Fridge Performance Survey

[ZachO]

A poll would probably be better, but this will work...

I'd appreciate it if people would post some info about how well their fridge works.

I've only had two campers, but in both, one with a brand new fridge, I've had a lot of trouble cooling adequately when outside temps get in the 80s and higher.

So...

Does your fridge vent out the ceiling or just an upper vent in the side of the camper?

Once the outside temps get into the 80s or higher, does your fridge stay in the safe zone (40 degrees or cooler)?

If you had issues in the past, did you find a "fix"?



My fridge works great with temps up to the 60s. In the 70s it's "ok", once in the 80s, it's barely holding on at 40-45 degrees. Mine is the smaller type with the upper vent in the side of the trailer, not out the ceiling.

I've cleaned the orifice, burner, and chimney. I added a baffle to help direct air flow over the fins. I have a fan installed in the upper vent to clear out hot air. I've pulled the fridge and run on AC then flipped it. I have a fan inside the fridge.

I know this is a camper and not a house, but...people live in these things year round, right? I'm mostly living in mine during the summer. We finally got temps in the high 70s, low 80s. On Thursday I came home from work and it was 60 degrees inside my fridge. So Friday I remembered to switch on the exhaust fan in the upper vent. About 42 degrees when I came home from work that day.

I'm in the sun for half the day. Shade from about 3pm on. Fridge vent is on the shady side of the trailer.

Basically that means I'll be using a cooler this summer and the fridge will be for storage. Is that just "how it is", or do some of you have better luck?

[David B.]

Zach, we went throuh all the steps outlined in FGRV forum on how to get the most out of your 3 way, and like you, none proved to help enough to consistantly have adequate cooling for higher temps. We live in the Phoenix Arizona area, so cooling is really important. In our last two trailers I had switched out from a 3 way gas absorption to a danfoss compressor refrigerator style refrigerator.....wow, what a difference. Now we have instant cooling within minutes not hours, and recovery from opening the door also is minutes. It doesn't matter if it is 110 degrees or 40, the temp will stay the same inside. The compressor is quiet, but not as quiet as the silent 3 way, but is quieter than our home refrigerator. Like a home refrigerator, the heat is vented into your living area, but feels like less than the amount of heat if you were to light a single candle. In our Scamp it vented out through the existing vents from the previous refrigerator. You can figure the refrigerator using 25-35 amp hours of battery energy per day, so while boon docking, we use 150 watt solar panel, and we do have a generator if necessary. In the summer we typically live in our trailer for 3-4 month stretches, and shorter local trips during the winter. I would never want to have to go back to an absorption refrigerator. In our 25' toyhauler we had a Dometit refrigerator/freezer (almost as large as our home refrigerator) that had the heat exhaust through the roof, with a small fan to move the air out when needed, and it did preform much better than our side vented refrigerators.
I hope this helps in your survey.
Dave & Paula

[padlin00]

In my Starcraft the fridge worked fine, probably because I never put a thermometer in it.

In the Escape I installed a thermometer in both the fridge and freezer. Had the original frdge replaced for lack of cooling. The 2nd one works fine unless I travel when it's warm out for very long, then it goes up. Good thing is it cools back down once I stop pretty quick. It gets above 40 fairly often, I stopped worrying about it unless it goes over 50.

[Dave Gray]

Just had a new Dometic fridge installed last year and had the same problem this week while camping. It was in the 90's and the campsite had 30 amp electric hookup. Could not keep it in the safe zone even at the highest cooling setting. Thought there was an issue with the electric hookup so went propane but still had same issue. Glad I had an ice chest backup. The trailer has a side vent but the fan was removed when the new fridge was installed. I'm going to reinstall a fan to see if that helps. I camped in Santa Cruz last year and had no problem when on propane. I have a tech coming out next week to give the fridge a once over but it sounds like maybe a common issue in hot weather.

[Leslie14]

HI,

Could you please give me more information about the refrigerator you installed? I am looking to replace mine. Thank you.

Leslie

[gordon2]

Originally Posted by Dave Gray

... The trailer has a side vent but the fan was removed when the new fridge was installed. I'm going to reinstall a fan to see if that helps. ...

I am of the opinion that a roof exhaust vent makes a world of difference. A fan in the side vent area might have about the same positive effect.

All the other tips and tricks have been discussed many times before.. shady site or shade the fridge, pack full but loose so air flows inside, fans to help air flow on the outside coils, small fan on the inside, open only when needed and as close the door as fast as possible, etc.

[Michael Pupeza]

Zach,
I have a 1993 Dometic 2607 fridge with the freezer door above the main fridge door. It's a nice size as frozen pizzas will fit in the freezer and lots of room in the fridge portion. It now works GREAT, staying at normal freezing and fridge temps up into the 90s - as high as I've been. It is vented up above the roofline with the flanged plastic cover. No fans are installed - not needed.
That said, I did replace the control board with a Dinosaur Replacement Board which works better and corrects some flaws in the original Dometic board - mainly multiple attempts at starting when flame blown out or starting without resetting, and better connection for flame sensor not depending on common ground. Also, about 5 years ago, the main cooling unit failed and I replaced it with an Amish rebuilt replacement (Much cheaper than a new fridge).
I only use it on propane (about 1300 BTU) and AC (about 1004 BTU) but almost never on 12V (773 BTU).
I feel sorry for those apparent many people who continually have dis-satisfaction with their fridges as I don't know what I've done right to not have any problems (anymore!).
Mike .....>

[Dave Gray]

My Dometic fridge is a RM2354.

