Absorption refrigerator in hot / cold temps

[Kirk]

And considering we're going to be sharing a relatively small space for a couple of months, I think it's a good idea to prep as much as possible.

It is issues like that which are making the new, 12V compressor type refrigerators so popular for new RVs and boats. They do not have the problems of an absorption unit.

 

[oldwildman]

I have this problem in this Class A.

But works well when I am not driving in the extreme heat. The engine heat blows on my propane tank!

Other than that, this new large (4-door) propane refrigerator in this class A works perfectly in all weather.

In my older Y2K motorhome, the freezer works well in the heat, not so much with the refrigerator section, even when adjusted to max cold. So what I do when it gets hot (such as the mid-90's when I was in Organ Pipe last month), is take some ice packs (not real ice, the frozen packs) out of the freezer and put them in the refrigerator. Helps a lot. A full refrigerator with lots of cold stuff inside helps keep it cool.

-Don- Needles, CA

Yes, we found that a little ice goes a long way. This summer we found out our unit was starting to go bad on a fairly hot, mid 80's, summer day. Freezer was still in the high 20's but frig was about 50. Bought a large bag of ice and put in in a large tray in the frig. Not long after the frig was in the safe zone again. Freezer caught up that night when it got cooler. Ice was still there at the end of the trip. I guess they're insulated well.

Headed to south Florida in a couple of weeks with the new JC Refrigeration unit. Counting on it to do the job.

 

[DonTom]

They do not have the problems of an absorption unit.

And vice versa. Absorption units don't need a lot of battery and work well enough, IMO.

-Don- Needles, CA

 

[DonTom]

Yes, we found that a little ice goes a long way. This summer we found out our unit was starting to go bad on a fairly hot, mid 80's, summer day. Freezer was still in the high 20's but frig was about 50. Bought a large bag of ice and put in in a large tray in the frig. Not long after the frig was in the safe zone again. Freezer caught up that night when it got cooler. Ice was still there at the end of the trip. I guess they're insulated well.

Headed to south Florida in a couple of weeks with the new JC Refrigeration unit. Counting on it to do the job.

Yep, that sounds like my small Dometic refrigerator in my Y2K Class C motorhome.

The large 4-door Norcold in this Class A works perfectly--other than the engine heat problem when above 100F or so. Obviously, they made some improvements over the years in the absorption units over the years. It is a bit on the loud side, however. I can hear the flame as I type this. I assume it uses more propane than the older units.

-Don- Needles, CA

 

[Larry N.]

One more trick . . .

If you have an outside awning on the fridge side, then lower the awning in hot weather to shade the fridge area.

For those who have such an awning, be careful where, and for how long, you do that. Out in the west (Rocky Mountains, deserts, etc.) it's not uncommon for strong wind gusts to show up "out of nowhere." I've seen more than one awning, even tied down, get wrapped around the roof from these gusts, sometimes coming with no previous indication of wind at all.

So be aware...

 

[DonTom]

For those who have such an awning, be careful where, and for how long, you do that. Out in the west (Rocky Mountains, deserts, etc.) it's not uncommon for strong wind gusts to show up "out of nowhere." I've seen more than one awning, even tied down, get wrapped around the roof from these gusts, sometimes coming with no previous indication of wind at all.

So be aware...

Or else this happens!

-Don- Burnt Well, AZ

 

[RayIN]

I considered that but worried about the bulb breaking while traveling. We're in PA and the roads can get a bit rough at times. Vibration can also be tough on incandescent filaments. The little ceramic heater I bought is very small and I can strap it down.

Take a look at reptile heaters, they have a normal light bulb screw type base and of course are 120VAC. They come in 40,60 and 100W sizes; lots of heat, no light, nor glass to break.
That said, your fridge should operate just fine if you tape a section of cardboard/sheet aluminum on the bottom exterior vent door.
As to cooling; your present fans should keep the fridge operating fine IF, you keep the doors closed. Make a plan to get what you want from the fridge before you open the door. Grab what you need and quickly close the door. Absorption refrigerators have a very slow recovery time compared to your home fridge, and every time the door is opened the chilled air falls out, only to be replaced with warm humid cabin air.

 

[JaycoLovers]

an additional tip....like someone mentioned above, avoid unnecessary opening and closing of the fridge when it's hot. When we relied on an absorption fridge, I found that keeping a couple milk jugs of water in there helped regulate the temp. It offset the large temp swing that the fridge goes through while trying to recover from opening/closing...obviously we could only fit them in there when we had room for them. But this thermal mass helped regulate the system. They take overnight to get cold...but once they are, they will "absorb" a lot of the warm air that gets into the fridge resulting in a better average temperature for your perishables.

 

[the4quads]

I've tried those rough service bulbs before in the garage and at work. While they are a bit more durable, I still managed to ruin them in a short amount of time.

My son had some problems in cold weather so he used a Reptile heater instead of a bulb.

