New 4.3 & 6.7 fridge info

[Jubal]

ETI uses Dometic RM8551- 4.3 and RM8555- 6.7 refers. You can substitute a 1 or 5 for the X in RM855X as you choose. Kenny did not say they (7 series) cooled better, just that he is not aware of any complaints. He looks you in the eye when he speaks to you and speaks his mind. Kenny said he does not have the time, resources, or inclination to own a TT and travel.

[Rossue]

Bob- what I should have said was no search results came up with the X in the model #'s. From your last sentence "In conclusion: Kenny says that the older RM755X models have better insulation, more heat exchange area, and a larger volume of refrigerant than the current RM855X model refers", one might believe there could be better performance in the RM7555 if the statement is factual.

[PGDriver]

I think that if this fridge issue isn't solved by the time my build sheet must be finalized I will ask Reace to install an older model fridge. Even if it is bigger and I loose the cupboard above the fridge at least it will function properly. The fridge in our Escape 19 had to be watched carefully as even on a hot day lettuce and other things could be frozen this was the same in the units we had before in our campers. I think Dometic has built a lightweight fridge at the expense of functionality, after researching fridges I don't think the cooling unit is large enough and there probably isn't enough insulation. This is to bad because it is a nice design, maybe its time to find a proven unit and move on... just my 2 cents worth.

[rbryan4]

Originally Posted by Rossue

Bob- what I should have said was no search results came up with the X in the model #'s. From your last sentence "In conclusion: Kenny says that the older RM755X models have better insulation, more heat exchange area, and a larger volume of refrigerant than the current RM855X model refers", one might believe there could be better performance in the RM7555 if the statement is factual.

Yeah, I've heard one other person say the 7 series were better than the 8 series -- and that's it. Online research comes up empty on the subject. Dometic even encourages people to "upgrade" their 7 series for an 8 series, with a nice little reference chart showing the equivalent model for fit. Maybe that's just them wanting to sell more fridges, but I don't see anything online providing evidence the 7 series is better.

Even after all these threads and all this research, nobody has actually pinpointed the cause of the poor performance on some of the fridges.

Still leaning toward using an AC/DC fridge, and being the guinea pig....

[KarenH]

Older models may not be available:

RV Refrigerators - Dometic

[escape artist]

Originally Posted by Jubal

ETI uses Dometic RM8551- 4.3 and RM8555- 6.7 refers. You can substitute a 1 or 5 for the X in RM855X as you choose. Kenny did not say they (7 series) cooled better, just that he is not aware of any complaints. He looks you in the eye when he speaks to you and speaks his mind. Kenny said he does not have the time, resources, or inclination to own a TT and travel.

Hi: jubal... I'm beginning to believe that "New and improved" really means cheaper to mfg. The reason Reace stopped using the 7series refers was Dometic stopped making them. Too many cooling issues and failures. Seems like they didn't learn anything except how to increase their profit margin with the 8series!!! I really like the electronic controls, the blue light, and the removable freezer compartment.
All this talk about refers has got me checking ours daily. Set on max. 5 bars and 120V by morn. the refer was at 32*F and covered in condensation. On our last trip home I believe the propane flamed out, and never re lit, causing the rise in temp into the red zone on the old thermometer. Alf
escape artist N.S. of Lake Erie

[Parker]

Anyone have a link to the (old) blowing out problem? Reace mentioned it recently, and I think cpaharley and/or Jon addressed it once upon a time. I think we may be having that issue as well. I'd like to do what I can to control the inflow through the lower vent, but this also seems counter to getting enough airflow up through the fins for the under-performing cooling system.

[reace]

Good morning!

Well, today I came in and opened the fridge (which has 18 bottles of water in it) and the temp is at 1 C. So far so good. Fridge fins are at -1 C and freezer fins are at -20 C. It is supposed to get hot again today, so I will keep opening the fridge throughout the day and see how she goes!

Reace

[Jubal]

Originally Posted by Rossue

Bob- what I should have said was no search results came up with the X in the model #'s. From your last sentence "In conclusion: Kenny says that the older RM755X models have better insulation, more heat exchange area, and a larger volume of refrigerant than the current RM855X model refers", one might believe there could be better performance in the RM7555 if the statement is factual.

It is also interesting to note that the dumetic 7 series refers use more energy. Is there a correlation between energy usage and cooling capability ?
Sigh, as my alter ego pointed out that $90 for a interior fans buys a lot of ice or is 1/3 of the cost of a very well insulated cooler.
In the course of discussion it would be helpful top post the size of refer you have or are making reference to.

[GerriJ]

Originally Posted by reace

Results with the Fridge Fix fan? Unfortunately I did not have good success. This also played a bit in the drop in temp before we hit the road. Side note, I now had the fridge set on max and figured it will shut off when it needs to as I did not want to gamble with a lower setting. On a few mornings, with the fridge cooled down nicely, I would switch the inside fan on to see if I could get it colder, and the temp would go up. I tried leaving it on longer hoping it would reverse itself and it never did.
Reace

Is it possible that the Fridge Fix fan, which is supposed to circulate quite a bit of air, is actually putting pressure on the door seals and causing cold air to escape the fridge with the unintended result of being replaced by warm air from inside the trailer?

