Community Forums

MrMudstud · 08-21-2015, 08:48 PM

I have a Dometic NDR 1292, 12 cu ft side by side refrigerator. The difference between the frig vs freezer temperature on the first setting is 38 to 16 degrees. On the highest setting, the refrigerator cooled down to 24 and the freezer is 7 degrees. I check the temperature in the morning before it starts getting hot. The morning temp are running around 80 degrees when the testing is done. Does that sound about right compared to your unit or What is the difference between your unit?
Thanks in advance for help.

Nomad Mike · 08-21-2015, 09:50 PM

Brand new Norcold 1210 double door is around 35/10 give or take a degree on 5.

Gary RVRoamer · 08-22-2015, 11:11 AM

My 11 year old Norcold 1200 runs at about 35-38 in the fridge and -7 to zero in the freezer. That's on a "5" setting (out of 9).

An absorption fridge has two chiller (absorption) stages. The first one chills the freezer and then the remaining coolant is run through another absorption stage to chill the fridge part. As cooling unit performance declines, there is less cooling left after the first stage, so the temperature difference gets greater (fridge is warmer). As it declines further, the freezer starts to get warmer too.

I would say your coolant unit is marginal. You may need some improved air circulation in the back (over the cooling unit fins) or some better insulation around the back of the frame. The air in the back (outside) compartment runs well over 120 degrees on a warm day and warms the fridge if it gets around the sides and top of the box.

MrMudstud · 08-22-2015, 01:26 PM

Quote:

Originally Posted by Gary RVRoamer

My 11 year old Norcold 1200 runs at about 35-38 in the fridge and -7 to zero in the freezer. That's on a "5" setting (out of 9).

I would say your coolant unit is marginal. You may need some improved air circulation in the back (over the cooling unit fins) or some better insulation around the back of the frame. The air in the back (outside) compartment runs well over 120 degrees on a warm day and warms the fridge if it gets around the sides and top of the box.

Thanks Gary for your insight as yours is surly working super. The testing I am doing is in my RV garage with both compartments empty, and have both my inside and outside fans off. I was getting an idea of where I stand as the refrig performance on a regular setup. I need to turn on the fans and see if there is any change. Thanks Again.

cimplexsound · 08-22-2015, 09:18 PM

I also have a Dometic Freezer/fridge. My however is the freezer on top of the fridge. I have found with the Dometic fridges putting your thermostat on 4 works best. Typical fridge temperature should be 41.2 Degrees F with 31% percent humidity. At least this is my experience. The freezer should be anywhere from -0 Degrees F to -29 degrees F with about 21% percent humidity. If you are finding the fridge is over chilling food or even freezing food at the current setting, trying moving the dial to 3 or 2 until you get just the right temperature. In Anycase the fridge should stay 41 F degrees all the time. 43F is to high and at 45F food will began to spoil. 16 F degrees things like milk would be ruined from freezing. So just have to play with the dial until you get it right. So I hope this will be of some help.

1979 Dodge Tioga Class C 24 foot. 1987 Fleetwood Bounder 34 Foot.

rgvtexan · 08-22-2015, 10:04 PM

Put a couple milk jugs filled with water in the freezer and 4 in the frig and try it again.
The difference could surprise you.

Gary RVRoamer · 08-23-2015, 09:28 AM

Yes, put something in the fridge. An absorption fridge needs stuff inside to help stabilize the temps. Also, put the thermometer in a glass of water. With no forced air circulation inside, the air temperature in any one spot os not a reliable measure, but the water will chill to the the same termperatures you could expect for your food. Both Norcold & Dometic recommend immersing the thermometer in a liquid to get a usable reading.

MrMudstud · 08-24-2015, 01:11 PM

I did what was asked to put the thermometer in a glass of water. Also, turned the fan on inside under the cooler fins. During the night it was below 80˚ til 8:00 am when I checked it again. The temp inside the frig was the same 38-39˚. I calibrated my thermometers in a glass of ice water and set them both to 32˚ before all this testing. At best they may be 1˚ to 2˚ off.

Thanks again for all the help.

Cat320 · 08-24-2015, 05:48 PM

A solution to all these problems is a residential refer. We got our first one in June...it's wonderful!

Cliffy · 08-24-2015, 06:07 PM

Just had my 39 year old "Elixer" refer out on a trip. It was freezing the ice hard in the freezer and held 34-37F in the box with 84 degrees outside and down to 28 at night with 60 degrees outside at 7600' elevation. On the same trip down in the desert at 108 outside the freezer still kept the ice good but the box went to 45 degrees. I suspect not enough insulation in the unit for better performance. Used 4 lbs of dry ice in box the lower to 33F
I also suspect a little leakage at the points where the coils come thru from the back of the unit (to be worked on later).
Anyone tried to design more insulation in the two sides and top of a unit?

Never heard of a cooling unit getting lower performance as it aged. Can someone educate me?

JFXG · 08-24-2015, 10:49 PM

I have the same Dometic NDR1292 as the OP. I run on setting 4 (of 5) and maintain 38 deg in the box and 11 deg in the freezer. Has been stable like this for the three years I've owned it, though the coach and the unit are 13 y/o. The only difficulty I have is that on setting 4 the condensate that forms on the fins in the refrigerator freezes. Every second or third night I just reduce the setting to 3, the ice melts away, then back to 4 in the morning. I wish I could defrost the freezer as easily!!

Cat320 · 08-25-2015, 12:02 PM

11 degrees is way to warm for the freezer. Here's what's recommended:

"34°F - 40°F is the ideal refrigerator temperature range. Some Web sites just say under 40°F, but not so cold to freeze fresh foods. Dairy products and meats keep best at the low end of the temperature range.

A freezer should be set at 0°F, or lower, if possible. If the temperature gets warmer than +5°F, ice cream will be too soft and won't keep well. A properly working food freezer will operate in the range of -10°F to +2°F, and may go up to around +8°F briefly during the defrost cycle if it is of the "frost free" type."

The residential refrig in our MH is a Whirlpool, they recommend 0 in the freezer and 38 in the refer.

530ktm · 08-25-2015, 12:19 PM

Quote:

Originally Posted by Cat320

A solution to all these problems is a residential refer. We got our first one in June...it's wonderful!

A residential refrigerator is great if you never go off the grid for any length of time. We seldom go with hook ups nor do we want to invest in a ton of batteries and such just to run a refrigerator. Our Norcold works great in this coach as well as the last and they have never let us down.

Gary RVRoamer · 08-25-2015, 03:48 PM

It's true that food deteriorates much more quickly at 10 F. than at 0 or -10. But few people store food very long in an RV fridge, so the difference is maybe not crucial. Except for the ice cream hardness, that is.

My Norcold 1200 will maintain zero or less without working hard, so I'm ok. And it also automatically defrosts the fins in the fridge every 47 hours. That lets the freezer temp come up a bit higher than I like for a few hours, though.