[ZachO]

Thanks a lot so far!

It's looking like my hunch is right, based on the responses so far:

The roof vent fridges perform much, much better.

When I'm struggling to stay under 45, my friend with a bigger, stick-built trailer and full size fridge is complaining about frozen beer.

Seems like for us side-vent people, we have to do a whole bunch of tricks and add-ons to get decent performance.


I always boon-dock so I've been hesitant to go with the "dorm-fridge" style. I have 90W of solar, which only just keeps up with my use. No generator.

For now I'm going to consider installing a second exhaust fan and putting a metal plate between the chimney and coils/fins, since I saw a link to the Casita forum someone posted with that modification, saying it helped. But still...sounds like 40-50 degrees below ambient temperature is the most anyone gets out of these fridges, so once in the 90s...it's just going to be a losing battle.

Using a cooler for camping is no big deal. When I'm living out of the camper, it gets really annoying to live out of a cooler. Just seems like I have this nice camper with a stove, oven, bathroom and...fridge. It's all about expectations, I guess...When I'm "home", I don't like dealing with a cooler.

[biw314]

I just went through the standard fixes for these refrigerators this spring. Flipping, door seal, baffles, fans inside and out and insulation. The single most important thing was propane pressure. I found mine to be 8" WC and it should be 11" WC. I gained more than 10 F below ambient with that adjustment.

[SilverGhost]

I had this battle when deciding which trailer to buy and whether to get a 3 way or 12V. I have left my 12V on a GRP 24 battery and solar for 3 month in my driveway - still cold inside. My dad has had his Dometic 3 way repaired and replaced several times and it is giving a little trouble again.

My opinion - absorption refrigeration is a technology that is subject to minor variations and bean counters at the manufactures can cause poor performing products that put people off. Look at how well the much larger models work. I'd imagine that if the fridge had about another, say $200 spent on quality design and build that we wouldn't be having discussions like this.

Jason

[redbarron55]

I have a 12 /120 Norcold (Nevercold?) 704DE and now it works quite well.
These things have swing compressors which are like solenoids that vibrate back and forth driving the compressor pistons with them and not rotating.
The advantage is when they start they have no starting surge to overcome.
The drawback is that many work well on AC but not on DC because the chopper must operate on exactly 60 HZ. since the solenoid and spring are tuned for that frequency.
Mine didn't work right on DC for this reason, but the oscillator can be retuned to make it work right and now mine is OK.
That being said sometimes these are noisy with a 60 cycle buzz that is worrisome, but you get used to it.
My unit cools with the weather hot of cold and seems to make little or no difference since there is a thermostat in the unit that controls the running of the compressor.
I just added a 100 watt solar panel to the roof and a cheap controller and I am testing in in the driveway now. It seems to charge with the refrigerator running ot discharges only a little according to my wattmeter. It is hard to tell since the wattmeter reads the power coming from the battery or converter and somehow the solar system is not in the loop for the current shunt (evidently).
I tied the solar into the charge line from the TV since it is a large wire size and there is a junction box near the controller.
We will see if the solar system will maintain the battery while the fridge is on.
The average power consumption of the AC /DC 704DE is about 25 watts.
Hopefully I will never have to worry while towing or parked and off gallivanting around.

[Civilguy]

Originally Posted by ZachO

I've had a lot of trouble cooling adequately when outside temps get in the 80s and higher.

So...

Does your fridge vent out the ceiling or just an upper vent in the side of the camper?

Once the outside temps get into the 80s or higher, does your fridge stay in the safe zone (40 degrees or cooler)?

If you had issues in the past, did you find a "fix"?

Zach,

It sounds like you have been doing your homework.

We have a Casita with a Dometic RM2454, a 4.0 cu ft. 3-way refrigerator. The trailer came with Casita's cooling fan option. Being installed in a Casita, it is a side vent installation.

While the fan seemed to help "a bit", the refrigerator's performance deteriorated badly when operating on propane in 80+ degree weather last summer. The fan Casita installed is not installed at the top of the side vent. It pushes air upwards from lower down. It is controlled by a manually operated on-off switch.

I bought a pair of fans and a couple of super-cheap Chinese-made PWM control boards last year. I intend to mount these fans at the top, aligned to exhaust the hot air out through the vent. They are still awaiting installation.

Webmaster Gene of the Casita forum apparently plumbed a little exhaust stack extension outside of the body of his trailer through the plastic vent cover. I don’t recall if he did this with copper plumbing or what he used.

There is also a Dometic 3776 flue extension kit which is apparently only sold in Australia.

https://www.dometicrvcentre.com.au/o...-flue-kit-3776

It seems I've also seen mention of insulating the cavity around the fridge.