Ceramic Heat Lamp for Reptiles​

 

[oldwildman]

an additional tip....like someone mentioned above, avoid unnecessary opening and closing of the fridge when it's hot. When we relied on an absorption fridge, I found that keeping a couple milk jugs of water in there helped regulate the temp. It offset the large temp swing that the fridge goes through while trying to recover from opening/closing...obviously we could only fit them in there when we had room for them. But this thermal mass helped regulate the system. They take overnight to get cold...but once they are, they will "absorb" a lot of the warm air that gets into the fridge resulting in a better average temperature for your perishables.

We normally don't drink the faucet water. So there's a large stock of drinks in the frig. It does seem to help any temperature swings. I also keep a stock of ice packs in the freezer for the same reason.

 

[udidwht]

An incandescent light bulb can provide plenty of heat for that small area

An 'instant heat pack' will do even better and no electricity.

 

[Lou Schneider]

Since the discussion has drifted from hot to cold weather operation I changed the thread title to match.

 

[JudyJB]

If you are in hot weather, you might also consider using a small cooler and putting water bottles and drinks in it, along with a bag of ice to put in drinks. This will help reduce the number of times the refrigerator needs to be open. A shade on the outside also helps, but I agree that awnings should never be left open on an RV if you are gone for more than half an hour. Too much chance, especially in the west, of a sudden storm coming up and causing it to flap and pull off your rig causing a lot of damage. I also never leave my awning up overnight for same reason--storms can be very sudden.

 

[Lou Schneider]

If you are in hot weather, you might also consider using a small cooler and putting water bottles and drinks in it, along with a bag of ice to put in drinks. This will help reduce the number of times the refrigerator needs to be open. A shade on the outside also helps, but I agree that awnings should never be left open on an RV if you are gone for more than half an hour. Too much chance, especially in the west, of a sudden storm coming up and causing it to flap and pull off your rig causing a lot of damage. I also never leave my awning up overnight for same reason--storms can be very sudden.

I've used absorption refrigerators in hot weather (105+ degrees) and never had to do more than set up a small fan to blow air upwards over the cooling coils.

The problem is the refrigerator needs airflow over the coils to carry away the waste heat. In cooler weather the hot coils act like a chimney and carries the waste heat out the roof vent. In hot weather there isn't enough temperature difference between the coils and the outside air to set up the thermosiphon and you need a fan to supply the needed air movement.

 

[John From Detroit]

I've used absorption refrigerators in hot weather (105+ degrees) and never had to do more than set up a small fan to blow air upwards over the cooling coils.

Same here. also low temps and no problems as well they are heat powered.

 

[Larry N.]

A shade on the outside also helps, but I agree that awnings should never be left open on an RV if you are gone for more than half an hour.

In some areas that's too long- for example a number of years ago we were in the Palo Duro Canyon Park just south of Amarillo with a group. At supper time we all gathered at one trailer for supper. About halfway through the meal a sudden gust came up. Unfortunately one couple had left their awning extended and the gust immediately wrapped it over the roof of the trailer. It was less than 100 feet away from where we all were, but it was over with almost before they could even get to their feet.

It was a trailer like the first picture below (sorry, didn't get a pic of the problem). Second picture was our supper table and some of the crew.

So be very careful about leaving them extended...

 

[8Muddypaws]

I’m in California and have never had to deal with extreme cold. But I do have advice for high heat. If you add fans to move air through the cooling unit it’s best to put fans at the top of the ‘stack’ forcing hot air out. It has to do with eddies, laminar flow and such.

Back when we had a Norcold 1200 series I put four 12v computer fans on the inside of the exhaust vent and our refer stayed Cold enough no matter how hot it got outside, as long as Mrs. muddypaws didn’t leave the door open.

That cooling unit leaked all the magic juice and became scrap metal. We replaced it with a JC Refrigeration 12v dual compressor cooling unit. No need for additional fans and super cold. (But a bit noisy). We took it to Phoenix in September and it worked fine.

 

[John From Detroit]

But I do have advice for high heat. If you add fans to move air through the cooling unit it’s best to put fans at the top of the ‘stack’ forcing hot air out. It has to do with eddies, laminar flow and such.

They make a Solar Fan top cover for RV fridges.. Interesting item do not know how good it works.

 

[bigbAZ]

But I do have advice for high heat. If you add fans to move air through the cooling unit it’s best to put fans at the top of the ‘stack’ forcing hot air out. It has to do with eddies, laminar flow and such.

That's how I understand it and when I did mine I used 2-8" PC fans at the top vent, on low speed so they gently push the hot air out and don't create turbulence.

 

[Lou Schneider]

I’m in California and have never had to deal with extreme cold. But I do have advice for high heat. If you add fans to move air through the cooling unit it’s best to put fans at the top of the ‘stack’ forcing hot air out. It has to do with eddies, laminar flow and such.

That may be true in theory, but in practical terms setting a fan to blow air up past the coils works fine. It really doesn't matter what happens to the heat at the top of the enclosure, it will work it's way out eventually. The key factor is restoring airflow past the coils behind the fridge.