danny !   He seems to have gotten it right initially with his explanation of the absorption refrigerator where a cold evaporator coil placed in a freezer or refrigeration compartment provides a source
for the heat energy of food items within those compartments to be drawn to the cold evaporator coil.

Then it goes haywire by defining the Home Refrigeration as completely different.   The compressor system
using compressed Freon gas circulated through evaporator coil(s) places cold in those compartments. ????

It is a different way to do about the same thing.  That being migrating heat energy to a cold source.

But we have to take the speaker at his word.   It's interesting that he could understand the former
clearly but not the latter in his explanation.   Somehow I sense technical writing and lack of proof reading
in preparing for his presentation. 

Good catch there

 

[TMG51]

After posting this thread and reading through the replies, just this week I happened to pick up a used book and read a story from H.P. Lovecraft about a creepy man living in a boarding house, with a strange medical condition which required him to always be cold. It went on to describe in detail how the man cooled his quarters using a system of ammonia absorption tubes....

Just odd to run into such a story while also reading into the workings of my refrigerator!

 

[DannyB1954]

I have read about using solar power with an ammonia absorption system for making ice in the desert. A web search on solar powered ammonia absorption refrigeration will bring up lots of info.

Maybe someday they will have a rv model.

 

[eDJ_]

Just last night I saw a Youtube video of how a Guy was using a group of Harbor Freight Solar panels
to run a small Ice Making Machine.

[video=dailymotion]