Here are some additional links on the subject that I have bookmarked.

Refrigerator Cooling - The Casita Club Forum - The Casita Club Forums

http://www.casitaforum.com/invboard/...rigerator-fan/

http://www.casitaforum.com/invboard/...e__hl__baffles

I think getting the hot air out is key, and the side vent units don't do that well. The fridge is attempting to operate in a temperature that is much higher than ambient, and there is space between the fridge and the fiberglass that allows this hot air to surround the fridge. I found the "counter top" over the fridge to be quite hot to the touch.

I am also intrigued by the question of whether the LP pressure is correct. I do know that the propane generates more more heat in our installation than operating on 120 volt. So, that is why I have been focused on removing the excess heat.

[Civilguy]

Here's a couple more documents I've collected on this subject.

[Civilguy]

Huh. I tried to upload two documents but one was too big.

Here's the other file, now separated into three files.

[Joe Romas]

I don't know if this is one of the links Civilguy listed but this one gives all you need to know on how to get good refrigerator performance.
https://www.casitaforum.com/invboard...ge-run-better/

You need to separate the HOT heat from the flame, assuming propane operation, from the refrigeration system's heated air and that can be done with baffles in the venting.

Ours works very well IF the door is not opened too often for too long.

Joe

[RandyNH]

Originally Posted by Civilguy

Zach,

It sounds like you have been doing your homework.

We have a Casita with a Dometic RM2454, a 4.0 cu ft. 3-way refrigerator. The trailer came with Casita's cooling fan option. Being installed in a Casita, it is a side vent installation.

While the fan seemed to help "a bit", the refrigerator's performance deteriorated badly when operating on propane in 80+ degree weather last summer. The fan Casita installed is not installed at the top of the side vent. It pushes air upwards from lower down. It is controlled by a manually operated on-off switch.

I bought a pair of fans and a couple of super-cheap Chinese-made PWM control boards last year. I intend to mount these fans at the top, aligned to exhaust the hot air out through the vent. They are still awaiting installation.

Webmaster Gene of the Casita forum apparently plumbed a little exhaust stack extension outside of the body of his trailer through the plastic vent cover. I don’t recall if he did this with copper plumbing or what he used.

There is also a Dometic 3776 flue extension kit which is apparently only sold in Australia.

https://www.dometicrvcentre.com.au/o...-flue-kit-3776

It seems I've also seen mention of insulating the cavity around the fridge.

Here are some additional links on the subject that I have bookmarked.

Refrigerator Cooling - The Casita Club Forum - The Casita Club Forums

http://www.casitaforum.com/invboard/...rigerator-fan/

http://www.casitaforum.com/invboard/...e__hl__baffles

I think getting the hot air out is key, and the side vent units don't do that well. The fridge is attempting to operate in a temperature that is much higher than ambient, and there is space between the fridge and the fiberglass that allows this hot air to surround the fridge. I found the "counter top" over the fridge to be quite hot to the touch.

I am also intrigued by the question of whether the LP pressure is correct. I do know that the propane generates more more heat in our installation than operating on 120 volt. So, that is why I have been focused on removing the excess heat.

I had the 2454 and could never get it to cool effectively, last summer traveling through Utah wouldn't go below 50°, with the extra exhaust fan to pull more heat out.

As you point out, airflow is key and keeping the vanes in back as cool as possible, so not only are you fighting ambient temp but also the incredible heat produced by the propane fired process.

All of this is why I removed it and replaced it with a Nova Kool 5810, it has a larger interior and smaller exterior, height wise. This allowed me to completely seal off both exterior vents, elevate the mount so that there is space below it and above it and place a small fan on the top, it now draws inside air from below the fridge, floor level, draws it up across the rear vanes and exhausts it over the top back into the trailer, which is air-conditioned anyways or if nice enough the windows are open, either way the fridge will never use air hotter than 80°degrees to try and run.

We'll see how it performs this summer and if necessary the top exhaust vent can be reopened to vent if necessary.

[ZachO]

Good info! Thanks.

I think my best bet right now is to install some sheet metal between the chimney and fins, and add that upper deflector. I hadn't seen that before. From there I'll look into another fan or something like that.

So those pdfs show...mostly a kit for the chimney? Something that separates the hot air coming out of the chimney from from the cool air coming in the bottom vent and flowing over the cooling fins?

I added a baffle to mine already, but judging by some of the photos I've seen, I could actually extend it out a bit farther. I still have maybe one to one and a half inches of space between my baffle and the fins.

I don't really know when my "weekend" days are going to be right now...but when I have a few days off, I'll start on the sheet metal fabrication project

[redbarron55]

A baffle to make sure that all of the air goes through the cooling radiator at the top is important.
A good chimney to the roof would help, but a fan pulling the air out might help as well.
The key is that the air has to cool the right parts fro the thing to work.

[biw314]

I second the baffle. I put one yesterday and gained about another 10 F below ambient. I think it was the single most important I did to improve the performance--propane pressure adjustment was probably a close second. Mine goes all the way in to the back of the fridge so the middle part is now right up against the "wall".