[rbryan4]

Originally Posted by reace

Good morning!

Well, today I came in and opened the fridge (which has 18 bottles of water in it) and the temp is at 1 C. So far so good. Fridge fins are at -1 C and freezer fins are at -20 C. It is supposed to get hot again today, so I will keep opening the fridge throughout the day and see how she goes!

Reace

Thanks Reace.

[cpaharley2008]

Originally Posted by reace

Good morning!

Well, today I came in and opened the fridge (which has 18 bottles of water in it) and the temp is at 1 C. So far so good. Fridge fins are at -1 C and freezer fins are at -20 C. It is supposed to get hot again today, so I will keep opening the fridge throughout the day and see how she goes!

Reace

Is this on propane or 120v and do you have any pictures of the holes drilled? Thanks

[reace]

Well, the fridge seemed to hold temp at 1 C until about 12 ish, then I left the door wide open for about 5 min to make sure it lost the majority of its cool...other than the water bottles. The thermometer went up to 12 C. By 2ish, it was down to 5 C and at 4 it was down to 2 C. Using IR thermometer, fridge fins sitting at 0 C and freezer fins sitting at -20 C. It looks like I haven't lost a lot of cooling out of the freezer and could probably drill a couple of more holes... I will try that and turn the temp setting down tonight and see how it does tomorrow.

Jim, sorry I don't have pictures yet. I used a 1/2" spade bit and drilled the holes closest to the freezer door. Less chance of covering the holes this way.

When I pull the shelf out to drill more holes, I will take a photo.

Reace

[reace]

Let see how this works

Reace

[cpaharley2008]

Are you still using the interior fans to move the air around? Thanks for the pictures, I think this will help a lot.

[reace]

No fans and fridge is running on propane. I have the trailer closed up with no A/C on so it is quite warm inside the trailer. Cooling down the interior will only help...I will see how it is tomorrow on a lower setting and I will turn A/C on after lunch.

Reace

[wayne_m]

So why Dometic? What else is out there?

[rbryan4]

Originally Posted by wayne_m

So why Dometic? What else is out there?

The two absorption units most rv dealers in North America offer are Dometic and Norcold. Asking which is better is a bit pointless. Plenty of issues reported online for both brands.

[Klem]

Very interesting:

From http://www.lets-getaway.com/caravanfridges.htm

There are more tips on the site.

The article from which the following extract on the climate class rating of refrigerators is reproduced by express permission, Collyn Rivers, Caravan & Motorhome Books, Broome, WA 6725. This article is protected by Copyright. Books - Caravan and Motorhome Books

Climate Class Ratings

I to explain here just what I mean. A number of fridges sold in Australia are marketed as 'tropicalised'. Whilst this is a reasonable description of their design and construction, the term 'tropicalised' can unintentionally mislead those not familiar with fridge technology.

The increasingly accepted European Union (CEN) fridge performance standard, includes so-called 'Climate Classes' in which the most stringent is Climate Class T. And that 'T' stands for Tropical. So in the way that 'oils ain't necessarily oils', a 'tropicalised' fridge ain't necessarily Climate Class T.

There are four (CEN Standard) Climate Class ratings.

Fridges rated 'SN', and 'N' (which stands for Sub Normal, and Normal respectively) are designed and rated to work up to 32 degrees C.

Fridges marked 'ST', (which stands for Sub Tropical) are designed and rated to work up to 36 degrees C. Those marked 'T' (which stands for Tropical) are designed and rated to work up to 43 degrees C.

A correctly installed fridge Climate Class rated fridge can be relied upon to work satisfactorily up to the highest ambient temperature for which it is rated. But once past that temperature, cooling performance is likely to drop off. If, for example, you have a Climate Class SN or N fridge (ie. designed for 32 degrees maximum), but it's 42 degrees outside, the beer in that fridge is likely to be up to ten degrees C warmer.

So if you are planning to spend time in places that are very hot, it is prudent to use a 'T-rated' unit. I have yet to encounter anyone even locally using a correctly installed 'T-rated' fridge that was not completely satisfied with its performance. And I live in the Kimberley which is one of the most consistently hot areas of this country.

Do note that the European Union Standard that includes Climate Class ratings is not obligatory in Australia. Nevertheless Dometic and a few other fridge vendors market fridges in Australia that have the 'Climate Class' rating noted on their compliance plate (which you'll find inside the fridge). Climate Class T fridges were for example fitted in several display Winnebagos on display at the Casino Rally and many CMCA members have recently bought them.

Be clear regarding this: a statement that a fridge is 'tropicalised' does not imply that it meets Climate Class 'T' requirements.

Dometic states that its fridges that do meet the 'T' standard (and are designated accordingly on the compliance plate) are the larger models RM 2453, RM 2553, and RM 4601. The company claims only that its smaller fridges are 'tropicalised'.

[hotfishtacos]

Klem, so Myron's plate states that his 8551 (4.3) is a Climate Class SN. This means it should operate up to 32 degrees C?...or 89 degrees F? Why are SN and N rated the same?